mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 19:46:40 +07:00
x86/fpu/xstate: Re-enable XSAVES
We did not handle XSAVES instructions correctly. There were issues in converting between standard and compacted format when interfacing with user-space. These issues have been corrected. Add a WARN_ONCE() to make it clear that XSAVES supervisor states are not yet implemented. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-5-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
parent
35ac2d7ba7
commit
b8be15d588
@ -230,21 +230,6 @@ static void __init fpu__init_system_xstate_size_legacy(void)
|
||||
}
|
||||
|
||||
fpu_user_xstate_size = fpu_kernel_xstate_size;
|
||||
|
||||
/*
|
||||
* Quirk: we don't yet handle the XSAVES* instructions
|
||||
* correctly, as we don't correctly convert between
|
||||
* standard and compacted format when interfacing
|
||||
* with user-space - so disable it for now.
|
||||
*
|
||||
* The difference is small: with recent CPUs the
|
||||
* compacted format is only marginally smaller than
|
||||
* the standard FPU state format.
|
||||
*
|
||||
* ( This is easy to backport while we are fixing
|
||||
* XSAVES* support. )
|
||||
*/
|
||||
setup_clear_cpu_cap(X86_FEATURE_XSAVES);
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -221,6 +221,15 @@ void fpu__init_cpu_xstate(void)
|
||||
{
|
||||
if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask)
|
||||
return;
|
||||
/*
|
||||
* Make it clear that XSAVES supervisor states are not yet
|
||||
* implemented should anyone expect it to work by changing
|
||||
* bits in XFEATURE_MASK_* macros and XCR0.
|
||||
*/
|
||||
WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR),
|
||||
"x86/fpu: XSAVES supervisor states are not yet implemented.\n");
|
||||
|
||||
xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR;
|
||||
|
||||
cr4_set_bits(X86_CR4_OSXSAVE);
|
||||
xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
|
||||
|
Loading…
Reference in New Issue
Block a user