From: "Mike Pagano" <mpagano@gentoo.org>
To: gentoo-commits@lists.gentoo.org
Subject: [gentoo-commits] proj/linux-patches:4.18 commit in: /
Date: Wed, 15 Aug 2018 16:36:59 +0000 (UTC) [thread overview]
Message-ID: <1534351012.ad052097fe9d40c63236e6ae02f106d5226de58d.mpagano@gentoo> (raw)
commit: ad052097fe9d40c63236e6ae02f106d5226de58d
Author: Mike Pagano <mpagano <AT> gentoo <DOT> org>
AuthorDate: Wed Aug 15 16:36:52 2018 +0000
Commit: Mike Pagano <mpagano <AT> gentoo <DOT> org>
CommitDate: Wed Aug 15 16:36:52 2018 +0000
URL: https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=ad052097
Linuxpatch 4.18.1
0000_README | 4 +
1000_linux-4.18.1.patch | 4083 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 4087 insertions(+)
diff --git a/0000_README b/0000_README
index 917d838..cf32ff2 100644
--- a/0000_README
+++ b/0000_README
@@ -43,6 +43,10 @@ EXPERIMENTAL
Individual Patch Descriptions:
--------------------------------------------------------------------------
+Patch: 1000_linux-4.18.1.patch
+From: http://www.kernel.org
+Desc: Linux 4.18.1
+
Patch: 1500_XATTR_USER_PREFIX.patch
From: https://bugs.gentoo.org/show_bug.cgi?id=470644
Desc: Support for namespace user.pax.* on tmpfs.
diff --git a/1000_linux-4.18.1.patch b/1000_linux-4.18.1.patch
new file mode 100644
index 0000000..bd9c2da
--- /dev/null
+++ b/1000_linux-4.18.1.patch
@@ -0,0 +1,4083 @@
+diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
+index 9c5e7732d249..73318225a368 100644
+--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
+@@ -476,6 +476,7 @@ What: /sys/devices/system/cpu/vulnerabilities
+ /sys/devices/system/cpu/vulnerabilities/spectre_v1
+ /sys/devices/system/cpu/vulnerabilities/spectre_v2
+ /sys/devices/system/cpu/vulnerabilities/spec_store_bypass
++ /sys/devices/system/cpu/vulnerabilities/l1tf
+ Date: January 2018
+ Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Description: Information about CPU vulnerabilities
+@@ -487,3 +488,26 @@ Description: Information about CPU vulnerabilities
+ "Not affected" CPU is not affected by the vulnerability
+ "Vulnerable" CPU is affected and no mitigation in effect
+ "Mitigation: $M" CPU is affected and mitigation $M is in effect
++
++ Details about the l1tf file can be found in
++ Documentation/admin-guide/l1tf.rst
++
++What: /sys/devices/system/cpu/smt
++ /sys/devices/system/cpu/smt/active
++ /sys/devices/system/cpu/smt/control
++Date: June 2018
++Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
++Description: Control Symetric Multi Threading (SMT)
++
++ active: Tells whether SMT is active (enabled and siblings online)
++
++ control: Read/write interface to control SMT. Possible
++ values:
++
++ "on" SMT is enabled
++ "off" SMT is disabled
++ "forceoff" SMT is force disabled. Cannot be changed.
++ "notsupported" SMT is not supported by the CPU
++
++ If control status is "forceoff" or "notsupported" writes
++ are rejected.
+diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
+index 48d70af11652..0873685bab0f 100644
+--- a/Documentation/admin-guide/index.rst
++++ b/Documentation/admin-guide/index.rst
+@@ -17,6 +17,15 @@ etc.
+ kernel-parameters
+ devices
+
++This section describes CPU vulnerabilities and provides an overview of the
++possible mitigations along with guidance for selecting mitigations if they
++are configurable at compile, boot or run time.
++
++.. toctree::
++ :maxdepth: 1
++
++ l1tf
++
+ Here is a set of documents aimed at users who are trying to track down
+ problems and bugs in particular.
+
+diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
+index 533ff5c68970..1370b424a453 100644
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -1967,10 +1967,84 @@
+ (virtualized real and unpaged mode) on capable
+ Intel chips. Default is 1 (enabled)
+
++ kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
++ CVE-2018-3620.
++
++ Valid arguments: never, cond, always
++
++ always: L1D cache flush on every VMENTER.
++ cond: Flush L1D on VMENTER only when the code between
++ VMEXIT and VMENTER can leak host memory.
++ never: Disables the mitigation
++
++ Default is cond (do L1 cache flush in specific instances)
++
+ kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
+ feature (tagged TLBs) on capable Intel chips.
+ Default is 1 (enabled)
+
++ l1tf= [X86] Control mitigation of the L1TF vulnerability on
++ affected CPUs
++
++ The kernel PTE inversion protection is unconditionally
++ enabled and cannot be disabled.
++
++ full
++ Provides all available mitigations for the
++ L1TF vulnerability. Disables SMT and
++ enables all mitigations in the
++ hypervisors, i.e. unconditional L1D flush.
++
++ SMT control and L1D flush control via the
++ sysfs interface is still possible after
++ boot. Hypervisors will issue a warning
++ when the first VM is started in a
++ potentially insecure configuration,
++ i.e. SMT enabled or L1D flush disabled.
++
++ full,force
++ Same as 'full', but disables SMT and L1D
++ flush runtime control. Implies the
++ 'nosmt=force' command line option.
++ (i.e. sysfs control of SMT is disabled.)
++
++ flush
++ Leaves SMT enabled and enables the default
++ hypervisor mitigation, i.e. conditional
++ L1D flush.
++
++ SMT control and L1D flush control via the
++ sysfs interface is still possible after
++ boot. Hypervisors will issue a warning
++ when the first VM is started in a
++ potentially insecure configuration,
++ i.e. SMT enabled or L1D flush disabled.
++
++ flush,nosmt
++
++ Disables SMT and enables the default
++ hypervisor mitigation.
++
++ SMT control and L1D flush control via the
++ sysfs interface is still possible after
++ boot. Hypervisors will issue a warning
++ when the first VM is started in a
++ potentially insecure configuration,
++ i.e. SMT enabled or L1D flush disabled.
++
++ flush,nowarn
++ Same as 'flush', but hypervisors will not
++ warn when a VM is started in a potentially
++ insecure configuration.
++
++ off
++ Disables hypervisor mitigations and doesn't
++ emit any warnings.
++
++ Default is 'flush'.
++
++ For details see: Documentation/admin-guide/l1tf.rst
++
+ l2cr= [PPC]
+
+ l3cr= [PPC]
+@@ -2687,6 +2761,10 @@
+ nosmt [KNL,S390] Disable symmetric multithreading (SMT).
+ Equivalent to smt=1.
+
++ [KNL,x86] Disable symmetric multithreading (SMT).
++ nosmt=force: Force disable SMT, cannot be undone
++ via the sysfs control file.
++
+ nospectre_v2 [X86] Disable all mitigations for the Spectre variant 2
+ (indirect branch prediction) vulnerability. System may
+ allow data leaks with this option, which is equivalent
+diff --git a/Documentation/admin-guide/l1tf.rst b/Documentation/admin-guide/l1tf.rst
+new file mode 100644
+index 000000000000..bae52b845de0
+--- /dev/null
++++ b/Documentation/admin-guide/l1tf.rst
+@@ -0,0 +1,610 @@
++L1TF - L1 Terminal Fault
++========================
++
++L1 Terminal Fault is a hardware vulnerability which allows unprivileged
++speculative access to data which is available in the Level 1 Data Cache
++when the page table entry controlling the virtual address, which is used
++for the access, has the Present bit cleared or other reserved bits set.
++
++Affected processors
++-------------------
++
++This vulnerability affects a wide range of Intel processors. The
++vulnerability is not present on:
++
++ - Processors from AMD, Centaur and other non Intel vendors
++
++ - Older processor models, where the CPU family is < 6
++
++ - A range of Intel ATOM processors (Cedarview, Cloverview, Lincroft,
++ Penwell, Pineview, Silvermont, Airmont, Merrifield)
++
++ - The Intel XEON PHI family
++
++ - Intel processors which have the ARCH_CAP_RDCL_NO bit set in the
++ IA32_ARCH_CAPABILITIES MSR. If the bit is set the CPU is not affected
++ by the Meltdown vulnerability either. These CPUs should become
++ available by end of 2018.
++
++Whether a processor is affected or not can be read out from the L1TF
++vulnerability file in sysfs. See :ref:`l1tf_sys_info`.
++
++Related CVEs
++------------
++
++The following CVE entries are related to the L1TF vulnerability:
++
++ ============= ================= ==============================
++ CVE-2018-3615 L1 Terminal Fault SGX related aspects
++ CVE-2018-3620 L1 Terminal Fault OS, SMM related aspects
++ CVE-2018-3646 L1 Terminal Fault Virtualization related aspects
++ ============= ================= ==============================
++
++Problem
++-------
++
++If an instruction accesses a virtual address for which the relevant page
++table entry (PTE) has the Present bit cleared or other reserved bits set,
++then speculative execution ignores the invalid PTE and loads the referenced
++data if it is present in the Level 1 Data Cache, as if the page referenced
++by the address bits in the PTE was still present and accessible.
++
++While this is a purely speculative mechanism and the instruction will raise
++a page fault when it is retired eventually, the pure act of loading the
++data and making it available to other speculative instructions opens up the
++opportunity for side channel attacks to unprivileged malicious code,
++similar to the Meltdown attack.
++
++While Meltdown breaks the user space to kernel space protection, L1TF
++allows to attack any physical memory address in the system and the attack
++works across all protection domains. It allows an attack of SGX and also
++works from inside virtual machines because the speculation bypasses the
++extended page table (EPT) protection mechanism.
++
++
++Attack scenarios
++----------------
++
++1. Malicious user space
++^^^^^^^^^^^^^^^^^^^^^^^
++
++ Operating Systems store arbitrary information in the address bits of a
++ PTE which is marked non present. This allows a malicious user space
++ application to attack the physical memory to which these PTEs resolve.
++ In some cases user-space can maliciously influence the information
++ encoded in the address bits of the PTE, thus making attacks more
++ deterministic and more practical.
++
++ The Linux kernel contains a mitigation for this attack vector, PTE
++ inversion, which is permanently enabled and has no performance
++ impact. The kernel ensures that the address bits of PTEs, which are not
++ marked present, never point to cacheable physical memory space.
++
++ A system with an up to date kernel is protected against attacks from
++ malicious user space applications.
++
++2. Malicious guest in a virtual machine
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ The fact that L1TF breaks all domain protections allows malicious guest
++ OSes, which can control the PTEs directly, and malicious guest user
++ space applications, which run on an unprotected guest kernel lacking the
++ PTE inversion mitigation for L1TF, to attack physical host memory.
++
++ A special aspect of L1TF in the context of virtualization is symmetric
++ multi threading (SMT). The Intel implementation of SMT is called
++ HyperThreading. The fact that Hyperthreads on the affected processors
++ share the L1 Data Cache (L1D) is important for this. As the flaw allows
++ only to attack data which is present in L1D, a malicious guest running
++ on one Hyperthread can attack the data which is brought into the L1D by
++ the context which runs on the sibling Hyperthread of the same physical
++ core. This context can be host OS, host user space or a different guest.
++
++ If the processor does not support Extended Page Tables, the attack is
++ only possible, when the hypervisor does not sanitize the content of the
++ effective (shadow) page tables.
++
++ While solutions exist to mitigate these attack vectors fully, these
++ mitigations are not enabled by default in the Linux kernel because they
++ can affect performance significantly. The kernel provides several
++ mechanisms which can be utilized to address the problem depending on the
++ deployment scenario. The mitigations, their protection scope and impact
++ are described in the next sections.
++
++ The default mitigations and the rationale for choosing them are explained
++ at the end of this document. See :ref:`default_mitigations`.
++
++.. _l1tf_sys_info:
++
++L1TF system information
++-----------------------
++
++The Linux kernel provides a sysfs interface to enumerate the current L1TF
++status of the system: whether the system is vulnerable, and which
++mitigations are active. The relevant sysfs file is:
++
++/sys/devices/system/cpu/vulnerabilities/l1tf
++
++The possible values in this file are:
++
++ =========================== ===============================
++ 'Not affected' The processor is not vulnerable
++ 'Mitigation: PTE Inversion' The host protection is active
++ =========================== ===============================
++
++If KVM/VMX is enabled and the processor is vulnerable then the following
++information is appended to the 'Mitigation: PTE Inversion' part:
++
++ - SMT status:
++
++ ===================== ================
++ 'VMX: SMT vulnerable' SMT is enabled
++ 'VMX: SMT disabled' SMT is disabled
++ ===================== ================
++
++ - L1D Flush mode:
++
++ ================================ ====================================
++ 'L1D vulnerable' L1D flushing is disabled
++
++ 'L1D conditional cache flushes' L1D flush is conditionally enabled
++
++ 'L1D cache flushes' L1D flush is unconditionally enabled
++ ================================ ====================================
++
++The resulting grade of protection is discussed in the following sections.
++
++
++Host mitigation mechanism
++-------------------------
++
++The kernel is unconditionally protected against L1TF attacks from malicious
++user space running on the host.
++
++
++Guest mitigation mechanisms
++---------------------------
++
++.. _l1d_flush:
++
++1. L1D flush on VMENTER
++^^^^^^^^^^^^^^^^^^^^^^^
++
++ To make sure that a guest cannot attack data which is present in the L1D
++ the hypervisor flushes the L1D before entering the guest.
++
++ Flushing the L1D evicts not only the data which should not be accessed
++ by a potentially malicious guest, it also flushes the guest
++ data. Flushing the L1D has a performance impact as the processor has to
++ bring the flushed guest data back into the L1D. Depending on the
++ frequency of VMEXIT/VMENTER and the type of computations in the guest
++ performance degradation in the range of 1% to 50% has been observed. For
++ scenarios where guest VMEXIT/VMENTER are rare the performance impact is
++ minimal. Virtio and mechanisms like posted interrupts are designed to
++ confine the VMEXITs to a bare minimum, but specific configurations and
++ application scenarios might still suffer from a high VMEXIT rate.
++
++ The kernel provides two L1D flush modes:
++ - conditional ('cond')
++ - unconditional ('always')
++
++ The conditional mode avoids L1D flushing after VMEXITs which execute
++ only audited code paths before the corresponding VMENTER. These code
++ paths have been verified that they cannot expose secrets or other
++ interesting data to an attacker, but they can leak information about the
++ address space layout of the hypervisor.
++
++ Unconditional mode flushes L1D on all VMENTER invocations and provides
++ maximum protection. It has a higher overhead than the conditional
++ mode. The overhead cannot be quantified correctly as it depends on the
++ workload scenario and the resulting number of VMEXITs.
++
++ The general recommendation is to enable L1D flush on VMENTER. The kernel
++ defaults to conditional mode on affected processors.
++
++ **Note**, that L1D flush does not prevent the SMT problem because the
++ sibling thread will also bring back its data into the L1D which makes it
++ attackable again.
++
++ L1D flush can be controlled by the administrator via the kernel command
++ line and sysfs control files. See :ref:`mitigation_control_command_line`
++ and :ref:`mitigation_control_kvm`.
++
++.. _guest_confinement:
++
++2. Guest VCPU confinement to dedicated physical cores
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ To address the SMT problem, it is possible to make a guest or a group of
++ guests affine to one or more physical cores. The proper mechanism for
++ that is to utilize exclusive cpusets to ensure that no other guest or
++ host tasks can run on these cores.
++
++ If only a single guest or related guests run on sibling SMT threads on
++ the same physical core then they can only attack their own memory and
++ restricted parts of the host memory.
++
++ Host memory is attackable, when one of the sibling SMT threads runs in
++ host OS (hypervisor) context and the other in guest context. The amount
++ of valuable information from the host OS context depends on the context
++ which the host OS executes, i.e. interrupts, soft interrupts and kernel
++ threads. The amount of valuable data from these contexts cannot be
++ declared as non-interesting for an attacker without deep inspection of
++ the code.
++
++ **Note**, that assigning guests to a fixed set of physical cores affects
++ the ability of the scheduler to do load balancing and might have
++ negative effects on CPU utilization depending on the hosting
++ scenario. Disabling SMT might be a viable alternative for particular
++ scenarios.
++
++ For further information about confining guests to a single or to a group
++ of cores consult the cpusets documentation:
++
++ https://www.kernel.org/doc/Documentation/cgroup-v1/cpusets.txt
++
++.. _interrupt_isolation:
++
++3. Interrupt affinity
++^^^^^^^^^^^^^^^^^^^^^
++
++ Interrupts can be made affine to logical CPUs. This is not universally
++ true because there are types of interrupts which are truly per CPU
++ interrupts, e.g. the local timer interrupt. Aside of that multi queue
++ devices affine their interrupts to single CPUs or groups of CPUs per
++ queue without allowing the administrator to control the affinities.
++
++ Moving the interrupts, which can be affinity controlled, away from CPUs
++ which run untrusted guests, reduces the attack vector space.
++
++ Whether the interrupts with are affine to CPUs, which run untrusted
++ guests, provide interesting data for an attacker depends on the system
++ configuration and the scenarios which run on the system. While for some
++ of the interrupts it can be assumed that they won't expose interesting
++ information beyond exposing hints about the host OS memory layout, there
++ is no way to make general assumptions.
++
++ Interrupt affinity can be controlled by the administrator via the
++ /proc/irq/$NR/smp_affinity[_list] files. Limited documentation is
++ available at:
++
++ https://www.kernel.org/doc/Documentation/IRQ-affinity.txt
++
++.. _smt_control:
++
++4. SMT control
++^^^^^^^^^^^^^^
++
++ To prevent the SMT issues of L1TF it might be necessary to disable SMT
++ completely. Disabling SMT can have a significant performance impact, but
++ the impact depends on the hosting scenario and the type of workloads.
++ The impact of disabling SMT needs also to be weighted against the impact
++ of other mitigation solutions like confining guests to dedicated cores.
++
++ The kernel provides a sysfs interface to retrieve the status of SMT and
++ to control it. It also provides a kernel command line interface to
++ control SMT.
++
++ The kernel command line interface consists of the following options:
++
++ =========== ==========================================================
++ nosmt Affects the bring up of the secondary CPUs during boot. The
++ kernel tries to bring all present CPUs online during the
++ boot process. "nosmt" makes sure that from each physical
++ core only one - the so called primary (hyper) thread is
++ activated. Due to a design flaw of Intel processors related
++ to Machine Check Exceptions the non primary siblings have
++ to be brought up at least partially and are then shut down
++ again. "nosmt" can be undone via the sysfs interface.
++
++ nosmt=force Has the same effect as "nosmt" but it does not allow to
++ undo the SMT disable via the sysfs interface.
++ =========== ==========================================================
++
++ The sysfs interface provides two files:
++
++ - /sys/devices/system/cpu/smt/control
++ - /sys/devices/system/cpu/smt/active
++
++ /sys/devices/system/cpu/smt/control:
++
++ This file allows to read out the SMT control state and provides the
++ ability to disable or (re)enable SMT. The possible states are:
++
++ ============== ===================================================
++ on SMT is supported by the CPU and enabled. All
++ logical CPUs can be onlined and offlined without
++ restrictions.
++
++ off SMT is supported by the CPU and disabled. Only
++ the so called primary SMT threads can be onlined
++ and offlined without restrictions. An attempt to
++ online a non-primary sibling is rejected
++
++ forceoff Same as 'off' but the state cannot be controlled.
++ Attempts to write to the control file are rejected.
++
++ notsupported The processor does not support SMT. It's therefore
++ not affected by the SMT implications of L1TF.
++ Attempts to write to the control file are rejected.
++ ============== ===================================================
++
++ The possible states which can be written into this file to control SMT
++ state are:
++
++ - on
++ - off
++ - forceoff
++
++ /sys/devices/system/cpu/smt/active:
++
++ This file reports whether SMT is enabled and active, i.e. if on any
++ physical core two or more sibling threads are online.
++
++ SMT control is also possible at boot time via the l1tf kernel command
++ line parameter in combination with L1D flush control. See
++ :ref:`mitigation_control_command_line`.
++
++5. Disabling EPT
++^^^^^^^^^^^^^^^^
++
++ Disabling EPT for virtual machines provides full mitigation for L1TF even
++ with SMT enabled, because the effective page tables for guests are
++ managed and sanitized by the hypervisor. Though disabling EPT has a
++ significant performance impact especially when the Meltdown mitigation
++ KPTI is enabled.
++
++ EPT can be disabled in the hypervisor via the 'kvm-intel.ept' parameter.
++
++There is ongoing research and development for new mitigation mechanisms to
++address the performance impact of disabling SMT or EPT.
++
++.. _mitigation_control_command_line:
++
++Mitigation control on the kernel command line
++---------------------------------------------
++
++The kernel command line allows to control the L1TF mitigations at boot
++time with the option "l1tf=". The valid arguments for this option are:
++
++ ============ =============================================================
++ full Provides all available mitigations for the L1TF
++ vulnerability. Disables SMT and enables all mitigations in
++ the hypervisors, i.e. unconditional L1D flushing
++
++ SMT control and L1D flush control via the sysfs interface
++ is still possible after boot. Hypervisors will issue a
++ warning when the first VM is started in a potentially
++ insecure configuration, i.e. SMT enabled or L1D flush
++ disabled.
++
++ full,force Same as 'full', but disables SMT and L1D flush runtime
++ control. Implies the 'nosmt=force' command line option.
++ (i.e. sysfs control of SMT is disabled.)
++
++ flush Leaves SMT enabled and enables the default hypervisor
++ mitigation, i.e. conditional L1D flushing
++
++ SMT control and L1D flush control via the sysfs interface
++ is still possible after boot. Hypervisors will issue a
++ warning when the first VM is started in a potentially
++ insecure configuration, i.e. SMT enabled or L1D flush
++ disabled.
++
++ flush,nosmt Disables SMT and enables the default hypervisor mitigation,
++ i.e. conditional L1D flushing.
++
++ SMT control and L1D flush control via the sysfs interface
++ is still possible after boot. Hypervisors will issue a
++ warning when the first VM is started in a potentially
++ insecure configuration, i.e. SMT enabled or L1D flush
++ disabled.
++
++ flush,nowarn Same as 'flush', but hypervisors will not warn when a VM is
++ started in a potentially insecure configuration.
++
++ off Disables hypervisor mitigations and doesn't emit any
++ warnings.
++ ============ =============================================================
++
++The default is 'flush'. For details about L1D flushing see :ref:`l1d_flush`.
++
++
++.. _mitigation_control_kvm:
++
++Mitigation control for KVM - module parameter
++-------------------------------------------------------------
++
++The KVM hypervisor mitigation mechanism, flushing the L1D cache when
++entering a guest, can be controlled with a module parameter.
++
++The option/parameter is "kvm-intel.vmentry_l1d_flush=". It takes the
++following arguments:
++
++ ============ ==============================================================
++ always L1D cache flush on every VMENTER.
++
++ cond Flush L1D on VMENTER only when the code between VMEXIT and
++ VMENTER can leak host memory which is considered
++ interesting for an attacker. This still can leak host memory
++ which allows e.g. to determine the hosts address space layout.
++
++ never Disables the mitigation
++ ============ ==============================================================
++
++The parameter can be provided on the kernel command line, as a module
++parameter when loading the modules and at runtime modified via the sysfs
++file:
++
++/sys/module/kvm_intel/parameters/vmentry_l1d_flush
++
++The default is 'cond'. If 'l1tf=full,force' is given on the kernel command
++line, then 'always' is enforced and the kvm-intel.vmentry_l1d_flush
++module parameter is ignored and writes to the sysfs file are rejected.
++
++
++Mitigation selection guide
++--------------------------
++
++1. No virtualization in use
++^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ The system is protected by the kernel unconditionally and no further
++ action is required.
++
++2. Virtualization with trusted guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ If the guest comes from a trusted source and the guest OS kernel is
++ guaranteed to have the L1TF mitigations in place the system is fully
++ protected against L1TF and no further action is required.
++
++ To avoid the overhead of the default L1D flushing on VMENTER the
++ administrator can disable the flushing via the kernel command line and
++ sysfs control files. See :ref:`mitigation_control_command_line` and
++ :ref:`mitigation_control_kvm`.
++
++
++3. Virtualization with untrusted guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++3.1. SMT not supported or disabled
++""""""""""""""""""""""""""""""""""
++
++ If SMT is not supported by the processor or disabled in the BIOS or by
++ the kernel, it's only required to enforce L1D flushing on VMENTER.
++
++ Conditional L1D flushing is the default behaviour and can be tuned. See
++ :ref:`mitigation_control_command_line` and :ref:`mitigation_control_kvm`.
++
++3.2. EPT not supported or disabled
++""""""""""""""""""""""""""""""""""
++
++ If EPT is not supported by the processor or disabled in the hypervisor,
++ the system is fully protected. SMT can stay enabled and L1D flushing on
++ VMENTER is not required.
++
++ EPT can be disabled in the hypervisor via the 'kvm-intel.ept' parameter.
++
++3.3. SMT and EPT supported and active
++"""""""""""""""""""""""""""""""""""""
++
++ If SMT and EPT are supported and active then various degrees of
++ mitigations can be employed:
++
++ - L1D flushing on VMENTER:
++
++ L1D flushing on VMENTER is the minimal protection requirement, but it
++ is only potent in combination with other mitigation methods.
++
++ Conditional L1D flushing is the default behaviour and can be tuned. See
++ :ref:`mitigation_control_command_line` and :ref:`mitigation_control_kvm`.
++
++ - Guest confinement:
++
++ Confinement of guests to a single or a group of physical cores which
++ are not running any other processes, can reduce the attack surface
++ significantly, but interrupts, soft interrupts and kernel threads can
++ still expose valuable data to a potential attacker. See
++ :ref:`guest_confinement`.
++
++ - Interrupt isolation:
++
++ Isolating the guest CPUs from interrupts can reduce the attack surface
++ further, but still allows a malicious guest to explore a limited amount
++ of host physical memory. This can at least be used to gain knowledge
++ about the host address space layout. The interrupts which have a fixed
++ affinity to the CPUs which run the untrusted guests can depending on
++ the scenario still trigger soft interrupts and schedule kernel threads
++ which might expose valuable information. See
++ :ref:`interrupt_isolation`.
++
++The above three mitigation methods combined can provide protection to a
++certain degree, but the risk of the remaining attack surface has to be
++carefully analyzed. For full protection the following methods are
++available:
++
++ - Disabling SMT:
++
++ Disabling SMT and enforcing the L1D flushing provides the maximum
++ amount of protection. This mitigation is not depending on any of the
++ above mitigation methods.
++
++ SMT control and L1D flushing can be tuned by the command line
++ parameters 'nosmt', 'l1tf', 'kvm-intel.vmentry_l1d_flush' and at run
++ time with the matching sysfs control files. See :ref:`smt_control`,
++ :ref:`mitigation_control_command_line` and
++ :ref:`mitigation_control_kvm`.
++
++ - Disabling EPT:
++
++ Disabling EPT provides the maximum amount of protection as well. It is
++ not depending on any of the above mitigation methods. SMT can stay
++ enabled and L1D flushing is not required, but the performance impact is
++ significant.
++
++ EPT can be disabled in the hypervisor via the 'kvm-intel.ept'
++ parameter.
++
++3.4. Nested virtual machines
++""""""""""""""""""""""""""""
++
++When nested virtualization is in use, three operating systems are involved:
++the bare metal hypervisor, the nested hypervisor and the nested virtual
++machine. VMENTER operations from the nested hypervisor into the nested
++guest will always be processed by the bare metal hypervisor. If KVM is the
++bare metal hypervisor it wiil:
++
++ - Flush the L1D cache on every switch from the nested hypervisor to the
++ nested virtual machine, so that the nested hypervisor's secrets are not
++ exposed to the nested virtual machine;
++
++ - Flush the L1D cache on every switch from the nested virtual machine to
++ the nested hypervisor; this is a complex operation, and flushing the L1D
++ cache avoids that the bare metal hypervisor's secrets are exposed to the
++ nested virtual machine;
++
++ - Instruct the nested hypervisor to not perform any L1D cache flush. This
++ is an optimization to avoid double L1D flushing.
++
++
++.. _default_mitigations:
++
++Default mitigations
++-------------------
++
++ The kernel default mitigations for vulnerable processors are:
++
++ - PTE inversion to protect against malicious user space. This is done
++ unconditionally and cannot be controlled.
++
++ - L1D conditional flushing on VMENTER when EPT is enabled for
++ a guest.
++
++ The kernel does not by default enforce the disabling of SMT, which leaves
++ SMT systems vulnerable when running untrusted guests with EPT enabled.
++
++ The rationale for this choice is:
++
++ - Force disabling SMT can break existing setups, especially with
++ unattended updates.
++
++ - If regular users run untrusted guests on their machine, then L1TF is
++ just an add on to other malware which might be embedded in an untrusted
++ guest, e.g. spam-bots or attacks on the local network.
++
++ There is no technical way to prevent a user from running untrusted code
++ on their machines blindly.
++
++ - It's technically extremely unlikely and from today's knowledge even
++ impossible that L1TF can be exploited via the most popular attack
++ mechanisms like JavaScript because these mechanisms have no way to
++ control PTEs. If this would be possible and not other mitigation would
++ be possible, then the default might be different.
++
++ - The administrators of cloud and hosting setups have to carefully
++ analyze the risk for their scenarios and make the appropriate
++ mitigation choices, which might even vary across their deployed
++ machines and also result in other changes of their overall setup.
++ There is no way for the kernel to provide a sensible default for this
++ kind of scenarios.
+diff --git a/Makefile b/Makefile
+index 863f58503bee..5edf963148e8 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1,7 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0
+ VERSION = 4
+ PATCHLEVEL = 18
+-SUBLEVEL = 0
++SUBLEVEL = 1
+ EXTRAVERSION =
+ NAME = Merciless Moray
+
+diff --git a/arch/Kconfig b/arch/Kconfig
+index 1aa59063f1fd..d1f2ed462ac8 100644
+--- a/arch/Kconfig
++++ b/arch/Kconfig
+@@ -13,6 +13,9 @@ config KEXEC_CORE
+ config HAVE_IMA_KEXEC
+ bool
+
++config HOTPLUG_SMT
++ bool
++
+ config OPROFILE
+ tristate "OProfile system profiling"
+ depends on PROFILING
+diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
+index 887d3a7bb646..6b8065d718bd 100644
+--- a/arch/x86/Kconfig
++++ b/arch/x86/Kconfig
+@@ -187,6 +187,7 @@ config X86
+ select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UNSTABLE_SCHED_CLOCK
+ select HAVE_USER_RETURN_NOTIFIER
++ select HOTPLUG_SMT if SMP
+ select IRQ_FORCED_THREADING
+ select NEED_SG_DMA_LENGTH
+ select PCI_LOCKLESS_CONFIG
+diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
+index 74a9e06b6cfd..130e81e10fc7 100644
+--- a/arch/x86/include/asm/apic.h
++++ b/arch/x86/include/asm/apic.h
+@@ -10,6 +10,7 @@
+ #include <asm/fixmap.h>
+ #include <asm/mpspec.h>
+ #include <asm/msr.h>
++#include <asm/hardirq.h>
+
+ #define ARCH_APICTIMER_STOPS_ON_C3 1
+
+@@ -502,12 +503,19 @@ extern int default_check_phys_apicid_present(int phys_apicid);
+
+ #endif /* CONFIG_X86_LOCAL_APIC */
+
++#ifdef CONFIG_SMP
++bool apic_id_is_primary_thread(unsigned int id);
++#else
++static inline bool apic_id_is_primary_thread(unsigned int id) { return false; }
++#endif
++
+ extern void irq_enter(void);
+ extern void irq_exit(void);
+
+ static inline void entering_irq(void)
+ {
+ irq_enter();
++ kvm_set_cpu_l1tf_flush_l1d();
+ }
+
+ static inline void entering_ack_irq(void)
+@@ -520,6 +528,7 @@ static inline void ipi_entering_ack_irq(void)
+ {
+ irq_enter();
+ ack_APIC_irq();
++ kvm_set_cpu_l1tf_flush_l1d();
+ }
+
+ static inline void exiting_irq(void)
+diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
+index 5701f5cecd31..64aaa3f5f36c 100644
+--- a/arch/x86/include/asm/cpufeatures.h
++++ b/arch/x86/include/asm/cpufeatures.h
+@@ -219,6 +219,7 @@
+ #define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */
+ #define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */
+ #define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
++#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
+
+ /* Virtualization flags: Linux defined, word 8 */
+ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
+@@ -341,6 +342,7 @@
+ #define X86_FEATURE_PCONFIG (18*32+18) /* Intel PCONFIG */
+ #define X86_FEATURE_SPEC_CTRL (18*32+26) /* "" Speculation Control (IBRS + IBPB) */
+ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */
++#define X86_FEATURE_FLUSH_L1D (18*32+28) /* Flush L1D cache */
+ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
+ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */
+
+@@ -373,5 +375,6 @@
+ #define X86_BUG_SPECTRE_V1 X86_BUG(15) /* CPU is affected by Spectre variant 1 attack with conditional branches */
+ #define X86_BUG_SPECTRE_V2 X86_BUG(16) /* CPU is affected by Spectre variant 2 attack with indirect branches */
+ #define X86_BUG_SPEC_STORE_BYPASS X86_BUG(17) /* CPU is affected by speculative store bypass attack */
++#define X86_BUG_L1TF X86_BUG(18) /* CPU is affected by L1 Terminal Fault */
+
+ #endif /* _ASM_X86_CPUFEATURES_H */
+diff --git a/arch/x86/include/asm/dmi.h b/arch/x86/include/asm/dmi.h
+index 0ab2ab27ad1f..b825cb201251 100644
+--- a/arch/x86/include/asm/dmi.h
++++ b/arch/x86/include/asm/dmi.h
+@@ -4,8 +4,8 @@
+
+ #include <linux/compiler.h>
+ #include <linux/init.h>
++#include <linux/io.h>
+
+-#include <asm/io.h>
+ #include <asm/setup.h>
+
+ static __always_inline __init void *dmi_alloc(unsigned len)
+diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
+index 740a428acf1e..d9069bb26c7f 100644
+--- a/arch/x86/include/asm/hardirq.h
++++ b/arch/x86/include/asm/hardirq.h
+@@ -3,10 +3,12 @@
+ #define _ASM_X86_HARDIRQ_H
+
+ #include <linux/threads.h>
+-#include <linux/irq.h>
+
+ typedef struct {
+- unsigned int __softirq_pending;
++ u16 __softirq_pending;
++#if IS_ENABLED(CONFIG_KVM_INTEL)
++ u8 kvm_cpu_l1tf_flush_l1d;
++#endif
+ unsigned int __nmi_count; /* arch dependent */
+ #ifdef CONFIG_X86_LOCAL_APIC
+ unsigned int apic_timer_irqs; /* arch dependent */
+@@ -58,4 +60,24 @@ extern u64 arch_irq_stat_cpu(unsigned int cpu);
+ extern u64 arch_irq_stat(void);
+ #define arch_irq_stat arch_irq_stat
+
++
++#if IS_ENABLED(CONFIG_KVM_INTEL)
++static inline void kvm_set_cpu_l1tf_flush_l1d(void)
++{
++ __this_cpu_write(irq_stat.kvm_cpu_l1tf_flush_l1d, 1);
++}
++
++static inline void kvm_clear_cpu_l1tf_flush_l1d(void)
++{
++ __this_cpu_write(irq_stat.kvm_cpu_l1tf_flush_l1d, 0);
++}
++
++static inline bool kvm_get_cpu_l1tf_flush_l1d(void)
++{
++ return __this_cpu_read(irq_stat.kvm_cpu_l1tf_flush_l1d);
++}
++#else /* !IS_ENABLED(CONFIG_KVM_INTEL) */
++static inline void kvm_set_cpu_l1tf_flush_l1d(void) { }
++#endif /* IS_ENABLED(CONFIG_KVM_INTEL) */
++
+ #endif /* _ASM_X86_HARDIRQ_H */
+diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
+index c4fc17220df9..c14f2a74b2be 100644
+--- a/arch/x86/include/asm/irqflags.h
++++ b/arch/x86/include/asm/irqflags.h
+@@ -13,6 +13,8 @@
+ * Interrupt control:
+ */
+
++/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
++extern inline unsigned long native_save_fl(void);
+ extern inline unsigned long native_save_fl(void)
+ {
+ unsigned long flags;
+diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
+index c13cd28d9d1b..acebb808c4b5 100644
+--- a/arch/x86/include/asm/kvm_host.h
++++ b/arch/x86/include/asm/kvm_host.h
+@@ -17,6 +17,7 @@
+ #include <linux/tracepoint.h>
+ #include <linux/cpumask.h>
+ #include <linux/irq_work.h>
++#include <linux/irq.h>
+
+ #include <linux/kvm.h>
+ #include <linux/kvm_para.h>
+@@ -713,6 +714,9 @@ struct kvm_vcpu_arch {
+
+ /* be preempted when it's in kernel-mode(cpl=0) */
+ bool preempted_in_kernel;
++
++ /* Flush the L1 Data cache for L1TF mitigation on VMENTER */
++ bool l1tf_flush_l1d;
+ };
+
+ struct kvm_lpage_info {
+@@ -881,6 +885,7 @@ struct kvm_vcpu_stat {
+ u64 signal_exits;
+ u64 irq_window_exits;
+ u64 nmi_window_exits;
++ u64 l1d_flush;
+ u64 halt_exits;
+ u64 halt_successful_poll;
+ u64 halt_attempted_poll;
+@@ -1413,6 +1418,7 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
+ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
+ void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
+
++u64 kvm_get_arch_capabilities(void);
+ void kvm_define_shared_msr(unsigned index, u32 msr);
+ int kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
+
+diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
+index 68b2c3150de1..4731f0cf97c5 100644
+--- a/arch/x86/include/asm/msr-index.h
++++ b/arch/x86/include/asm/msr-index.h
+@@ -70,12 +70,19 @@
+ #define MSR_IA32_ARCH_CAPABILITIES 0x0000010a
+ #define ARCH_CAP_RDCL_NO (1 << 0) /* Not susceptible to Meltdown */
+ #define ARCH_CAP_IBRS_ALL (1 << 1) /* Enhanced IBRS support */
++#define ARCH_CAP_SKIP_VMENTRY_L1DFLUSH (1 << 3) /* Skip L1D flush on vmentry */
+ #define ARCH_CAP_SSB_NO (1 << 4) /*
+ * Not susceptible to Speculative Store Bypass
+ * attack, so no Speculative Store Bypass
+ * control required.
+ */
+
++#define MSR_IA32_FLUSH_CMD 0x0000010b
++#define L1D_FLUSH (1 << 0) /*
++ * Writeback and invalidate the
++ * L1 data cache.
++ */
++
+ #define MSR_IA32_BBL_CR_CTL 0x00000119
+ #define MSR_IA32_BBL_CR_CTL3 0x0000011e
+
+diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
+index aa30c3241ea7..0d5c739eebd7 100644
+--- a/arch/x86/include/asm/page_32_types.h
++++ b/arch/x86/include/asm/page_32_types.h
+@@ -29,8 +29,13 @@
+ #define N_EXCEPTION_STACKS 1
+
+ #ifdef CONFIG_X86_PAE
+-/* 44=32+12, the limit we can fit into an unsigned long pfn */
+-#define __PHYSICAL_MASK_SHIFT 44
++/*
++ * This is beyond the 44 bit limit imposed by the 32bit long pfns,
++ * but we need the full mask to make sure inverted PROT_NONE
++ * entries have all the host bits set in a guest.
++ * The real limit is still 44 bits.
++ */
++#define __PHYSICAL_MASK_SHIFT 52
+ #define __VIRTUAL_MASK_SHIFT 32
+
+ #else /* !CONFIG_X86_PAE */
+diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
+index 685ffe8a0eaf..60d0f9015317 100644
+--- a/arch/x86/include/asm/pgtable-2level.h
++++ b/arch/x86/include/asm/pgtable-2level.h
+@@ -95,4 +95,21 @@ static inline unsigned long pte_bitop(unsigned long value, unsigned int rightshi
+ #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_low })
+ #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val })
+
++/* No inverted PFNs on 2 level page tables */
++
++static inline u64 protnone_mask(u64 val)
++{
++ return 0;
++}
++
++static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask)
++{
++ return val;
++}
++
++static inline bool __pte_needs_invert(u64 val)
++{
++ return false;
++}
++
+ #endif /* _ASM_X86_PGTABLE_2LEVEL_H */
+diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
+index f24df59c40b2..bb035a4cbc8c 100644
+--- a/arch/x86/include/asm/pgtable-3level.h
++++ b/arch/x86/include/asm/pgtable-3level.h
+@@ -241,12 +241,43 @@ static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
+ #endif
+
+ /* Encode and de-code a swap entry */
++#define SWP_TYPE_BITS 5
++
++#define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
++
++/* We always extract/encode the offset by shifting it all the way up, and then down again */
++#define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT + SWP_TYPE_BITS)
++
+ #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
+ #define __swp_type(x) (((x).val) & 0x1f)
+ #define __swp_offset(x) ((x).val >> 5)
+ #define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << 5})
+-#define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high })
+-#define __swp_entry_to_pte(x) ((pte_t){ { .pte_high = (x).val } })
++
++/*
++ * Normally, __swp_entry() converts from arch-independent swp_entry_t to
++ * arch-dependent swp_entry_t, and __swp_entry_to_pte() just stores the result
++ * to pte. But here we have 32bit swp_entry_t and 64bit pte, and need to use the
++ * whole 64 bits. Thus, we shift the "real" arch-dependent conversion to
++ * __swp_entry_to_pte() through the following helper macro based on 64bit
++ * __swp_entry().
++ */
++#define __swp_pteval_entry(type, offset) ((pteval_t) { \
++ (~(pteval_t)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
++ | ((pteval_t)(type) << (64 - SWP_TYPE_BITS)) })
++
++#define __swp_entry_to_pte(x) ((pte_t){ .pte = \
++ __swp_pteval_entry(__swp_type(x), __swp_offset(x)) })
++/*
++ * Analogically, __pte_to_swp_entry() doesn't just extract the arch-dependent
++ * swp_entry_t, but also has to convert it from 64bit to the 32bit
++ * intermediate representation, using the following macros based on 64bit
++ * __swp_type() and __swp_offset().
++ */
++#define __pteval_swp_type(x) ((unsigned long)((x).pte >> (64 - SWP_TYPE_BITS)))
++#define __pteval_swp_offset(x) ((unsigned long)(~((x).pte) << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT))
++
++#define __pte_to_swp_entry(pte) (__swp_entry(__pteval_swp_type(pte), \
++ __pteval_swp_offset(pte)))
+
+ #define gup_get_pte gup_get_pte
+ /*
+@@ -295,4 +326,6 @@ static inline pte_t gup_get_pte(pte_t *ptep)
+ return pte;
+ }
+
++#include <asm/pgtable-invert.h>
++
+ #endif /* _ASM_X86_PGTABLE_3LEVEL_H */
+diff --git a/arch/x86/include/asm/pgtable-invert.h b/arch/x86/include/asm/pgtable-invert.h
+new file mode 100644
+index 000000000000..44b1203ece12
+--- /dev/null
++++ b/arch/x86/include/asm/pgtable-invert.h
+@@ -0,0 +1,32 @@
++/* SPDX-License-Identifier: GPL-2.0 */
++#ifndef _ASM_PGTABLE_INVERT_H
++#define _ASM_PGTABLE_INVERT_H 1
++
++#ifndef __ASSEMBLY__
++
++static inline bool __pte_needs_invert(u64 val)
++{
++ return !(val & _PAGE_PRESENT);
++}
++
++/* Get a mask to xor with the page table entry to get the correct pfn. */
++static inline u64 protnone_mask(u64 val)
++{
++ return __pte_needs_invert(val) ? ~0ull : 0;
++}
++
++static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask)
++{
++ /*
++ * When a PTE transitions from NONE to !NONE or vice-versa
++ * invert the PFN part to stop speculation.
++ * pte_pfn undoes this when needed.
++ */
++ if (__pte_needs_invert(oldval) != __pte_needs_invert(val))
++ val = (val & ~mask) | (~val & mask);
++ return val;
++}
++
++#endif /* __ASSEMBLY__ */
++
++#endif
+diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
+index 5715647fc4fe..13125aad804c 100644
+--- a/arch/x86/include/asm/pgtable.h
++++ b/arch/x86/include/asm/pgtable.h
+@@ -185,19 +185,29 @@ static inline int pte_special(pte_t pte)
+ return pte_flags(pte) & _PAGE_SPECIAL;
+ }
+
++/* Entries that were set to PROT_NONE are inverted */
++
++static inline u64 protnone_mask(u64 val);
++
+ static inline unsigned long pte_pfn(pte_t pte)
+ {
+- return (pte_val(pte) & PTE_PFN_MASK) >> PAGE_SHIFT;
++ phys_addr_t pfn = pte_val(pte);
++ pfn ^= protnone_mask(pfn);
++ return (pfn & PTE_PFN_MASK) >> PAGE_SHIFT;
+ }
+
+ static inline unsigned long pmd_pfn(pmd_t pmd)
+ {
+- return (pmd_val(pmd) & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
++ phys_addr_t pfn = pmd_val(pmd);
++ pfn ^= protnone_mask(pfn);
++ return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
+ }
+
+ static inline unsigned long pud_pfn(pud_t pud)
+ {
+- return (pud_val(pud) & pud_pfn_mask(pud)) >> PAGE_SHIFT;
++ phys_addr_t pfn = pud_val(pud);
++ pfn ^= protnone_mask(pfn);
++ return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
+ }
+
+ static inline unsigned long p4d_pfn(p4d_t p4d)
+@@ -400,11 +410,6 @@ static inline pmd_t pmd_mkwrite(pmd_t pmd)
+ return pmd_set_flags(pmd, _PAGE_RW);
+ }
+
+-static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+-{
+- return pmd_clear_flags(pmd, _PAGE_PRESENT | _PAGE_PROTNONE);
+-}
+-
+ static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
+ {
+ pudval_t v = native_pud_val(pud);
+@@ -459,11 +464,6 @@ static inline pud_t pud_mkwrite(pud_t pud)
+ return pud_set_flags(pud, _PAGE_RW);
+ }
+
+-static inline pud_t pud_mknotpresent(pud_t pud)
+-{
+- return pud_clear_flags(pud, _PAGE_PRESENT | _PAGE_PROTNONE);
+-}
+-
+ #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
+ static inline int pte_soft_dirty(pte_t pte)
+ {
+@@ -545,25 +545,45 @@ static inline pgprotval_t check_pgprot(pgprot_t pgprot)
+
+ static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
+ {
+- return __pte(((phys_addr_t)page_nr << PAGE_SHIFT) |
+- check_pgprot(pgprot));
++ phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
++ pfn ^= protnone_mask(pgprot_val(pgprot));
++ pfn &= PTE_PFN_MASK;
++ return __pte(pfn | check_pgprot(pgprot));
+ }
+
+ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
+ {
+- return __pmd(((phys_addr_t)page_nr << PAGE_SHIFT) |
+- check_pgprot(pgprot));
++ phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
++ pfn ^= protnone_mask(pgprot_val(pgprot));
++ pfn &= PHYSICAL_PMD_PAGE_MASK;
++ return __pmd(pfn | check_pgprot(pgprot));
+ }
+
+ static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
+ {
+- return __pud(((phys_addr_t)page_nr << PAGE_SHIFT) |
+- check_pgprot(pgprot));
++ phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
++ pfn ^= protnone_mask(pgprot_val(pgprot));
++ pfn &= PHYSICAL_PUD_PAGE_MASK;
++ return __pud(pfn | check_pgprot(pgprot));
+ }
+
++static inline pmd_t pmd_mknotpresent(pmd_t pmd)
++{
++ return pfn_pmd(pmd_pfn(pmd),
++ __pgprot(pmd_flags(pmd) & ~(_PAGE_PRESENT|_PAGE_PROTNONE)));
++}
++
++static inline pud_t pud_mknotpresent(pud_t pud)
++{
++ return pfn_pud(pud_pfn(pud),
++ __pgprot(pud_flags(pud) & ~(_PAGE_PRESENT|_PAGE_PROTNONE)));
++}
++
++static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask);
++
+ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+ {
+- pteval_t val = pte_val(pte);
++ pteval_t val = pte_val(pte), oldval = val;
+
+ /*
+ * Chop off the NX bit (if present), and add the NX portion of
+@@ -571,17 +591,17 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+ */
+ val &= _PAGE_CHG_MASK;
+ val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK;
+-
++ val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
+ return __pte(val);
+ }
+
+ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+ {
+- pmdval_t val = pmd_val(pmd);
++ pmdval_t val = pmd_val(pmd), oldval = val;
+
+ val &= _HPAGE_CHG_MASK;
+ val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK;
+-
++ val = flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK);
+ return __pmd(val);
+ }
+
+@@ -1320,6 +1340,14 @@ static inline bool pud_access_permitted(pud_t pud, bool write)
+ return __pte_access_permitted(pud_val(pud), write);
+ }
+
++#define __HAVE_ARCH_PFN_MODIFY_ALLOWED 1
++extern bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot);
++
++static inline bool arch_has_pfn_modify_check(void)
++{
++ return boot_cpu_has_bug(X86_BUG_L1TF);
++}
++
+ #include <asm-generic/pgtable.h>
+ #endif /* __ASSEMBLY__ */
+
+diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
+index 3c5385f9a88f..82ff20b0ae45 100644
+--- a/arch/x86/include/asm/pgtable_64.h
++++ b/arch/x86/include/asm/pgtable_64.h
+@@ -273,7 +273,7 @@ static inline int pgd_large(pgd_t pgd) { return 0; }
+ *
+ * | ... | 11| 10| 9|8|7|6|5| 4| 3|2| 1|0| <- bit number
+ * | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
+- * | OFFSET (14->63) | TYPE (9-13) |0|0|X|X| X| X|X|SD|0| <- swp entry
++ * | TYPE (59-63) | ~OFFSET (9-58) |0|0|X|X| X| X|X|SD|0| <- swp entry
+ *
+ * G (8) is aliased and used as a PROT_NONE indicator for
+ * !present ptes. We need to start storing swap entries above
+@@ -286,20 +286,34 @@ static inline int pgd_large(pgd_t pgd) { return 0; }
+ *
+ * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
+ * but also L and G.
++ *
++ * The offset is inverted by a binary not operation to make the high
++ * physical bits set.
+ */
+-#define SWP_TYPE_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
+-#define SWP_TYPE_BITS 5
+-/* Place the offset above the type: */
+-#define SWP_OFFSET_FIRST_BIT (SWP_TYPE_FIRST_BIT + SWP_TYPE_BITS)
++#define SWP_TYPE_BITS 5
++
++#define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
++
++/* We always extract/encode the offset by shifting it all the way up, and then down again */
++#define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
+
+ #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
+
+-#define __swp_type(x) (((x).val >> (SWP_TYPE_FIRST_BIT)) \
+- & ((1U << SWP_TYPE_BITS) - 1))
+-#define __swp_offset(x) ((x).val >> SWP_OFFSET_FIRST_BIT)
+-#define __swp_entry(type, offset) ((swp_entry_t) { \
+- ((type) << (SWP_TYPE_FIRST_BIT)) \
+- | ((offset) << SWP_OFFSET_FIRST_BIT) })
++/* Extract the high bits for type */
++#define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
++
++/* Shift up (to get rid of type), then down to get value */
++#define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
++
++/*
++ * Shift the offset up "too far" by TYPE bits, then down again
++ * The offset is inverted by a binary not operation to make the high
++ * physical bits set.
++ */
++#define __swp_entry(type, offset) ((swp_entry_t) { \
++ (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
++ | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
++
+ #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) })
+ #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val((pmd)) })
+ #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val })
+@@ -343,5 +357,7 @@ static inline bool gup_fast_permitted(unsigned long start, int nr_pages,
+ return true;
+ }
+
++#include <asm/pgtable-invert.h>
++
+ #endif /* !__ASSEMBLY__ */
+ #endif /* _ASM_X86_PGTABLE_64_H */
+diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
+index cfd29ee8c3da..79e409974ccc 100644
+--- a/arch/x86/include/asm/processor.h
++++ b/arch/x86/include/asm/processor.h
+@@ -181,6 +181,11 @@ extern const struct seq_operations cpuinfo_op;
+
+ extern void cpu_detect(struct cpuinfo_x86 *c);
+
++static inline unsigned long l1tf_pfn_limit(void)
++{
++ return BIT(boot_cpu_data.x86_phys_bits - 1 - PAGE_SHIFT) - 1;
++}
++
+ extern void early_cpu_init(void);
+ extern void identify_boot_cpu(void);
+ extern void identify_secondary_cpu(struct cpuinfo_x86 *);
+@@ -977,4 +982,16 @@ bool xen_set_default_idle(void);
+ void stop_this_cpu(void *dummy);
+ void df_debug(struct pt_regs *regs, long error_code);
+ void microcode_check(void);
++
++enum l1tf_mitigations {
++ L1TF_MITIGATION_OFF,
++ L1TF_MITIGATION_FLUSH_NOWARN,
++ L1TF_MITIGATION_FLUSH,
++ L1TF_MITIGATION_FLUSH_NOSMT,
++ L1TF_MITIGATION_FULL,
++ L1TF_MITIGATION_FULL_FORCE
++};
++
++extern enum l1tf_mitigations l1tf_mitigation;
++
+ #endif /* _ASM_X86_PROCESSOR_H */
+diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
+index c1d2a9892352..453cf38a1c33 100644
+--- a/arch/x86/include/asm/topology.h
++++ b/arch/x86/include/asm/topology.h
+@@ -123,13 +123,17 @@ static inline int topology_max_smt_threads(void)
+ }
+
+ int topology_update_package_map(unsigned int apicid, unsigned int cpu);
+-extern int topology_phys_to_logical_pkg(unsigned int pkg);
++int topology_phys_to_logical_pkg(unsigned int pkg);
++bool topology_is_primary_thread(unsigned int cpu);
++bool topology_smt_supported(void);
+ #else
+ #define topology_max_packages() (1)
+ static inline int
+ topology_update_package_map(unsigned int apicid, unsigned int cpu) { return 0; }
+ static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return 0; }
+ static inline int topology_max_smt_threads(void) { return 1; }
++static inline bool topology_is_primary_thread(unsigned int cpu) { return true; }
++static inline bool topology_smt_supported(void) { return false; }
+ #endif
+
+ static inline void arch_fix_phys_package_id(int num, u32 slot)
+diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
+index 6aa8499e1f62..95f9107449bf 100644
+--- a/arch/x86/include/asm/vmx.h
++++ b/arch/x86/include/asm/vmx.h
+@@ -576,4 +576,15 @@ enum vm_instruction_error_number {
+ VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID = 28,
+ };
+
++enum vmx_l1d_flush_state {
++ VMENTER_L1D_FLUSH_AUTO,
++ VMENTER_L1D_FLUSH_NEVER,
++ VMENTER_L1D_FLUSH_COND,
++ VMENTER_L1D_FLUSH_ALWAYS,
++ VMENTER_L1D_FLUSH_EPT_DISABLED,
++ VMENTER_L1D_FLUSH_NOT_REQUIRED,
++};
++
++extern enum vmx_l1d_flush_state l1tf_vmx_mitigation;
++
+ #endif
+diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
+index adbda5847b14..3b3a2d0af78d 100644
+--- a/arch/x86/kernel/apic/apic.c
++++ b/arch/x86/kernel/apic/apic.c
+@@ -56,6 +56,7 @@
+ #include <asm/hypervisor.h>
+ #include <asm/cpu_device_id.h>
+ #include <asm/intel-family.h>
++#include <asm/irq_regs.h>
+
+ unsigned int num_processors;
+
+@@ -2192,6 +2193,23 @@ static int cpuid_to_apicid[] = {
+ [0 ... NR_CPUS - 1] = -1,
+ };
+
++#ifdef CONFIG_SMP
++/**
++ * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
++ * @id: APIC ID to check
++ */
++bool apic_id_is_primary_thread(unsigned int apicid)
++{
++ u32 mask;
++
++ if (smp_num_siblings == 1)
++ return true;
++ /* Isolate the SMT bit(s) in the APICID and check for 0 */
++ mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
++ return !(apicid & mask);
++}
++#endif
++
+ /*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
+index 3982f79d2377..ff0d14cd9e82 100644
+--- a/arch/x86/kernel/apic/io_apic.c
++++ b/arch/x86/kernel/apic/io_apic.c
+@@ -33,6 +33,7 @@
+
+ #include <linux/mm.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/init.h>
+ #include <linux/delay.h>
+ #include <linux/sched.h>
+diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
+index ce503c99f5c4..72a94401f9e0 100644
+--- a/arch/x86/kernel/apic/msi.c
++++ b/arch/x86/kernel/apic/msi.c
+@@ -12,6 +12,7 @@
+ */
+ #include <linux/mm.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/pci.h>
+ #include <linux/dmar.h>
+ #include <linux/hpet.h>
+diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
+index 35aaee4fc028..c9b773401fd8 100644
+--- a/arch/x86/kernel/apic/vector.c
++++ b/arch/x86/kernel/apic/vector.c
+@@ -11,6 +11,7 @@
+ * published by the Free Software Foundation.
+ */
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/seq_file.h>
+ #include <linux/init.h>
+ #include <linux/compiler.h>
+diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
+index 38915fbfae73..97e962afb967 100644
+--- a/arch/x86/kernel/cpu/amd.c
++++ b/arch/x86/kernel/cpu/amd.c
+@@ -315,6 +315,13 @@ static void legacy_fixup_core_id(struct cpuinfo_x86 *c)
+ c->cpu_core_id %= cus_per_node;
+ }
+
++
++static void amd_get_topology_early(struct cpuinfo_x86 *c)
++{
++ if (cpu_has(c, X86_FEATURE_TOPOEXT))
++ smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
++}
++
+ /*
+ * Fixup core topology information for
+ * (1) AMD multi-node processors
+@@ -334,7 +341,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
+ cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
+
+ node_id = ecx & 0xff;
+- smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
+
+ if (c->x86 == 0x15)
+ c->cu_id = ebx & 0xff;
+@@ -613,6 +619,7 @@ clear_sev:
+
+ static void early_init_amd(struct cpuinfo_x86 *c)
+ {
++ u64 value;
+ u32 dummy;
+
+ early_init_amd_mc(c);
+@@ -683,6 +690,22 @@ static void early_init_amd(struct cpuinfo_x86 *c)
+ set_cpu_bug(c, X86_BUG_AMD_E400);
+
+ early_detect_mem_encrypt(c);
++
++ /* Re-enable TopologyExtensions if switched off by BIOS */
++ if (c->x86 == 0x15 &&
++ (c->x86_model >= 0x10 && c->x86_model <= 0x6f) &&
++ !cpu_has(c, X86_FEATURE_TOPOEXT)) {
++
++ if (msr_set_bit(0xc0011005, 54) > 0) {
++ rdmsrl(0xc0011005, value);
++ if (value & BIT_64(54)) {
++ set_cpu_cap(c, X86_FEATURE_TOPOEXT);
++ pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
++ }
++ }
++ }
++
++ amd_get_topology_early(c);
+ }
+
+ static void init_amd_k8(struct cpuinfo_x86 *c)
+@@ -774,19 +797,6 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
+ {
+ u64 value;
+
+- /* re-enable TopologyExtensions if switched off by BIOS */
+- if ((c->x86_model >= 0x10) && (c->x86_model <= 0x6f) &&
+- !cpu_has(c, X86_FEATURE_TOPOEXT)) {
+-
+- if (msr_set_bit(0xc0011005, 54) > 0) {
+- rdmsrl(0xc0011005, value);
+- if (value & BIT_64(54)) {
+- set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+- pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
+- }
+- }
+- }
+-
+ /*
+ * The way access filter has a performance penalty on some workloads.
+ * Disable it on the affected CPUs.
+@@ -850,16 +860,9 @@ static void init_amd(struct cpuinfo_x86 *c)
+
+ cpu_detect_cache_sizes(c);
+
+- /* Multi core CPU? */
+- if (c->extended_cpuid_level >= 0x80000008) {
+- amd_detect_cmp(c);
+- amd_get_topology(c);
+- srat_detect_node(c);
+- }
+-
+-#ifdef CONFIG_X86_32
+- detect_ht(c);
+-#endif
++ amd_detect_cmp(c);
++ amd_get_topology(c);
++ srat_detect_node(c);
+
+ init_amd_cacheinfo(c);
+
+diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
+index 5c0ea39311fe..c4f0ae49a53d 100644
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -22,15 +22,18 @@
+ #include <asm/processor-flags.h>
+ #include <asm/fpu/internal.h>
+ #include <asm/msr.h>
++#include <asm/vmx.h>
+ #include <asm/paravirt.h>
+ #include <asm/alternative.h>
+ #include <asm/pgtable.h>
+ #include <asm/set_memory.h>
+ #include <asm/intel-family.h>
+ #include <asm/hypervisor.h>
++#include <asm/e820/api.h>
+
+ static void __init spectre_v2_select_mitigation(void);
+ static void __init ssb_select_mitigation(void);
++static void __init l1tf_select_mitigation(void);
+
+ /*
+ * Our boot-time value of the SPEC_CTRL MSR. We read it once so that any
+@@ -56,6 +59,12 @@ void __init check_bugs(void)
+ {
+ identify_boot_cpu();
+
++ /*
++ * identify_boot_cpu() initialized SMT support information, let the
++ * core code know.
++ */
++ cpu_smt_check_topology_early();
++
+ if (!IS_ENABLED(CONFIG_SMP)) {
+ pr_info("CPU: ");
+ print_cpu_info(&boot_cpu_data);
+@@ -82,6 +91,8 @@ void __init check_bugs(void)
+ */
+ ssb_select_mitigation();
+
++ l1tf_select_mitigation();
++
+ #ifdef CONFIG_X86_32
+ /*
+ * Check whether we are able to run this kernel safely on SMP.
+@@ -313,23 +324,6 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
+ return cmd;
+ }
+
+-/* Check for Skylake-like CPUs (for RSB handling) */
+-static bool __init is_skylake_era(void)
+-{
+- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+- boot_cpu_data.x86 == 6) {
+- switch (boot_cpu_data.x86_model) {
+- case INTEL_FAM6_SKYLAKE_MOBILE:
+- case INTEL_FAM6_SKYLAKE_DESKTOP:
+- case INTEL_FAM6_SKYLAKE_X:
+- case INTEL_FAM6_KABYLAKE_MOBILE:
+- case INTEL_FAM6_KABYLAKE_DESKTOP:
+- return true;
+- }
+- }
+- return false;
+-}
+-
+ static void __init spectre_v2_select_mitigation(void)
+ {
+ enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
+@@ -390,22 +384,15 @@ retpoline_auto:
+ pr_info("%s\n", spectre_v2_strings[mode]);
+
+ /*
+- * If neither SMEP nor PTI are available, there is a risk of
+- * hitting userspace addresses in the RSB after a context switch
+- * from a shallow call stack to a deeper one. To prevent this fill
+- * the entire RSB, even when using IBRS.
++ * If spectre v2 protection has been enabled, unconditionally fill
++ * RSB during a context switch; this protects against two independent
++ * issues:
+ *
+- * Skylake era CPUs have a separate issue with *underflow* of the
+- * RSB, when they will predict 'ret' targets from the generic BTB.
+- * The proper mitigation for this is IBRS. If IBRS is not supported
+- * or deactivated in favour of retpolines the RSB fill on context
+- * switch is required.
++ * - RSB underflow (and switch to BTB) on Skylake+
++ * - SpectreRSB variant of spectre v2 on X86_BUG_SPECTRE_V2 CPUs
+ */
+- if ((!boot_cpu_has(X86_FEATURE_PTI) &&
+- !boot_cpu_has(X86_FEATURE_SMEP)) || is_skylake_era()) {
+- setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
+- pr_info("Spectre v2 mitigation: Filling RSB on context switch\n");
+- }
++ setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
++ pr_info("Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch\n");
+
+ /* Initialize Indirect Branch Prediction Barrier if supported */
+ if (boot_cpu_has(X86_FEATURE_IBPB)) {
+@@ -654,8 +641,121 @@ void x86_spec_ctrl_setup_ap(void)
+ x86_amd_ssb_disable();
+ }
+
++#undef pr_fmt
++#define pr_fmt(fmt) "L1TF: " fmt
++
++/* Default mitigation for L1TF-affected CPUs */
++enum l1tf_mitigations l1tf_mitigation __ro_after_init = L1TF_MITIGATION_FLUSH;
++#if IS_ENABLED(CONFIG_KVM_INTEL)
++EXPORT_SYMBOL_GPL(l1tf_mitigation);
++
++enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
++EXPORT_SYMBOL_GPL(l1tf_vmx_mitigation);
++#endif
++
++static void __init l1tf_select_mitigation(void)
++{
++ u64 half_pa;
++
++ if (!boot_cpu_has_bug(X86_BUG_L1TF))
++ return;
++
++ switch (l1tf_mitigation) {
++ case L1TF_MITIGATION_OFF:
++ case L1TF_MITIGATION_FLUSH_NOWARN:
++ case L1TF_MITIGATION_FLUSH:
++ break;
++ case L1TF_MITIGATION_FLUSH_NOSMT:
++ case L1TF_MITIGATION_FULL:
++ cpu_smt_disable(false);
++ break;
++ case L1TF_MITIGATION_FULL_FORCE:
++ cpu_smt_disable(true);
++ break;
++ }
++
++#if CONFIG_PGTABLE_LEVELS == 2
++ pr_warn("Kernel not compiled for PAE. No mitigation for L1TF\n");
++ return;
++#endif
++
++ /*
++ * This is extremely unlikely to happen because almost all
++ * systems have far more MAX_PA/2 than RAM can be fit into
++ * DIMM slots.
++ */
++ half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
++ if (e820__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_RAM)) {
++ pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
++ return;
++ }
++
++ setup_force_cpu_cap(X86_FEATURE_L1TF_PTEINV);
++}
++
++static int __init l1tf_cmdline(char *str)
++{
++ if (!boot_cpu_has_bug(X86_BUG_L1TF))
++ return 0;
++
++ if (!str)
++ return -EINVAL;
++
++ if (!strcmp(str, "off"))
++ l1tf_mitigation = L1TF_MITIGATION_OFF;
++ else if (!strcmp(str, "flush,nowarn"))
++ l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOWARN;
++ else if (!strcmp(str, "flush"))
++ l1tf_mitigation = L1TF_MITIGATION_FLUSH;
++ else if (!strcmp(str, "flush,nosmt"))
++ l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOSMT;
++ else if (!strcmp(str, "full"))
++ l1tf_mitigation = L1TF_MITIGATION_FULL;
++ else if (!strcmp(str, "full,force"))
++ l1tf_mitigation = L1TF_MITIGATION_FULL_FORCE;
++
++ return 0;
++}
++early_param("l1tf", l1tf_cmdline);
++
++#undef pr_fmt
++
+ #ifdef CONFIG_SYSFS
+
++#define L1TF_DEFAULT_MSG "Mitigation: PTE Inversion"
++
++#if IS_ENABLED(CONFIG_KVM_INTEL)
++static const char *l1tf_vmx_states[] = {
++ [VMENTER_L1D_FLUSH_AUTO] = "auto",
++ [VMENTER_L1D_FLUSH_NEVER] = "vulnerable",
++ [VMENTER_L1D_FLUSH_COND] = "conditional cache flushes",
++ [VMENTER_L1D_FLUSH_ALWAYS] = "cache flushes",
++ [VMENTER_L1D_FLUSH_EPT_DISABLED] = "EPT disabled",
++ [VMENTER_L1D_FLUSH_NOT_REQUIRED] = "flush not necessary"
++};
++
++static ssize_t l1tf_show_state(char *buf)
++{
++ if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_AUTO)
++ return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
++
++ if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_EPT_DISABLED ||
++ (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER &&
++ cpu_smt_control == CPU_SMT_ENABLED))
++ return sprintf(buf, "%s; VMX: %s\n", L1TF_DEFAULT_MSG,
++ l1tf_vmx_states[l1tf_vmx_mitigation]);
++
++ return sprintf(buf, "%s; VMX: %s, SMT %s\n", L1TF_DEFAULT_MSG,
++ l1tf_vmx_states[l1tf_vmx_mitigation],
++ cpu_smt_control == CPU_SMT_ENABLED ? "vulnerable" : "disabled");
++}
++#else
++static ssize_t l1tf_show_state(char *buf)
++{
++ return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
++}
++#endif
++
+ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
+ char *buf, unsigned int bug)
+ {
+@@ -684,6 +784,10 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
+ case X86_BUG_SPEC_STORE_BYPASS:
+ return sprintf(buf, "%s\n", ssb_strings[ssb_mode]);
+
++ case X86_BUG_L1TF:
++ if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV))
++ return l1tf_show_state(buf);
++ break;
+ default:
+ break;
+ }
+@@ -710,4 +814,9 @@ ssize_t cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *
+ {
+ return cpu_show_common(dev, attr, buf, X86_BUG_SPEC_STORE_BYPASS);
+ }
++
++ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
++{
++ return cpu_show_common(dev, attr, buf, X86_BUG_L1TF);
++}
+ #endif
+diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
+index eb4cb3efd20e..9eda6f730ec4 100644
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -661,33 +661,36 @@ static void cpu_detect_tlb(struct cpuinfo_x86 *c)
+ tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
+ }
+
+-void detect_ht(struct cpuinfo_x86 *c)
++int detect_ht_early(struct cpuinfo_x86 *c)
+ {
+ #ifdef CONFIG_SMP
+ u32 eax, ebx, ecx, edx;
+- int index_msb, core_bits;
+- static bool printed;
+
+ if (!cpu_has(c, X86_FEATURE_HT))
+- return;
++ return -1;
+
+ if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
+- goto out;
++ return -1;
+
+ if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
+- return;
++ return -1;
+
+ cpuid(1, &eax, &ebx, &ecx, &edx);
+
+ smp_num_siblings = (ebx & 0xff0000) >> 16;
+-
+- if (smp_num_siblings == 1) {
++ if (smp_num_siblings == 1)
+ pr_info_once("CPU0: Hyper-Threading is disabled\n");
+- goto out;
+- }
++#endif
++ return 0;
++}
+
+- if (smp_num_siblings <= 1)
+- goto out;
++void detect_ht(struct cpuinfo_x86 *c)
++{
++#ifdef CONFIG_SMP
++ int index_msb, core_bits;
++
++ if (detect_ht_early(c) < 0)
++ return;
+
+ index_msb = get_count_order(smp_num_siblings);
+ c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
+@@ -700,15 +703,6 @@ void detect_ht(struct cpuinfo_x86 *c)
+
+ c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
+ ((1 << core_bits) - 1);
+-
+-out:
+- if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
+- pr_info("CPU: Physical Processor ID: %d\n",
+- c->phys_proc_id);
+- pr_info("CPU: Processor Core ID: %d\n",
+- c->cpu_core_id);
+- printed = 1;
+- }
+ #endif
+ }
+
+@@ -987,6 +981,21 @@ static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
+ {}
+ };
+
++static const __initconst struct x86_cpu_id cpu_no_l1tf[] = {
++ /* in addition to cpu_no_speculation */
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MERRIFIELD },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MOOREFIELD },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GOLDMONT },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_DENVERTON },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GEMINI_LAKE },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
++ { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
++ {}
++};
++
+ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
+ {
+ u64 ia32_cap = 0;
+@@ -1013,6 +1022,11 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
+ return;
+
+ setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
++
++ if (x86_match_cpu(cpu_no_l1tf))
++ return;
++
++ setup_force_cpu_bug(X86_BUG_L1TF);
+ }
+
+ /*
+diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
+index 38216f678fc3..e59c0ea82a33 100644
+--- a/arch/x86/kernel/cpu/cpu.h
++++ b/arch/x86/kernel/cpu/cpu.h
+@@ -55,7 +55,9 @@ extern void init_intel_cacheinfo(struct cpuinfo_x86 *c);
+ extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
+
+ extern void detect_num_cpu_cores(struct cpuinfo_x86 *c);
++extern int detect_extended_topology_early(struct cpuinfo_x86 *c);
+ extern int detect_extended_topology(struct cpuinfo_x86 *c);
++extern int detect_ht_early(struct cpuinfo_x86 *c);
+ extern void detect_ht(struct cpuinfo_x86 *c);
+
+ unsigned int aperfmperf_get_khz(int cpu);
+diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
+index eb75564f2d25..6602941cfebf 100644
+--- a/arch/x86/kernel/cpu/intel.c
++++ b/arch/x86/kernel/cpu/intel.c
+@@ -301,6 +301,13 @@ static void early_init_intel(struct cpuinfo_x86 *c)
+ }
+
+ check_mpx_erratum(c);
++
++ /*
++ * Get the number of SMT siblings early from the extended topology
++ * leaf, if available. Otherwise try the legacy SMT detection.
++ */
++ if (detect_extended_topology_early(c) < 0)
++ detect_ht_early(c);
+ }
+
+ #ifdef CONFIG_X86_32
+diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
+index 08286269fd24..b9bc8a1a584e 100644
+--- a/arch/x86/kernel/cpu/microcode/core.c
++++ b/arch/x86/kernel/cpu/microcode/core.c
+@@ -509,12 +509,20 @@ static struct platform_device *microcode_pdev;
+
+ static int check_online_cpus(void)
+ {
+- if (num_online_cpus() == num_present_cpus())
+- return 0;
++ unsigned int cpu;
+
+- pr_err("Not all CPUs online, aborting microcode update.\n");
++ /*
++ * Make sure all CPUs are online. It's fine for SMT to be disabled if
++ * all the primary threads are still online.
++ */
++ for_each_present_cpu(cpu) {
++ if (topology_is_primary_thread(cpu) && !cpu_online(cpu)) {
++ pr_err("Not all CPUs online, aborting microcode update.\n");
++ return -EINVAL;
++ }
++ }
+
+- return -EINVAL;
++ return 0;
+ }
+
+ static atomic_t late_cpus_in;
+diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
+index 81c0afb39d0a..71ca064e3794 100644
+--- a/arch/x86/kernel/cpu/topology.c
++++ b/arch/x86/kernel/cpu/topology.c
+@@ -22,18 +22,10 @@
+ #define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f)
+ #define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff)
+
+-/*
+- * Check for extended topology enumeration cpuid leaf 0xb and if it
+- * exists, use it for populating initial_apicid and cpu topology
+- * detection.
+- */
+-int detect_extended_topology(struct cpuinfo_x86 *c)
++int detect_extended_topology_early(struct cpuinfo_x86 *c)
+ {
+ #ifdef CONFIG_SMP
+- unsigned int eax, ebx, ecx, edx, sub_index;
+- unsigned int ht_mask_width, core_plus_mask_width;
+- unsigned int core_select_mask, core_level_siblings;
+- static bool printed;
++ unsigned int eax, ebx, ecx, edx;
+
+ if (c->cpuid_level < 0xb)
+ return -1;
+@@ -52,10 +44,30 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
+ * initial apic id, which also represents 32-bit extended x2apic id.
+ */
+ c->initial_apicid = edx;
++ smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
++#endif
++ return 0;
++}
++
++/*
++ * Check for extended topology enumeration cpuid leaf 0xb and if it
++ * exists, use it for populating initial_apicid and cpu topology
++ * detection.
++ */
++int detect_extended_topology(struct cpuinfo_x86 *c)
++{
++#ifdef CONFIG_SMP
++ unsigned int eax, ebx, ecx, edx, sub_index;
++ unsigned int ht_mask_width, core_plus_mask_width;
++ unsigned int core_select_mask, core_level_siblings;
++
++ if (detect_extended_topology_early(c) < 0)
++ return -1;
+
+ /*
+ * Populate HT related information from sub-leaf level 0.
+ */
++ cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
+ core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
+ core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+
+@@ -86,15 +98,6 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
+ c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
+
+ c->x86_max_cores = (core_level_siblings / smp_num_siblings);
+-
+- if (!printed) {
+- pr_info("CPU: Physical Processor ID: %d\n",
+- c->phys_proc_id);
+- if (c->x86_max_cores > 1)
+- pr_info("CPU: Processor Core ID: %d\n",
+- c->cpu_core_id);
+- printed = 1;
+- }
+ #endif
+ return 0;
+ }
+diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
+index f92a6593de1e..2ea85b32421a 100644
+--- a/arch/x86/kernel/fpu/core.c
++++ b/arch/x86/kernel/fpu/core.c
+@@ -10,6 +10,7 @@
+ #include <asm/fpu/signal.h>
+ #include <asm/fpu/types.h>
+ #include <asm/traps.h>
++#include <asm/irq_regs.h>
+
+ #include <linux/hardirq.h>
+ #include <linux/pkeys.h>
+diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
+index 346b24883911..b0acb22e5a46 100644
+--- a/arch/x86/kernel/hpet.c
++++ b/arch/x86/kernel/hpet.c
+@@ -1,6 +1,7 @@
+ #include <linux/clocksource.h>
+ #include <linux/clockchips.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/export.h>
+ #include <linux/delay.h>
+ #include <linux/errno.h>
+diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
+index 86c4439f9d74..519649ddf100 100644
+--- a/arch/x86/kernel/i8259.c
++++ b/arch/x86/kernel/i8259.c
+@@ -5,6 +5,7 @@
+ #include <linux/sched.h>
+ #include <linux/ioport.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/timex.h>
+ #include <linux/random.h>
+ #include <linux/init.h>
+diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
+index 74383a3780dc..01adea278a71 100644
+--- a/arch/x86/kernel/idt.c
++++ b/arch/x86/kernel/idt.c
+@@ -8,6 +8,7 @@
+ #include <asm/traps.h>
+ #include <asm/proto.h>
+ #include <asm/desc.h>
++#include <asm/hw_irq.h>
+
+ struct idt_data {
+ unsigned int vector;
+diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
+index 328d027d829d..59b5f2ea7c2f 100644
+--- a/arch/x86/kernel/irq.c
++++ b/arch/x86/kernel/irq.c
+@@ -10,6 +10,7 @@
+ #include <linux/ftrace.h>
+ #include <linux/delay.h>
+ #include <linux/export.h>
++#include <linux/irq.h>
+
+ #include <asm/apic.h>
+ #include <asm/io_apic.h>
+diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
+index c1bdbd3d3232..95600a99ae93 100644
+--- a/arch/x86/kernel/irq_32.c
++++ b/arch/x86/kernel/irq_32.c
+@@ -11,6 +11,7 @@
+
+ #include <linux/seq_file.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/kernel_stat.h>
+ #include <linux/notifier.h>
+ #include <linux/cpu.h>
+diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
+index d86e344f5b3d..0469cd078db1 100644
+--- a/arch/x86/kernel/irq_64.c
++++ b/arch/x86/kernel/irq_64.c
+@@ -11,6 +11,7 @@
+
+ #include <linux/kernel_stat.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/seq_file.h>
+ #include <linux/delay.h>
+ #include <linux/ftrace.h>
+diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
+index 772196c1b8c4..a0693b71cfc1 100644
+--- a/arch/x86/kernel/irqinit.c
++++ b/arch/x86/kernel/irqinit.c
+@@ -5,6 +5,7 @@
+ #include <linux/sched.h>
+ #include <linux/ioport.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/timex.h>
+ #include <linux/random.h>
+ #include <linux/kprobes.h>
+diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
+index 6f4d42377fe5..44e26dc326d5 100644
+--- a/arch/x86/kernel/kprobes/core.c
++++ b/arch/x86/kernel/kprobes/core.c
+@@ -395,8 +395,6 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn)
+ - (u8 *) real;
+ if ((s64) (s32) newdisp != newdisp) {
+ pr_err("Kprobes error: new displacement does not fit into s32 (%llx)\n", newdisp);
+- pr_err("\tSrc: %p, Dest: %p, old disp: %x\n",
+- src, real, insn->displacement.value);
+ return 0;
+ }
+ disp = (u8 *) dest + insn_offset_displacement(insn);
+@@ -640,8 +638,7 @@ static int reenter_kprobe(struct kprobe *p, struct pt_regs *regs,
+ * Raise a BUG or we'll continue in an endless reentering loop
+ * and eventually a stack overflow.
+ */
+- printk(KERN_WARNING "Unrecoverable kprobe detected at %p.\n",
+- p->addr);
++ pr_err("Unrecoverable kprobe detected.\n");
+ dump_kprobe(p);
+ BUG();
+ default:
+diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
+index 99dc79e76bdc..930c88341e4e 100644
+--- a/arch/x86/kernel/paravirt.c
++++ b/arch/x86/kernel/paravirt.c
+@@ -88,10 +88,12 @@ unsigned paravirt_patch_call(void *insnbuf,
+ struct branch *b = insnbuf;
+ unsigned long delta = (unsigned long)target - (addr+5);
+
+- if (tgt_clobbers & ~site_clobbers)
+- return len; /* target would clobber too much for this site */
+- if (len < 5)
++ if (len < 5) {
++#ifdef CONFIG_RETPOLINE
++ WARN_ONCE("Failing to patch indirect CALL in %ps\n", (void *)addr);
++#endif
+ return len; /* call too long for patch site */
++ }
+
+ b->opcode = 0xe8; /* call */
+ b->delta = delta;
+@@ -106,8 +108,12 @@ unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
+ struct branch *b = insnbuf;
+ unsigned long delta = (unsigned long)target - (addr+5);
+
+- if (len < 5)
++ if (len < 5) {
++#ifdef CONFIG_RETPOLINE
++ WARN_ONCE("Failing to patch indirect JMP in %ps\n", (void *)addr);
++#endif
+ return len; /* call too long for patch site */
++ }
+
+ b->opcode = 0xe9; /* jmp */
+ b->delta = delta;
+diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
+index 2f86d883dd95..74b4472ba0a6 100644
+--- a/arch/x86/kernel/setup.c
++++ b/arch/x86/kernel/setup.c
+@@ -823,6 +823,12 @@ void __init setup_arch(char **cmdline_p)
+ memblock_reserve(__pa_symbol(_text),
+ (unsigned long)__bss_stop - (unsigned long)_text);
+
++ /*
++ * Make sure page 0 is always reserved because on systems with
++ * L1TF its contents can be leaked to user processes.
++ */
++ memblock_reserve(0, PAGE_SIZE);
++
+ early_reserve_initrd();
+
+ /*
+diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
+index 5c574dff4c1a..04adc8d60aed 100644
+--- a/arch/x86/kernel/smp.c
++++ b/arch/x86/kernel/smp.c
+@@ -261,6 +261,7 @@ __visible void __irq_entry smp_reschedule_interrupt(struct pt_regs *regs)
+ {
+ ack_APIC_irq();
+ inc_irq_stat(irq_resched_count);
++ kvm_set_cpu_l1tf_flush_l1d();
+
+ if (trace_resched_ipi_enabled()) {
+ /*
+diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
+index db9656e13ea0..f02ecaf97904 100644
+--- a/arch/x86/kernel/smpboot.c
++++ b/arch/x86/kernel/smpboot.c
+@@ -80,6 +80,7 @@
+ #include <asm/intel-family.h>
+ #include <asm/cpu_device_id.h>
+ #include <asm/spec-ctrl.h>
++#include <asm/hw_irq.h>
+
+ /* representing HT siblings of each logical CPU */
+ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
+@@ -270,6 +271,23 @@ static void notrace start_secondary(void *unused)
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+ }
+
++/**
++ * topology_is_primary_thread - Check whether CPU is the primary SMT thread
++ * @cpu: CPU to check
++ */
++bool topology_is_primary_thread(unsigned int cpu)
++{
++ return apic_id_is_primary_thread(per_cpu(x86_cpu_to_apicid, cpu));
++}
++
++/**
++ * topology_smt_supported - Check whether SMT is supported by the CPUs
++ */
++bool topology_smt_supported(void)
++{
++ return smp_num_siblings > 1;
++}
++
+ /**
+ * topology_phys_to_logical_pkg - Map a physical package id to a logical
+ *
+diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
+index 774ebafa97c4..be01328eb755 100644
+--- a/arch/x86/kernel/time.c
++++ b/arch/x86/kernel/time.c
+@@ -12,6 +12,7 @@
+
+ #include <linux/clockchips.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+ #include <linux/i8253.h>
+ #include <linux/time.h>
+ #include <linux/export.h>
+diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
+index 6b8f11521c41..a44e568363a4 100644
+--- a/arch/x86/kvm/mmu.c
++++ b/arch/x86/kvm/mmu.c
+@@ -3840,6 +3840,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
+ {
+ int r = 1;
+
++ vcpu->arch.l1tf_flush_l1d = true;
+ switch (vcpu->arch.apf.host_apf_reason) {
+ default:
+ trace_kvm_page_fault(fault_address, error_code);
+diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
+index 5d8e317c2b04..46b428c0990e 100644
+--- a/arch/x86/kvm/vmx.c
++++ b/arch/x86/kvm/vmx.c
+@@ -188,6 +188,150 @@ module_param(ple_window_max, uint, 0444);
+
+ extern const ulong vmx_return;
+
++static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush);
++static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond);
++static DEFINE_MUTEX(vmx_l1d_flush_mutex);
++
++/* Storage for pre module init parameter parsing */
++static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO;
++
++static const struct {
++ const char *option;
++ enum vmx_l1d_flush_state cmd;
++} vmentry_l1d_param[] = {
++ {"auto", VMENTER_L1D_FLUSH_AUTO},
++ {"never", VMENTER_L1D_FLUSH_NEVER},
++ {"cond", VMENTER_L1D_FLUSH_COND},
++ {"always", VMENTER_L1D_FLUSH_ALWAYS},
++};
++
++#define L1D_CACHE_ORDER 4
++static void *vmx_l1d_flush_pages;
++
++static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf)
++{
++ struct page *page;
++ unsigned int i;
++
++ if (!enable_ept) {
++ l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_EPT_DISABLED;
++ return 0;
++ }
++
++ if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) {
++ u64 msr;
++
++ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, msr);
++ if (msr & ARCH_CAP_SKIP_VMENTRY_L1DFLUSH) {
++ l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED;
++ return 0;
++ }
++ }
++
++ /* If set to auto use the default l1tf mitigation method */
++ if (l1tf == VMENTER_L1D_FLUSH_AUTO) {
++ switch (l1tf_mitigation) {
++ case L1TF_MITIGATION_OFF:
++ l1tf = VMENTER_L1D_FLUSH_NEVER;
++ break;
++ case L1TF_MITIGATION_FLUSH_NOWARN:
++ case L1TF_MITIGATION_FLUSH:
++ case L1TF_MITIGATION_FLUSH_NOSMT:
++ l1tf = VMENTER_L1D_FLUSH_COND;
++ break;
++ case L1TF_MITIGATION_FULL:
++ case L1TF_MITIGATION_FULL_FORCE:
++ l1tf = VMENTER_L1D_FLUSH_ALWAYS;
++ break;
++ }
++ } else if (l1tf_mitigation == L1TF_MITIGATION_FULL_FORCE) {
++ l1tf = VMENTER_L1D_FLUSH_ALWAYS;
++ }
++
++ if (l1tf != VMENTER_L1D_FLUSH_NEVER && !vmx_l1d_flush_pages &&
++ !boot_cpu_has(X86_FEATURE_FLUSH_L1D)) {
++ page = alloc_pages(GFP_KERNEL, L1D_CACHE_ORDER);
++ if (!page)
++ return -ENOMEM;
++ vmx_l1d_flush_pages = page_address(page);
++
++ /*
++ * Initialize each page with a different pattern in
++ * order to protect against KSM in the nested
++ * virtualization case.
++ */
++ for (i = 0; i < 1u << L1D_CACHE_ORDER; ++i) {
++ memset(vmx_l1d_flush_pages + i * PAGE_SIZE, i + 1,
++ PAGE_SIZE);
++ }
++ }
++
++ l1tf_vmx_mitigation = l1tf;
++
++ if (l1tf != VMENTER_L1D_FLUSH_NEVER)
++ static_branch_enable(&vmx_l1d_should_flush);
++ else
++ static_branch_disable(&vmx_l1d_should_flush);
++
++ if (l1tf == VMENTER_L1D_FLUSH_COND)
++ static_branch_enable(&vmx_l1d_flush_cond);
++ else
++ static_branch_disable(&vmx_l1d_flush_cond);
++ return 0;
++}
++
++static int vmentry_l1d_flush_parse(const char *s)
++{
++ unsigned int i;
++
++ if (s) {
++ for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
++ if (sysfs_streq(s, vmentry_l1d_param[i].option))
++ return vmentry_l1d_param[i].cmd;
++ }
++ }
++ return -EINVAL;
++}
++
++static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp)
++{
++ int l1tf, ret;
++
++ if (!boot_cpu_has(X86_BUG_L1TF))
++ return 0;
++
++ l1tf = vmentry_l1d_flush_parse(s);
++ if (l1tf < 0)
++ return l1tf;
++
++ /*
++ * Has vmx_init() run already? If not then this is the pre init
++ * parameter parsing. In that case just store the value and let
++ * vmx_init() do the proper setup after enable_ept has been
++ * established.
++ */
++ if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_AUTO) {
++ vmentry_l1d_flush_param = l1tf;
++ return 0;
++ }
++
++ mutex_lock(&vmx_l1d_flush_mutex);
++ ret = vmx_setup_l1d_flush(l1tf);
++ mutex_unlock(&vmx_l1d_flush_mutex);
++ return ret;
++}
++
++static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
++{
++ return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
++}
++
++static const struct kernel_param_ops vmentry_l1d_flush_ops = {
++ .set = vmentry_l1d_flush_set,
++ .get = vmentry_l1d_flush_get,
++};
++module_param_cb(vmentry_l1d_flush, &vmentry_l1d_flush_ops, NULL, 0644);
++
+ struct kvm_vmx {
+ struct kvm kvm;
+
+@@ -757,6 +901,11 @@ static inline int pi_test_sn(struct pi_desc *pi_desc)
+ (unsigned long *)&pi_desc->control);
+ }
+
++struct vmx_msrs {
++ unsigned int nr;
++ struct vmx_msr_entry val[NR_AUTOLOAD_MSRS];
++};
++
+ struct vcpu_vmx {
+ struct kvm_vcpu vcpu;
+ unsigned long host_rsp;
+@@ -790,9 +939,8 @@ struct vcpu_vmx {
+ struct loaded_vmcs *loaded_vmcs;
+ bool __launched; /* temporary, used in vmx_vcpu_run */
+ struct msr_autoload {
+- unsigned nr;
+- struct vmx_msr_entry guest[NR_AUTOLOAD_MSRS];
+- struct vmx_msr_entry host[NR_AUTOLOAD_MSRS];
++ struct vmx_msrs guest;
++ struct vmx_msrs host;
+ } msr_autoload;
+ struct {
+ int loaded;
+@@ -2377,9 +2525,20 @@ static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
+ vm_exit_controls_clearbit(vmx, exit);
+ }
+
++static int find_msr(struct vmx_msrs *m, unsigned int msr)
++{
++ unsigned int i;
++
++ for (i = 0; i < m->nr; ++i) {
++ if (m->val[i].index == msr)
++ return i;
++ }
++ return -ENOENT;
++}
++
+ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
+ {
+- unsigned i;
++ int i;
+ struct msr_autoload *m = &vmx->msr_autoload;
+
+ switch (msr) {
+@@ -2400,18 +2559,21 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
+ }
+ break;
+ }
++ i = find_msr(&m->guest, msr);
++ if (i < 0)
++ goto skip_guest;
++ --m->guest.nr;
++ m->guest.val[i] = m->guest.val[m->guest.nr];
++ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
+
+- for (i = 0; i < m->nr; ++i)
+- if (m->guest[i].index == msr)
+- break;
+-
+- if (i == m->nr)
++skip_guest:
++ i = find_msr(&m->host, msr);
++ if (i < 0)
+ return;
+- --m->nr;
+- m->guest[i] = m->guest[m->nr];
+- m->host[i] = m->host[m->nr];
+- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
+- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
++
++ --m->host.nr;
++ m->host.val[i] = m->host.val[m->host.nr];
++ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
+ }
+
+ static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,
+@@ -2426,9 +2588,9 @@ static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,
+ }
+
+ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
+- u64 guest_val, u64 host_val)
++ u64 guest_val, u64 host_val, bool entry_only)
+ {
+- unsigned i;
++ int i, j = 0;
+ struct msr_autoload *m = &vmx->msr_autoload;
+
+ switch (msr) {
+@@ -2463,24 +2625,31 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
+ wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
+ }
+
+- for (i = 0; i < m->nr; ++i)
+- if (m->guest[i].index == msr)
+- break;
++ i = find_msr(&m->guest, msr);
++ if (!entry_only)
++ j = find_msr(&m->host, msr);
+
+- if (i == NR_AUTOLOAD_MSRS) {
++ if (i == NR_AUTOLOAD_MSRS || j == NR_AUTOLOAD_MSRS) {
+ printk_once(KERN_WARNING "Not enough msr switch entries. "
+ "Can't add msr %x\n", msr);
+ return;
+- } else if (i == m->nr) {
+- ++m->nr;
+- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
+- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
+ }
++ if (i < 0) {
++ i = m->guest.nr++;
++ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
++ }
++ m->guest.val[i].index = msr;
++ m->guest.val[i].value = guest_val;
++
++ if (entry_only)
++ return;
+
+- m->guest[i].index = msr;
+- m->guest[i].value = guest_val;
+- m->host[i].index = msr;
+- m->host[i].value = host_val;
++ if (j < 0) {
++ j = m->host.nr++;
++ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
++ }
++ m->host.val[j].index = msr;
++ m->host.val[j].value = host_val;
+ }
+
+ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
+@@ -2524,7 +2693,7 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
+ guest_efer &= ~EFER_LME;
+ if (guest_efer != host_efer)
+ add_atomic_switch_msr(vmx, MSR_EFER,
+- guest_efer, host_efer);
++ guest_efer, host_efer, false);
+ return false;
+ } else {
+ guest_efer &= ~ignore_bits;
+@@ -3987,7 +4156,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+ vcpu->arch.ia32_xss = data;
+ if (vcpu->arch.ia32_xss != host_xss)
+ add_atomic_switch_msr(vmx, MSR_IA32_XSS,
+- vcpu->arch.ia32_xss, host_xss);
++ vcpu->arch.ia32_xss, host_xss, false);
+ else
+ clear_atomic_switch_msr(vmx, MSR_IA32_XSS);
+ break;
+@@ -6274,9 +6443,9 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
+
+ vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
+ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
+- vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host));
++ vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val));
+ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);
+- vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest));
++ vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest.val));
+
+ if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
+ vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
+@@ -6296,8 +6465,7 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
+ ++vmx->nmsrs;
+ }
+
+- if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+- rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities);
++ vmx->arch_capabilities = kvm_get_arch_capabilities();
+
+ vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
+
+@@ -9548,6 +9716,79 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
+ }
+ }
+
++/*
++ * Software based L1D cache flush which is used when microcode providing
++ * the cache control MSR is not loaded.
++ *
++ * The L1D cache is 32 KiB on Nehalem and later microarchitectures, but to
++ * flush it is required to read in 64 KiB because the replacement algorithm
++ * is not exactly LRU. This could be sized at runtime via topology
++ * information but as all relevant affected CPUs have 32KiB L1D cache size
++ * there is no point in doing so.
++ */
++#define L1D_CACHE_ORDER 4
++static void *vmx_l1d_flush_pages;
++
++static void vmx_l1d_flush(struct kvm_vcpu *vcpu)
++{
++ int size = PAGE_SIZE << L1D_CACHE_ORDER;
++
++ /*
++ * This code is only executed when the the flush mode is 'cond' or
++ * 'always'
++ */
++ if (static_branch_likely(&vmx_l1d_flush_cond)) {
++ bool flush_l1d;
++
++ /*
++ * Clear the per-vcpu flush bit, it gets set again
++ * either from vcpu_run() or from one of the unsafe
++ * VMEXIT handlers.
++ */
++ flush_l1d = vcpu->arch.l1tf_flush_l1d;
++ vcpu->arch.l1tf_flush_l1d = false;
++
++ /*
++ * Clear the per-cpu flush bit, it gets set again from
++ * the interrupt handlers.
++ */
++ flush_l1d |= kvm_get_cpu_l1tf_flush_l1d();
++ kvm_clear_cpu_l1tf_flush_l1d();
++
++ if (!flush_l1d)
++ return;
++ }
++
++ vcpu->stat.l1d_flush++;
++
++ if (static_cpu_has(X86_FEATURE_FLUSH_L1D)) {
++ wrmsrl(MSR_IA32_FLUSH_CMD, L1D_FLUSH);
++ return;
++ }
++
++ asm volatile(
++ /* First ensure the pages are in the TLB */
++ "xorl %%eax, %%eax\n"
++ ".Lpopulate_tlb:\n\t"
++ "movzbl (%[flush_pages], %%" _ASM_AX "), %%ecx\n\t"
++ "addl $4096, %%eax\n\t"
++ "cmpl %%eax, %[size]\n\t"
++ "jne .Lpopulate_tlb\n\t"
++ "xorl %%eax, %%eax\n\t"
++ "cpuid\n\t"
++ /* Now fill the cache */
++ "xorl %%eax, %%eax\n"
++ ".Lfill_cache:\n"
++ "movzbl (%[flush_pages], %%" _ASM_AX "), %%ecx\n\t"
++ "addl $64, %%eax\n\t"
++ "cmpl %%eax, %[size]\n\t"
++ "jne .Lfill_cache\n\t"
++ "lfence\n"
++ :: [flush_pages] "r" (vmx_l1d_flush_pages),
++ [size] "r" (size)
++ : "eax", "ebx", "ecx", "edx");
++}
++
+ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
+ {
+ struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+@@ -9949,7 +10190,7 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
+ clear_atomic_switch_msr(vmx, msrs[i].msr);
+ else
+ add_atomic_switch_msr(vmx, msrs[i].msr, msrs[i].guest,
+- msrs[i].host);
++ msrs[i].host, false);
+ }
+
+ static void vmx_arm_hv_timer(struct kvm_vcpu *vcpu)
+@@ -10044,6 +10285,9 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
+ evmcs_rsp = static_branch_unlikely(&enable_evmcs) ?
+ (unsigned long)¤t_evmcs->host_rsp : 0;
+
++ if (static_branch_unlikely(&vmx_l1d_should_flush))
++ vmx_l1d_flush(vcpu);
++
+ asm(
+ /* Store host registers */
+ "push %%" _ASM_DX "; push %%" _ASM_BP ";"
+@@ -10403,10 +10647,37 @@ free_vcpu:
+ return ERR_PTR(err);
+ }
+
++#define L1TF_MSG_SMT "L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details.\n"
++#define L1TF_MSG_L1D "L1TF CPU bug present and virtualization mitigation disabled, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details.\n"
++
+ static int vmx_vm_init(struct kvm *kvm)
+ {
+ if (!ple_gap)
+ kvm->arch.pause_in_guest = true;
++
++ if (boot_cpu_has(X86_BUG_L1TF) && enable_ept) {
++ switch (l1tf_mitigation) {
++ case L1TF_MITIGATION_OFF:
++ case L1TF_MITIGATION_FLUSH_NOWARN:
++ /* 'I explicitly don't care' is set */
++ break;
++ case L1TF_MITIGATION_FLUSH:
++ case L1TF_MITIGATION_FLUSH_NOSMT:
++ case L1TF_MITIGATION_FULL:
++ /*
++ * Warn upon starting the first VM in a potentially
++ * insecure environment.
++ */
++ if (cpu_smt_control == CPU_SMT_ENABLED)
++ pr_warn_once(L1TF_MSG_SMT);
++ if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER)
++ pr_warn_once(L1TF_MSG_L1D);
++ break;
++ case L1TF_MITIGATION_FULL_FORCE:
++ /* Flush is enforced */
++ break;
++ }
++ }
+ return 0;
+ }
+
+@@ -11260,10 +11531,10 @@ static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
+ * Set the MSR load/store lists to match L0's settings.
+ */
+ vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
+- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+- vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host));
+- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+- vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest));
++ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
++ vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val));
++ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
++ vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest.val));
+
+ set_cr4_guest_host_mask(vmx);
+
+@@ -11899,6 +12170,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
+ return ret;
+ }
+
++ /* Hide L1D cache contents from the nested guest. */
++ vmx->vcpu.arch.l1tf_flush_l1d = true;
++
+ /*
+ * If we're entering a halted L2 vcpu and the L2 vcpu won't be woken
+ * by event injection, halt vcpu.
+@@ -12419,8 +12693,8 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
+ vmx_segment_cache_clear(vmx);
+
+ /* Update any VMCS fields that might have changed while L2 ran */
+- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
++ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
++ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
+ vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset);
+ if (vmx->hv_deadline_tsc == -1)
+ vmcs_clear_bits(PIN_BASED_VM_EXEC_CONTROL,
+@@ -13137,6 +13411,51 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
+ .enable_smi_window = enable_smi_window,
+ };
+
++static void vmx_cleanup_l1d_flush(void)
++{
++ if (vmx_l1d_flush_pages) {
++ free_pages((unsigned long)vmx_l1d_flush_pages, L1D_CACHE_ORDER);
++ vmx_l1d_flush_pages = NULL;
++ }
++ /* Restore state so sysfs ignores VMX */
++ l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
++}
++
++static void vmx_exit(void)
++{
++#ifdef CONFIG_KEXEC_CORE
++ RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
++ synchronize_rcu();
++#endif
++
++ kvm_exit();
++
++#if IS_ENABLED(CONFIG_HYPERV)
++ if (static_branch_unlikely(&enable_evmcs)) {
++ int cpu;
++ struct hv_vp_assist_page *vp_ap;
++ /*
++ * Reset everything to support using non-enlightened VMCS
++ * access later (e.g. when we reload the module with
++ * enlightened_vmcs=0)
++ */
++ for_each_online_cpu(cpu) {
++ vp_ap = hv_get_vp_assist_page(cpu);
++
++ if (!vp_ap)
++ continue;
++
++ vp_ap->current_nested_vmcs = 0;
++ vp_ap->enlighten_vmentry = 0;
++ }
++
++ static_branch_disable(&enable_evmcs);
++ }
++#endif
++ vmx_cleanup_l1d_flush();
++}
++module_exit(vmx_exit);
++
+ static int __init vmx_init(void)
+ {
+ int r;
+@@ -13171,10 +13490,25 @@ static int __init vmx_init(void)
+ #endif
+
+ r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx),
+- __alignof__(struct vcpu_vmx), THIS_MODULE);
++ __alignof__(struct vcpu_vmx), THIS_MODULE);
+ if (r)
+ return r;
+
++ /*
++ * Must be called after kvm_init() so enable_ept is properly set
++ * up. Hand the parameter mitigation value in which was stored in
++ * the pre module init parser. If no parameter was given, it will
++ * contain 'auto' which will be turned into the default 'cond'
++ * mitigation mode.
++ */
++ if (boot_cpu_has(X86_BUG_L1TF)) {
++ r = vmx_setup_l1d_flush(vmentry_l1d_flush_param);
++ if (r) {
++ vmx_exit();
++ return r;
++ }
++ }
++
+ #ifdef CONFIG_KEXEC_CORE
+ rcu_assign_pointer(crash_vmclear_loaded_vmcss,
+ crash_vmclear_local_loaded_vmcss);
+@@ -13183,39 +13517,4 @@ static int __init vmx_init(void)
+
+ return 0;
+ }
+-
+-static void __exit vmx_exit(void)
+-{
+-#ifdef CONFIG_KEXEC_CORE
+- RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
+- synchronize_rcu();
+-#endif
+-
+- kvm_exit();
+-
+-#if IS_ENABLED(CONFIG_HYPERV)
+- if (static_branch_unlikely(&enable_evmcs)) {
+- int cpu;
+- struct hv_vp_assist_page *vp_ap;
+- /*
+- * Reset everything to support using non-enlightened VMCS
+- * access later (e.g. when we reload the module with
+- * enlightened_vmcs=0)
+- */
+- for_each_online_cpu(cpu) {
+- vp_ap = hv_get_vp_assist_page(cpu);
+-
+- if (!vp_ap)
+- continue;
+-
+- vp_ap->current_nested_vmcs = 0;
+- vp_ap->enlighten_vmentry = 0;
+- }
+-
+- static_branch_disable(&enable_evmcs);
+- }
+-#endif
+-}
+-
+-module_init(vmx_init)
+-module_exit(vmx_exit)
++module_init(vmx_init);
+diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
+index 2b812b3c5088..a5caa5e5480c 100644
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -195,6 +195,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
+ { "irq_injections", VCPU_STAT(irq_injections) },
+ { "nmi_injections", VCPU_STAT(nmi_injections) },
+ { "req_event", VCPU_STAT(req_event) },
++ { "l1d_flush", VCPU_STAT(l1d_flush) },
+ { "mmu_shadow_zapped", VM_STAT(mmu_shadow_zapped) },
+ { "mmu_pte_write", VM_STAT(mmu_pte_write) },
+ { "mmu_pte_updated", VM_STAT(mmu_pte_updated) },
+@@ -1102,11 +1103,35 @@ static u32 msr_based_features[] = {
+
+ static unsigned int num_msr_based_features;
+
++u64 kvm_get_arch_capabilities(void)
++{
++ u64 data;
++
++ rdmsrl_safe(MSR_IA32_ARCH_CAPABILITIES, &data);
++
++ /*
++ * If we're doing cache flushes (either "always" or "cond")
++ * we will do one whenever the guest does a vmlaunch/vmresume.
++ * If an outer hypervisor is doing the cache flush for us
++ * (VMENTER_L1D_FLUSH_NESTED_VM), we can safely pass that
++ * capability to the guest too, and if EPT is disabled we're not
++ * vulnerable. Overall, only VMENTER_L1D_FLUSH_NEVER will
++ * require a nested hypervisor to do a flush of its own.
++ */
++ if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER)
++ data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH;
++
++ return data;
++}
++EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities);
++
+ static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
+ {
+ switch (msr->index) {
+- case MSR_IA32_UCODE_REV:
+ case MSR_IA32_ARCH_CAPABILITIES:
++ msr->data = kvm_get_arch_capabilities();
++ break;
++ case MSR_IA32_UCODE_REV:
+ rdmsrl_safe(msr->index, &msr->data);
+ break;
+ default:
+@@ -4876,6 +4901,9 @@ static int emulator_write_std(struct x86_emulate_ctxt *ctxt, gva_t addr, void *v
+ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
+ unsigned int bytes, struct x86_exception *exception)
+ {
++ /* kvm_write_guest_virt_system can pull in tons of pages. */
++ vcpu->arch.l1tf_flush_l1d = true;
++
+ return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
+ PFERR_WRITE_MASK, exception);
+ }
+@@ -6052,6 +6080,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
+ bool writeback = true;
+ bool write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable;
+
++ vcpu->arch.l1tf_flush_l1d = true;
++
+ /*
+ * Clear write_fault_to_shadow_pgtable here to ensure it is
+ * never reused.
+@@ -7581,6 +7611,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
+ struct kvm *kvm = vcpu->kvm;
+
+ vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
++ vcpu->arch.l1tf_flush_l1d = true;
+
+ for (;;) {
+ if (kvm_vcpu_running(vcpu)) {
+@@ -8700,6 +8731,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
+
+ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
+ {
++ vcpu->arch.l1tf_flush_l1d = true;
+ kvm_x86_ops->sched_in(vcpu, cpu);
+ }
+
+diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
+index cee58a972cb2..83241eb71cd4 100644
+--- a/arch/x86/mm/init.c
++++ b/arch/x86/mm/init.c
+@@ -4,6 +4,8 @@
+ #include <linux/swap.h>
+ #include <linux/memblock.h>
+ #include <linux/bootmem.h> /* for max_low_pfn */
++#include <linux/swapfile.h>
++#include <linux/swapops.h>
+
+ #include <asm/set_memory.h>
+ #include <asm/e820/api.h>
+@@ -880,3 +882,26 @@ void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
+ __cachemode2pte_tbl[cache] = __cm_idx2pte(entry);
+ __pte2cachemode_tbl[entry] = cache;
+ }
++
++#ifdef CONFIG_SWAP
++unsigned long max_swapfile_size(void)
++{
++ unsigned long pages;
++
++ pages = generic_max_swapfile_size();
++
++ if (boot_cpu_has_bug(X86_BUG_L1TF)) {
++ /* Limit the swap file size to MAX_PA/2 for L1TF workaround */
++ unsigned long l1tf_limit = l1tf_pfn_limit() + 1;
++ /*
++ * We encode swap offsets also with 3 bits below those for pfn
++ * which makes the usable limit higher.
++ */
++#if CONFIG_PGTABLE_LEVELS > 2
++ l1tf_limit <<= PAGE_SHIFT - SWP_OFFSET_FIRST_BIT;
++#endif
++ pages = min_t(unsigned long, l1tf_limit, pages);
++ }
++ return pages;
++}
++#endif
+diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
+index 7c8686709636..79eb55ce69a9 100644
+--- a/arch/x86/mm/kmmio.c
++++ b/arch/x86/mm/kmmio.c
+@@ -126,24 +126,29 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long addr)
+
+ static void clear_pmd_presence(pmd_t *pmd, bool clear, pmdval_t *old)
+ {
++ pmd_t new_pmd;
+ pmdval_t v = pmd_val(*pmd);
+ if (clear) {
+- *old = v & _PAGE_PRESENT;
+- v &= ~_PAGE_PRESENT;
+- } else /* presume this has been called with clear==true previously */
+- v |= *old;
+- set_pmd(pmd, __pmd(v));
++ *old = v;
++ new_pmd = pmd_mknotpresent(*pmd);
++ } else {
++ /* Presume this has been called with clear==true previously */
++ new_pmd = __pmd(*old);
++ }
++ set_pmd(pmd, new_pmd);
+ }
+
+ static void clear_pte_presence(pte_t *pte, bool clear, pteval_t *old)
+ {
+ pteval_t v = pte_val(*pte);
+ if (clear) {
+- *old = v & _PAGE_PRESENT;
+- v &= ~_PAGE_PRESENT;
+- } else /* presume this has been called with clear==true previously */
+- v |= *old;
+- set_pte_atomic(pte, __pte(v));
++ *old = v;
++ /* Nothing should care about address */
++ pte_clear(&init_mm, 0, pte);
++ } else {
++ /* Presume this has been called with clear==true previously */
++ set_pte_atomic(pte, __pte(*old));
++ }
+ }
+
+ static int clear_page_presence(struct kmmio_fault_page *f, bool clear)
+diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
+index 48c591251600..f40ab8185d94 100644
+--- a/arch/x86/mm/mmap.c
++++ b/arch/x86/mm/mmap.c
+@@ -240,3 +240,24 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t count)
+
+ return phys_addr_valid(addr + count - 1);
+ }
++
++/*
++ * Only allow root to set high MMIO mappings to PROT_NONE.
++ * This prevents an unpriv. user to set them to PROT_NONE and invert
++ * them, then pointing to valid memory for L1TF speculation.
++ *
++ * Note: for locked down kernels may want to disable the root override.
++ */
++bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
++{
++ if (!boot_cpu_has_bug(X86_BUG_L1TF))
++ return true;
++ if (!__pte_needs_invert(pgprot_val(prot)))
++ return true;
++ /* If it's real memory always allow */
++ if (pfn_valid(pfn))
++ return true;
++ if (pfn > l1tf_pfn_limit() && !capable(CAP_SYS_ADMIN))
++ return false;
++ return true;
++}
+diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
+index 3bded76e8d5c..7bb6f65c79de 100644
+--- a/arch/x86/mm/pageattr.c
++++ b/arch/x86/mm/pageattr.c
+@@ -1014,8 +1014,8 @@ static long populate_pmd(struct cpa_data *cpa,
+
+ pmd = pmd_offset(pud, start);
+
+- set_pmd(pmd, __pmd(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
+- massage_pgprot(pmd_pgprot)));
++ set_pmd(pmd, pmd_mkhuge(pfn_pmd(cpa->pfn,
++ canon_pgprot(pmd_pgprot))));
+
+ start += PMD_SIZE;
+ cpa->pfn += PMD_SIZE >> PAGE_SHIFT;
+@@ -1087,8 +1087,8 @@ static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d,
+ * Map everything starting from the Gb boundary, possibly with 1G pages
+ */
+ while (boot_cpu_has(X86_FEATURE_GBPAGES) && end - start >= PUD_SIZE) {
+- set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
+- massage_pgprot(pud_pgprot)));
++ set_pud(pud, pud_mkhuge(pfn_pud(cpa->pfn,
++ canon_pgprot(pud_pgprot))));
+
+ start += PUD_SIZE;
+ cpa->pfn += PUD_SIZE >> PAGE_SHIFT;
+diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
+index 4d418e705878..fb752d9a3ce9 100644
+--- a/arch/x86/mm/pti.c
++++ b/arch/x86/mm/pti.c
+@@ -45,6 +45,7 @@
+ #include <asm/pgalloc.h>
+ #include <asm/tlbflush.h>
+ #include <asm/desc.h>
++#include <asm/sections.h>
+
+ #undef pr_fmt
+ #define pr_fmt(fmt) "Kernel/User page tables isolation: " fmt
+diff --git a/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c b/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
+index 4f5fa65a1011..2acd6be13375 100644
+--- a/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
++++ b/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
+@@ -18,6 +18,7 @@
+ #include <asm/intel-mid.h>
+ #include <asm/intel_scu_ipc.h>
+ #include <asm/io_apic.h>
++#include <asm/hw_irq.h>
+
+ #define TANGIER_EXT_TIMER0_MSI 12
+
+diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
+index ca446da48fd2..3866b96a7ee7 100644
+--- a/arch/x86/platform/uv/tlb_uv.c
++++ b/arch/x86/platform/uv/tlb_uv.c
+@@ -1285,6 +1285,7 @@ void uv_bau_message_interrupt(struct pt_regs *regs)
+ struct msg_desc msgdesc;
+
+ ack_APIC_irq();
++ kvm_set_cpu_l1tf_flush_l1d();
+ time_start = get_cycles();
+
+ bcp = &per_cpu(bau_control, smp_processor_id());
+diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
+index 3b5318505c69..2eeddd814653 100644
+--- a/arch/x86/xen/enlighten.c
++++ b/arch/x86/xen/enlighten.c
+@@ -3,6 +3,7 @@
+ #endif
+ #include <linux/cpu.h>
+ #include <linux/kexec.h>
++#include <linux/slab.h>
+
+ #include <xen/features.h>
+ #include <xen/page.h>
+diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
+index 30cc9c877ebb..eb9443d5bae1 100644
+--- a/drivers/base/cpu.c
++++ b/drivers/base/cpu.c
+@@ -540,16 +540,24 @@ ssize_t __weak cpu_show_spec_store_bypass(struct device *dev,
+ return sprintf(buf, "Not affected\n");
+ }
+
++ssize_t __weak cpu_show_l1tf(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ return sprintf(buf, "Not affected\n");
++}
++
+ static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
+ static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
+ static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
+ static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
++static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
+
+ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
+ &dev_attr_meltdown.attr,
+ &dev_attr_spectre_v1.attr,
+ &dev_attr_spectre_v2.attr,
+ &dev_attr_spec_store_bypass.attr,
++ &dev_attr_l1tf.attr,
+ NULL
+ };
+
+diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
+index dc87797db500..b50b74053664 100644
+--- a/drivers/gpu/drm/i915/i915_pmu.c
++++ b/drivers/gpu/drm/i915/i915_pmu.c
+@@ -4,6 +4,7 @@
+ * Copyright © 2017-2018 Intel Corporation
+ */
+
++#include <linux/irq.h>
+ #include "i915_pmu.h"
+ #include "intel_ringbuffer.h"
+ #include "i915_drv.h"
+diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
+index 6269750e2b54..b4941101f21a 100644
+--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
++++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
+@@ -62,6 +62,7 @@
+
+ #include <linux/acpi.h>
+ #include <linux/device.h>
++#include <linux/irq.h>
+ #include <linux/pci.h>
+ #include <linux/pm_runtime.h>
+
+diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
+index f6325f1a89e8..d4d4a55f09f8 100644
+--- a/drivers/pci/controller/pci-hyperv.c
++++ b/drivers/pci/controller/pci-hyperv.c
+@@ -45,6 +45,7 @@
+ #include <linux/irqdomain.h>
+ #include <asm/irqdomain.h>
+ #include <asm/apic.h>
++#include <linux/irq.h>
+ #include <linux/msi.h>
+ #include <linux/hyperv.h>
+ #include <linux/refcount.h>
+diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
+index f59639afaa39..26ca0276b503 100644
+--- a/include/asm-generic/pgtable.h
++++ b/include/asm-generic/pgtable.h
+@@ -1083,6 +1083,18 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+ static inline void init_espfix_bsp(void) { }
+ #endif
+
++#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
++static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
++{
++ return true;
++}
++
++static inline bool arch_has_pfn_modify_check(void)
++{
++ return false;
++}
++#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
++
+ #endif /* !__ASSEMBLY__ */
+
+ #ifndef io_remap_pfn_range
+diff --git a/include/linux/cpu.h b/include/linux/cpu.h
+index 3233fbe23594..45789a892c41 100644
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -55,6 +55,8 @@ extern ssize_t cpu_show_spectre_v2(struct device *dev,
+ struct device_attribute *attr, char *buf);
+ extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
+ struct device_attribute *attr, char *buf);
++extern ssize_t cpu_show_l1tf(struct device *dev,
++ struct device_attribute *attr, char *buf);
+
+ extern __printf(4, 5)
+ struct device *cpu_device_create(struct device *parent, void *drvdata,
+@@ -166,4 +168,23 @@ void cpuhp_report_idle_dead(void);
+ static inline void cpuhp_report_idle_dead(void) { }
+ #endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
++enum cpuhp_smt_control {
++ CPU_SMT_ENABLED,
++ CPU_SMT_DISABLED,
++ CPU_SMT_FORCE_DISABLED,
++ CPU_SMT_NOT_SUPPORTED,
++};
++
++#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
++extern enum cpuhp_smt_control cpu_smt_control;
++extern void cpu_smt_disable(bool force);
++extern void cpu_smt_check_topology_early(void);
++extern void cpu_smt_check_topology(void);
++#else
++# define cpu_smt_control (CPU_SMT_ENABLED)
++static inline void cpu_smt_disable(bool force) { }
++static inline void cpu_smt_check_topology_early(void) { }
++static inline void cpu_smt_check_topology(void) { }
++#endif
++
+ #endif /* _LINUX_CPU_H_ */
+diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h
+index 06bd7b096167..e06febf62978 100644
+--- a/include/linux/swapfile.h
++++ b/include/linux/swapfile.h
+@@ -10,5 +10,7 @@ extern spinlock_t swap_lock;
+ extern struct plist_head swap_active_head;
+ extern struct swap_info_struct *swap_info[];
+ extern int try_to_unuse(unsigned int, bool, unsigned long);
++extern unsigned long generic_max_swapfile_size(void);
++extern unsigned long max_swapfile_size(void);
+
+ #endif /* _LINUX_SWAPFILE_H */
+diff --git a/kernel/cpu.c b/kernel/cpu.c
+index 2f8f338e77cf..f80afc674f02 100644
+--- a/kernel/cpu.c
++++ b/kernel/cpu.c
+@@ -60,6 +60,7 @@ struct cpuhp_cpu_state {
+ bool rollback;
+ bool single;
+ bool bringup;
++ bool booted_once;
+ struct hlist_node *node;
+ struct hlist_node *last;
+ enum cpuhp_state cb_state;
+@@ -342,6 +343,85 @@ void cpu_hotplug_enable(void)
+ EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
+ #endif /* CONFIG_HOTPLUG_CPU */
+
++#ifdef CONFIG_HOTPLUG_SMT
++enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED;
++EXPORT_SYMBOL_GPL(cpu_smt_control);
++
++static bool cpu_smt_available __read_mostly;
++
++void __init cpu_smt_disable(bool force)
++{
++ if (cpu_smt_control == CPU_SMT_FORCE_DISABLED ||
++ cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
++ return;
++
++ if (force) {
++ pr_info("SMT: Force disabled\n");
++ cpu_smt_control = CPU_SMT_FORCE_DISABLED;
++ } else {
++ cpu_smt_control = CPU_SMT_DISABLED;
++ }
++}
++
++/*
++ * The decision whether SMT is supported can only be done after the full
++ * CPU identification. Called from architecture code before non boot CPUs
++ * are brought up.
++ */
++void __init cpu_smt_check_topology_early(void)
++{
++ if (!topology_smt_supported())
++ cpu_smt_control = CPU_SMT_NOT_SUPPORTED;
++}
++
++/*
++ * If SMT was disabled by BIOS, detect it here, after the CPUs have been
++ * brought online. This ensures the smt/l1tf sysfs entries are consistent
++ * with reality. cpu_smt_available is set to true during the bringup of non
++ * boot CPUs when a SMT sibling is detected. Note, this may overwrite
++ * cpu_smt_control's previous setting.
++ */
++void __init cpu_smt_check_topology(void)
++{
++ if (!cpu_smt_available)
++ cpu_smt_control = CPU_SMT_NOT_SUPPORTED;
++}
++
++static int __init smt_cmdline_disable(char *str)
++{
++ cpu_smt_disable(str && !strcmp(str, "force"));
++ return 0;
++}
++early_param("nosmt", smt_cmdline_disable);
++
++static inline bool cpu_smt_allowed(unsigned int cpu)
++{
++ if (topology_is_primary_thread(cpu))
++ return true;
++
++ /*
++ * If the CPU is not a 'primary' thread and the booted_once bit is
++ * set then the processor has SMT support. Store this information
++ * for the late check of SMT support in cpu_smt_check_topology().
++ */
++ if (per_cpu(cpuhp_state, cpu).booted_once)
++ cpu_smt_available = true;
++
++ if (cpu_smt_control == CPU_SMT_ENABLED)
++ return true;
++
++ /*
++ * On x86 it's required to boot all logical CPUs at least once so
++ * that the init code can get a chance to set CR4.MCE on each
++ * CPU. Otherwise, a broadacasted MCE observing CR4.MCE=0b on any
++ * core will shutdown the machine.
++ */
++ return !per_cpu(cpuhp_state, cpu).booted_once;
++}
++#else
++static inline bool cpu_smt_allowed(unsigned int cpu) { return true; }
++#endif
++
+ static inline enum cpuhp_state
+ cpuhp_set_state(struct cpuhp_cpu_state *st, enum cpuhp_state target)
+ {
+@@ -422,6 +502,16 @@ static int bringup_wait_for_ap(unsigned int cpu)
+ stop_machine_unpark(cpu);
+ kthread_unpark(st->thread);
+
++ /*
++ * SMT soft disabling on X86 requires to bring the CPU out of the
++ * BIOS 'wait for SIPI' state in order to set the CR4.MCE bit. The
++ * CPU marked itself as booted_once in cpu_notify_starting() so the
++ * cpu_smt_allowed() check will now return false if this is not the
++ * primary sibling.
++ */
++ if (!cpu_smt_allowed(cpu))
++ return -ECANCELED;
++
+ if (st->target <= CPUHP_AP_ONLINE_IDLE)
+ return 0;
+
+@@ -754,7 +844,6 @@ static int takedown_cpu(unsigned int cpu)
+
+ /* Park the smpboot threads */
+ kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
+- smpboot_park_threads(cpu);
+
+ /*
+ * Prevent irq alloc/free while the dying cpu reorganizes the
+@@ -907,20 +996,19 @@ out:
+ return ret;
+ }
+
++static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
++{
++ if (cpu_hotplug_disabled)
++ return -EBUSY;
++ return _cpu_down(cpu, 0, target);
++}
++
+ static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
+ {
+ int err;
+
+ cpu_maps_update_begin();
+-
+- if (cpu_hotplug_disabled) {
+- err = -EBUSY;
+- goto out;
+- }
+-
+- err = _cpu_down(cpu, 0, target);
+-
+-out:
++ err = cpu_down_maps_locked(cpu, target);
+ cpu_maps_update_done();
+ return err;
+ }
+@@ -949,6 +1037,7 @@ void notify_cpu_starting(unsigned int cpu)
+ int ret;
+
+ rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */
++ st->booted_once = true;
+ while (st->state < target) {
+ st->state++;
+ ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
+@@ -1058,6 +1147,10 @@ static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
+ err = -EBUSY;
+ goto out;
+ }
++ if (!cpu_smt_allowed(cpu)) {
++ err = -EPERM;
++ goto out;
++ }
+
+ err = _cpu_up(cpu, 0, target);
+ out:
+@@ -1332,7 +1425,7 @@ static struct cpuhp_step cpuhp_hp_states[] = {
+ [CPUHP_AP_SMPBOOT_THREADS] = {
+ .name = "smpboot/threads:online",
+ .startup.single = smpboot_unpark_threads,
+- .teardown.single = NULL,
++ .teardown.single = smpboot_park_threads,
+ },
+ [CPUHP_AP_IRQ_AFFINITY_ONLINE] = {
+ .name = "irq/affinity:online",
+@@ -1906,10 +1999,172 @@ static const struct attribute_group cpuhp_cpu_root_attr_group = {
+ NULL
+ };
+
++#ifdef CONFIG_HOTPLUG_SMT
++
++static const char *smt_states[] = {
++ [CPU_SMT_ENABLED] = "on",
++ [CPU_SMT_DISABLED] = "off",
++ [CPU_SMT_FORCE_DISABLED] = "forceoff",
++ [CPU_SMT_NOT_SUPPORTED] = "notsupported",
++};
++
++static ssize_t
++show_smt_control(struct device *dev, struct device_attribute *attr, char *buf)
++{
++ return snprintf(buf, PAGE_SIZE - 2, "%s\n", smt_states[cpu_smt_control]);
++}
++
++static void cpuhp_offline_cpu_device(unsigned int cpu)
++{
++ struct device *dev = get_cpu_device(cpu);
++
++ dev->offline = true;
++ /* Tell user space about the state change */
++ kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
++}
++
++static void cpuhp_online_cpu_device(unsigned int cpu)
++{
++ struct device *dev = get_cpu_device(cpu);
++
++ dev->offline = false;
++ /* Tell user space about the state change */
++ kobject_uevent(&dev->kobj, KOBJ_ONLINE);
++}
++
++static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
++{
++ int cpu, ret = 0;
++
++ cpu_maps_update_begin();
++ for_each_online_cpu(cpu) {
++ if (topology_is_primary_thread(cpu))
++ continue;
++ ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
++ if (ret)
++ break;
++ /*
++ * As this needs to hold the cpu maps lock it's impossible
++ * to call device_offline() because that ends up calling
++ * cpu_down() which takes cpu maps lock. cpu maps lock
++ * needs to be held as this might race against in kernel
++ * abusers of the hotplug machinery (thermal management).
++ *
++ * So nothing would update device:offline state. That would
++ * leave the sysfs entry stale and prevent onlining after
++ * smt control has been changed to 'off' again. This is
++ * called under the sysfs hotplug lock, so it is properly
++ * serialized against the regular offline usage.
++ */
++ cpuhp_offline_cpu_device(cpu);
++ }
++ if (!ret)
++ cpu_smt_control = ctrlval;
++ cpu_maps_update_done();
++ return ret;
++}
++
++static int cpuhp_smt_enable(void)
++{
++ int cpu, ret = 0;
++
++ cpu_maps_update_begin();
++ cpu_smt_control = CPU_SMT_ENABLED;
++ for_each_present_cpu(cpu) {
++ /* Skip online CPUs and CPUs on offline nodes */
++ if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
++ continue;
++ ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
++ if (ret)
++ break;
++ /* See comment in cpuhp_smt_disable() */
++ cpuhp_online_cpu_device(cpu);
++ }
++ cpu_maps_update_done();
++ return ret;
++}
++
++static ssize_t
++store_smt_control(struct device *dev, struct device_attribute *attr,
++ const char *buf, size_t count)
++{
++ int ctrlval, ret;
++
++ if (sysfs_streq(buf, "on"))
++ ctrlval = CPU_SMT_ENABLED;
++ else if (sysfs_streq(buf, "off"))
++ ctrlval = CPU_SMT_DISABLED;
++ else if (sysfs_streq(buf, "forceoff"))
++ ctrlval = CPU_SMT_FORCE_DISABLED;
++ else
++ return -EINVAL;
++
++ if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
++ return -EPERM;
++
++ if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
++ return -ENODEV;
++
++ ret = lock_device_hotplug_sysfs();
++ if (ret)
++ return ret;
++
++ if (ctrlval != cpu_smt_control) {
++ switch (ctrlval) {
++ case CPU_SMT_ENABLED:
++ ret = cpuhp_smt_enable();
++ break;
++ case CPU_SMT_DISABLED:
++ case CPU_SMT_FORCE_DISABLED:
++ ret = cpuhp_smt_disable(ctrlval);
++ break;
++ }
++ }
++
++ unlock_device_hotplug();
++ return ret ? ret : count;
++}
++static DEVICE_ATTR(control, 0644, show_smt_control, store_smt_control);
++
++static ssize_t
++show_smt_active(struct device *dev, struct device_attribute *attr, char *buf)
++{
++ bool active = topology_max_smt_threads() > 1;
++
++ return snprintf(buf, PAGE_SIZE - 2, "%d\n", active);
++}
++static DEVICE_ATTR(active, 0444, show_smt_active, NULL);
++
++static struct attribute *cpuhp_smt_attrs[] = {
++ &dev_attr_control.attr,
++ &dev_attr_active.attr,
++ NULL
++};
++
++static const struct attribute_group cpuhp_smt_attr_group = {
++ .attrs = cpuhp_smt_attrs,
++ .name = "smt",
++ NULL
++};
++
++static int __init cpu_smt_state_init(void)
++{
++ return sysfs_create_group(&cpu_subsys.dev_root->kobj,
++ &cpuhp_smt_attr_group);
++}
++
++#else
++static inline int cpu_smt_state_init(void) { return 0; }
++#endif
++
+ static int __init cpuhp_sysfs_init(void)
+ {
+ int cpu, ret;
+
++ ret = cpu_smt_state_init();
++ if (ret)
++ return ret;
++
+ ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
+ &cpuhp_cpu_root_attr_group);
+ if (ret)
+@@ -2012,5 +2267,8 @@ void __init boot_cpu_init(void)
+ */
+ void __init boot_cpu_hotplug_init(void)
+ {
+- per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
++#ifdef CONFIG_SMP
++ this_cpu_write(cpuhp_state.booted_once, true);
++#endif
++ this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);
+ }
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index fe365c9a08e9..5ba96d9ddbde 100644
+--- a/kernel/sched/core.c
++++ b/kernel/sched/core.c
+@@ -5774,6 +5774,18 @@ int sched_cpu_activate(unsigned int cpu)
+ struct rq *rq = cpu_rq(cpu);
+ struct rq_flags rf;
+
++#ifdef CONFIG_SCHED_SMT
++ /*
++ * The sched_smt_present static key needs to be evaluated on every
++ * hotplug event because at boot time SMT might be disabled when
++ * the number of booted CPUs is limited.
++ *
++ * If then later a sibling gets hotplugged, then the key would stay
++ * off and SMT scheduling would never be functional.
++ */
++ if (cpumask_weight(cpu_smt_mask(cpu)) > 1)
++ static_branch_enable_cpuslocked(&sched_smt_present);
++#endif
+ set_cpu_active(cpu, true);
+
+ if (sched_smp_initialized) {
+@@ -5871,22 +5883,6 @@ int sched_cpu_dying(unsigned int cpu)
+ }
+ #endif
+
+-#ifdef CONFIG_SCHED_SMT
+-DEFINE_STATIC_KEY_FALSE(sched_smt_present);
+-
+-static void sched_init_smt(void)
+-{
+- /*
+- * We've enumerated all CPUs and will assume that if any CPU
+- * has SMT siblings, CPU0 will too.
+- */
+- if (cpumask_weight(cpu_smt_mask(0)) > 1)
+- static_branch_enable(&sched_smt_present);
+-}
+-#else
+-static inline void sched_init_smt(void) { }
+-#endif
+-
+ void __init sched_init_smp(void)
+ {
+ sched_init_numa();
+@@ -5908,8 +5904,6 @@ void __init sched_init_smp(void)
+ init_sched_rt_class();
+ init_sched_dl_class();
+
+- sched_init_smt();
+-
+ sched_smp_initialized = true;
+ }
+
+diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
+index 2f0a0be4d344..9c219f7b0970 100644
+--- a/kernel/sched/fair.c
++++ b/kernel/sched/fair.c
+@@ -6237,6 +6237,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
+ }
+
+ #ifdef CONFIG_SCHED_SMT
++DEFINE_STATIC_KEY_FALSE(sched_smt_present);
+
+ static inline void set_idle_cores(int cpu, int val)
+ {
+diff --git a/kernel/smp.c b/kernel/smp.c
+index 084c8b3a2681..d86eec5f51c1 100644
+--- a/kernel/smp.c
++++ b/kernel/smp.c
+@@ -584,6 +584,8 @@ void __init smp_init(void)
+ num_nodes, (num_nodes > 1 ? "s" : ""),
+ num_cpus, (num_cpus > 1 ? "s" : ""));
+
++ /* Final decision about SMT support */
++ cpu_smt_check_topology();
+ /* Any cleanup work */
+ smp_cpus_done(setup_max_cpus);
+ }
+diff --git a/mm/memory.c b/mm/memory.c
+index c5e87a3a82ba..0e356dd923c2 100644
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -1884,6 +1884,9 @@ int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+
++ if (!pfn_modify_allowed(pfn, pgprot))
++ return -EACCES;
++
+ track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV));
+
+ ret = insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
+@@ -1919,6 +1922,9 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
+
+ track_pfn_insert(vma, &pgprot, pfn);
+
++ if (!pfn_modify_allowed(pfn_t_to_pfn(pfn), pgprot))
++ return -EACCES;
++
+ /*
+ * If we don't have pte special, then we have to use the pfn_valid()
+ * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
+@@ -1980,6 +1986,7 @@ static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ {
+ pte_t *pte;
+ spinlock_t *ptl;
++ int err = 0;
+
+ pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+ if (!pte)
+@@ -1987,12 +1994,16 @@ static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ arch_enter_lazy_mmu_mode();
+ do {
+ BUG_ON(!pte_none(*pte));
++ if (!pfn_modify_allowed(pfn, prot)) {
++ err = -EACCES;
++ break;
++ }
+ set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot)));
+ pfn++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(pte - 1, ptl);
+- return 0;
++ return err;
+ }
+
+ static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
+@@ -2001,6 +2012,7 @@ static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
+ {
+ pmd_t *pmd;
+ unsigned long next;
++ int err;
+
+ pfn -= addr >> PAGE_SHIFT;
+ pmd = pmd_alloc(mm, pud, addr);
+@@ -2009,9 +2021,10 @@ static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ do {
+ next = pmd_addr_end(addr, end);
+- if (remap_pte_range(mm, pmd, addr, next,
+- pfn + (addr >> PAGE_SHIFT), prot))
+- return -ENOMEM;
++ err = remap_pte_range(mm, pmd, addr, next,
++ pfn + (addr >> PAGE_SHIFT), prot);
++ if (err)
++ return err;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+ }
+@@ -2022,6 +2035,7 @@ static inline int remap_pud_range(struct mm_struct *mm, p4d_t *p4d,
+ {
+ pud_t *pud;
+ unsigned long next;
++ int err;
+
+ pfn -= addr >> PAGE_SHIFT;
+ pud = pud_alloc(mm, p4d, addr);
+@@ -2029,9 +2043,10 @@ static inline int remap_pud_range(struct mm_struct *mm, p4d_t *p4d,
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+- if (remap_pmd_range(mm, pud, addr, next,
+- pfn + (addr >> PAGE_SHIFT), prot))
+- return -ENOMEM;
++ err = remap_pmd_range(mm, pud, addr, next,
++ pfn + (addr >> PAGE_SHIFT), prot);
++ if (err)
++ return err;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+ }
+@@ -2042,6 +2057,7 @@ static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd,
+ {
+ p4d_t *p4d;
+ unsigned long next;
++ int err;
+
+ pfn -= addr >> PAGE_SHIFT;
+ p4d = p4d_alloc(mm, pgd, addr);
+@@ -2049,9 +2065,10 @@ static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd,
+ return -ENOMEM;
+ do {
+ next = p4d_addr_end(addr, end);
+- if (remap_pud_range(mm, p4d, addr, next,
+- pfn + (addr >> PAGE_SHIFT), prot))
+- return -ENOMEM;
++ err = remap_pud_range(mm, p4d, addr, next,
++ pfn + (addr >> PAGE_SHIFT), prot);
++ if (err)
++ return err;
+ } while (p4d++, addr = next, addr != end);
+ return 0;
+ }
+diff --git a/mm/mprotect.c b/mm/mprotect.c
+index 625608bc8962..6d331620b9e5 100644
+--- a/mm/mprotect.c
++++ b/mm/mprotect.c
+@@ -306,6 +306,42 @@ unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
+ return pages;
+ }
+
++static int prot_none_pte_entry(pte_t *pte, unsigned long addr,
++ unsigned long next, struct mm_walk *walk)
++{
++ return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ?
++ 0 : -EACCES;
++}
++
++static int prot_none_hugetlb_entry(pte_t *pte, unsigned long hmask,
++ unsigned long addr, unsigned long next,
++ struct mm_walk *walk)
++{
++ return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ?
++ 0 : -EACCES;
++}
++
++static int prot_none_test(unsigned long addr, unsigned long next,
++ struct mm_walk *walk)
++{
++ return 0;
++}
++
++static int prot_none_walk(struct vm_area_struct *vma, unsigned long start,
++ unsigned long end, unsigned long newflags)
++{
++ pgprot_t new_pgprot = vm_get_page_prot(newflags);
++ struct mm_walk prot_none_walk = {
++ .pte_entry = prot_none_pte_entry,
++ .hugetlb_entry = prot_none_hugetlb_entry,
++ .test_walk = prot_none_test,
++ .mm = current->mm,
++ .private = &new_pgprot,
++ };
++
++ return walk_page_range(start, end, &prot_none_walk);
++}
++
+ int
+ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
+ unsigned long start, unsigned long end, unsigned long newflags)
+@@ -323,6 +359,19 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
+ return 0;
+ }
+
++ /*
++ * Do PROT_NONE PFN permission checks here when we can still
++ * bail out without undoing a lot of state. This is a rather
++ * uncommon case, so doesn't need to be very optimized.
++ */
++ if (arch_has_pfn_modify_check() &&
++ (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
++ (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) {
++ error = prot_none_walk(vma, start, end, newflags);
++ if (error)
++ return error;
++ }
++
+ /*
+ * If we make a private mapping writable we increase our commit;
+ * but (without finer accounting) cannot reduce our commit if we
+diff --git a/mm/swapfile.c b/mm/swapfile.c
+index 2cc2972eedaf..18185ae4f223 100644
+--- a/mm/swapfile.c
++++ b/mm/swapfile.c
+@@ -2909,6 +2909,35 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
+ return 0;
+ }
+
++
++/*
++ * Find out how many pages are allowed for a single swap device. There
++ * are two limiting factors:
++ * 1) the number of bits for the swap offset in the swp_entry_t type, and
++ * 2) the number of bits in the swap pte, as defined by the different
++ * architectures.
++ *
++ * In order to find the largest possible bit mask, a swap entry with
++ * swap type 0 and swap offset ~0UL is created, encoded to a swap pte,
++ * decoded to a swp_entry_t again, and finally the swap offset is
++ * extracted.
++ *
++ * This will mask all the bits from the initial ~0UL mask that can't
++ * be encoded in either the swp_entry_t or the architecture definition
++ * of a swap pte.
++ */
++unsigned long generic_max_swapfile_size(void)
++{
++ return swp_offset(pte_to_swp_entry(
++ swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
++}
++
++/* Can be overridden by an architecture for additional checks. */
++__weak unsigned long max_swapfile_size(void)
++{
++ return generic_max_swapfile_size();
++}
++
+ static unsigned long read_swap_header(struct swap_info_struct *p,
+ union swap_header *swap_header,
+ struct inode *inode)
+@@ -2944,22 +2973,7 @@ static unsigned long read_swap_header(struct swap_info_struct *p,
+ p->cluster_next = 1;
+ p->cluster_nr = 0;
+
+- /*
+- * Find out how many pages are allowed for a single swap
+- * device. There are two limiting factors: 1) the number
+- * of bits for the swap offset in the swp_entry_t type, and
+- * 2) the number of bits in the swap pte as defined by the
+- * different architectures. In order to find the
+- * largest possible bit mask, a swap entry with swap type 0
+- * and swap offset ~0UL is created, encoded to a swap pte,
+- * decoded to a swp_entry_t again, and finally the swap
+- * offset is extracted. This will mask all the bits from
+- * the initial ~0UL mask that can't be encoded in either
+- * the swp_entry_t or the architecture definition of a
+- * swap pte.
+- */
+- maxpages = swp_offset(pte_to_swp_entry(
+- swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
++ maxpages = max_swapfile_size();
+ last_page = swap_header->info.last_page;
+ if (!last_page) {
+ pr_warn("Empty swap-file\n");
+diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
+index 5701f5cecd31..64aaa3f5f36c 100644
+--- a/tools/arch/x86/include/asm/cpufeatures.h
++++ b/tools/arch/x86/include/asm/cpufeatures.h
+@@ -219,6 +219,7 @@
+ #define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */
+ #define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */
+ #define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
++#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
+
+ /* Virtualization flags: Linux defined, word 8 */
+ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
+@@ -341,6 +342,7 @@
+ #define X86_FEATURE_PCONFIG (18*32+18) /* Intel PCONFIG */
+ #define X86_FEATURE_SPEC_CTRL (18*32+26) /* "" Speculation Control (IBRS + IBPB) */
+ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */
++#define X86_FEATURE_FLUSH_L1D (18*32+28) /* Flush L1D cache */
+ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
+ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */
+
+@@ -373,5 +375,6 @@
+ #define X86_BUG_SPECTRE_V1 X86_BUG(15) /* CPU is affected by Spectre variant 1 attack with conditional branches */
+ #define X86_BUG_SPECTRE_V2 X86_BUG(16) /* CPU is affected by Spectre variant 2 attack with indirect branches */
+ #define X86_BUG_SPEC_STORE_BYPASS X86_BUG(17) /* CPU is affected by speculative store bypass attack */
++#define X86_BUG_L1TF X86_BUG(18) /* CPU is affected by L1 Terminal Fault */
+
+ #endif /* _ASM_X86_CPUFEATURES_H */
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