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| author | Eric Biggers <ebiggers@kernel.org> | 2026-09-01 07:57:34 -0700 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2026-09-05 08:16:47 -0700 |
| commit | 19c5d90800a24096697dd6c66237218b7ea417ee (patch) | |
| tree | e40ac7721b7c808c22a77d04cfe935c2c27a2a31 /tools/perf/scripts/python | |
| parent | 518aa9948e4f2ba69b7066371d3ac8e4d31d604e (diff) | |
um: Check for missing AVX and AVX-512 xstate bits
If the CPU declares AVX or AVX-512 support, verify that all the
corresponding bits are set in the XCR0 register. If any are missing,
warn and don't set the corresponding X86_FEATURE_* flags.
This eliminates the perceived need for UML-supporting AVX and AVX-512
optimized code in the kernel (that is, lib/raid/ currently) to start
checking the XCR0 bits in addition to X86_FEATURE_AVX*.
This aligns UML with the vast majority of userspace programs, which
check the XCR0 bits before considering AVX and AVX-512 to be supported,
as per the procedure documented in Intel's CPU manual.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260901145740.42337-3-ebiggers@kernel.org
Diffstat (limited to 'tools/perf/scripts/python')
0 files changed, 0 insertions, 0 deletions