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| author |   Rik van Riel <riel@redhat.com> | 2017-09-23 15:00:04 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-09-24 13:04:34 +0200 |
| commit | 0852b374173bb57f870d78e6c6839c77b339be5f (patch) | |
| tree | 5dc1a0236423ee5b4708d534a7cbb7fd898d2bbc /arch/x86/include/asm/fpu/types.h | |
| parent | x86/fpu: Remove struct fpu::fpregs_active (diff) | |
| download | linux-dev-0852b374173bb57f870d78e6c6839c77b339be5f.tar.xz linux-dev-0852b374173bb57f870d78e6c6839c77b339be5f.zip | |
x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel Skylake CPUs
On Skylake CPUs I noticed that XRSTOR is unable to deal with states
created by copyout_from_xsaves() if the xstate has only SSE/YMM state, and
no FP state. That is, xfeatures had XFEATURE_MASK_SSE set, but not
XFEATURE_MASK_FP.
The reason is that part of the SSE/YMM state lives in the MXCSR and
MXCSR_FLAGS fields of the FP state.
Ensure that whenever we copy SSE or YMM state around, the MXCSR and
MXCSR_FLAGS fields are also copied around.
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170210085445.0f1cc708@annuminas.surriel.com
Link: http://lkml.kernel.org/r/20170923130016.21448-22-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/fpu/types.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 0c314a397cf5..71db45ca8870 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -68,6 +68,9 @@ struct fxregs_state { /* Default value for fxregs_state.mxcsr: */ #define MXCSR_DEFAULT 0x1f80 +/* Copy both mxcsr & mxcsr_flags with a single u64 memcpy: */ +#define MXCSR_AND_FLAGS_SIZE sizeof(u64) + /* * Software based FPU emulation state. This is arbitrary really, * it matches the x87 format to make it easier to understand: |