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authorVineela Tummalapalli <vineela.tummalapalli@intel.com>2019-11-04 12:22:01 +0100
committerThomas Gleixner <tglx@linutronix.de>2019-11-04 12:22:01 +0100
commitdb4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae (patch)
tree3159a64521ee62ee31d9af775a7e31eb4c8f2e48 /Documentation
parentca8888d7ae6fa18454c9e4f192c56bc6c8ca9b33 (diff)
downloadlinux-db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae.tar.bz2
x86/bugs: Add ITLB_MULTIHIT bug infrastructure
Some processors may incur a machine check error possibly resulting in an unrecoverable CPU lockup when an instruction fetch encounters a TLB multi-hit in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. The relevant erratum can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=205195 There are other processors affected for which the erratum does not fully disclose the impact. This issue affects both bare-metal x86 page tables and EPT. It can be mitigated by either eliminating the use of large pages or by using careful TLB invalidations when changing the page size in the page tables. Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which are mitigated against this issue. Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com> Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-devices-system-cpu1
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 0e77569bd5e0..fc20cde63d1e 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -487,6 +487,7 @@ What: /sys/devices/system/cpu/vulnerabilities
/sys/devices/system/cpu/vulnerabilities/l1tf
/sys/devices/system/cpu/vulnerabilities/mds
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+ /sys/devices/system/cpu/vulnerabilities/itlb_multihit
Date: January 2018
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Information about CPU vulnerabilities