x86/fpu: Check for missing AVX and AVX-512 xstate bits

If the CPU declares AVX or AVX-512 support, verify that the corresponding
xstate bits are also set.  If not, warn and clear them.

This eliminates the perceived need for AVX and AVX-512 optimized code in the
kernel to call cpu_has_xfeatures().  That has never been universally done,
which strongly suggests that it has never really been needed in practice, but
this should remove any remaining doubt.

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/20260901145740.42337-2-ebiggers@kernel.org

0 files changed, 0 insertions, 0 deletions