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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2025-08-14 10:20:43 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2025-08-14 10:38:18 -0700 |
| commit | b7cc9887231526ca4fa89f3fa4119e47c2dc7b1e (patch) | |
| tree | 515fb05671f3c725228463ae988c790aa43e1982 /arch/x86/kernel/cpu/common.c | |
| parent | x86/bugs: Move cpu_bugs_smt_update() down (diff) | |
| download | linux-b7cc9887231526ca4fa89f3fa4119e47c2dc7b1e.tar.gz linux-b7cc9887231526ca4fa89f3fa4119e47c2dc7b1e.zip | |
x86/vmscape: Warn when STIBP is disabled with SMT
Cross-thread attacks are generally harder as they require the victim to be
co-located on a core. However, with VMSCAPE the adversary targets belong to
the same guest execution, that are more likely to get co-located. In
particular, a thread that is currently executing userspace hypervisor
(after the IBPB) may still be targeted by a guest execution from a sibling
thread.
Issue a warning about the potential risk, except when:
- SMT is disabled
- STIBP is enabled system-wide
- Intel eIBRS is enabled (which implies STIBP protection)
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
0 files changed, 0 insertions, 0 deletions