Re: [PATCH 2/2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state

2017-01-30 Thread Yu-cheng Yu
On Wed, Jan 25, 2017 at 08:57:59PM -0500, r...@redhat.com wrote: > From: Rik van Riel > > 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

Re: [PATCH 2/2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state

2017-01-26 Thread Dave Hansen
On 01/25/2017 05:57 PM, r...@redhat.com wrote: > /* > + * Restoring SSE/YMM state requires that MXCSR & MXCSR_MASK are saved. > + * Those fields are part of the legacy FP state, and only get saved > + * above if XFEATURES_MASK_FP is set. > + * > + * Copy out those fie

Re: [PATCH 2/2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state

2017-01-26 Thread Ingo Molnar
* r...@redhat.com wrote: > From: Rik van Riel > > 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 rea

[PATCH 2/2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state

2017-01-25 Thread riel
From: Rik van Riel 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