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authorVineela Tummalapalli <vineela.tummalapalli@intel.com>2019-11-04 14:22:01 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-12 21:19:03 +0300
commit56a0f3867c1bc40c6f155c780a284cc881a89488 (patch)
treecb43e368b81326b6a2b8be8849c8c7136cd1062e /Documentation
parent9b81a067dcfcdc2411338fcc110d90c412c92c76 (diff)
downloadlinux-56a0f3867c1bc40c6f155c780a284cc881a89488.tar.xz
x86/bugs: Add ITLB_MULTIHIT bug infrastructure
commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 0fffc1c66da1..9ebca6a750f3 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -382,6 +382,7 @@ 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