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| author | Kim Phillips <kim.phillips@amd.com> | 2024-01-25 22:11:02 -0600 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-01-29 17:19:01 +0100 |
| commit | acaa4b5c4c854b5009f4d4a5395b2609ad0f4937 (patch) | |
| tree | e692d6d999c4ac18a9648ca15aad5ed51e3b39b8 /scripts/gdb/linux/proc.py | |
| parent | b6e0f6666f74f0794530e3557f5b0a4ce37bd556 (diff) | |
x86/speculation: Do not enable Automatic IBRS if SEV-SNP is enabled
Without SEV-SNP, Automatic IBRS protects only the kernel. But when
SEV-SNP is enabled, the Automatic IBRS protection umbrella widens to all
host-side code, including userspace. This protection comes at a cost:
reduced userspace indirect branch performance.
To avoid this performance loss, don't use Automatic IBRS on SEV-SNP
hosts and all back to retpolines instead.
[ mdr: squash in changes from review discussion. ]
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lore.kernel.org/r/20240126041126.1927228-3-michael.roth@amd.com
Diffstat (limited to 'scripts/gdb/linux/proc.py')
0 files changed, 0 insertions, 0 deletions