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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2025-08-14 10:20:42 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-11 17:21:46 +0200 |
| commit | 459274c77b37ac63b78c928b4b4e748d1f9d05c8 (patch) | |
| tree | a5270cd760477bbf24e36e6ff458976c036aae50 /Documentation | |
| parent | d7ddc93392e4a7ffcccc86edf6ef3e64c778db52 (diff) | |
| download | linux-459274c77b37ac63b78c928b4b4e748d1f9d05c8.tar.gz linux-459274c77b37ac63b78c928b4b4e748d1f9d05c8.tar.bz2 linux-459274c77b37ac63b78c928b4b4e748d1f9d05c8.zip | |
x86/vmscape: Enable the mitigation
Commit 556c1ad666ad90c50ec8fccb930dd5046cfbecfb upstream.
Enable the previously added mitigation for VMscape. Add the cmdline
vmscape={off|ibpb|force} and sysfs reporting.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 11 |
2 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 53755b2021ed..28f062dc25e1 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -525,6 +525,7 @@ What: /sys/devices/system/cpu/vulnerabilities /sys/devices/system/cpu/vulnerabilities/srbds /sys/devices/system/cpu/vulnerabilities/tsa /sys/devices/system/cpu/vulnerabilities/tsx_async_abort + /sys/devices/system/cpu/vulnerabilities/vmscape Date: January 2018 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: Information about CPU vulnerabilities diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f402bbaccc8a..8724c2c580b8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3548,6 +3548,7 @@ srbds=off [X86,INTEL] ssbd=force-off [ARM64] tsx_async_abort=off [X86] + vmscape=off [X86] Exceptions: This does not have any effect on @@ -7425,6 +7426,16 @@ vmpoff= [KNL,S390] Perform z/VM CP command after power off. Format: <command> + vmscape= [X86] Controls mitigation for VMscape attacks. + VMscape attacks can leak information from a userspace + hypervisor to a guest via speculative side-channels. + + off - disable the mitigation + ibpb - use Indirect Branch Prediction Barrier + (IBPB) mitigation (default) + force - force vulnerability detection even on + unaffected processors + vsyscall= [X86-64,EARLY] Controls the behavior of vsyscalls (i.e. calls to fixed addresses of 0xffffffffff600x00 from legacy |