Wei Huang
2011-Feb-04 17:49 UTC
[Xen-devel] [PATCH][HVM] fix XSAVE leaf 0 EBX size calculation
Fixes a size calculation bug when enabled bits in XFEATURE_MASK (xcr0) aren''t contiguous. Current for_loop will stop when xcr0 feature bit is 0. But in reality, the bits can be non-contiguous. One example is that LWP is bit 62 on AMD platform. This patch iterates through all bits to calculate the size for enabled features. Signed-off-by: Wei Huang <wei.huang2@amd.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Wei, Gang
2011-Feb-09 05:32 UTC
[Xen-devel] [PATCH] x86: reduce magic number usage in XSAVE code (RE: [PATCH][HVM] fix XSAVE leaf 0 EBX size calculation)
Wei Huang wrote on 2011-02-05:> Fixes a size calculation bug when enabled bits in XFEATURE_MASK (xcr0) > aren't contiguous. > > Current for_loop will stop when xcr0 feature bit is 0. But in reality, > the bits can be non-contiguous. One example is that LWP is bit 62 on > AMD platform. This patch iterates through all bits to calculate the size for enabled features. > > Signed-off-by: Wei Huang <wei.huang2@amd.com>ACK on the patch despite it was checked in already. BTW, I want to add a trivial patch to limit the magic number usage in XSAVE code. x86: reduce magic number usage in XSAVE code Signed-off-by: Wei Gang <gang.wei@intel.com> diff -r aeda4adecaf8 xen/arch/x86/hvm/hvm.c --- a/xen/arch/x86/hvm/hvm.c Tue Feb 08 16:35:35 2011 +0000 +++ b/xen/arch/x86/hvm/hvm.c Thu Feb 10 19:12:29 2011 +0800 @@ -2223,7 +2223,7 @@ void hvm_cpuid(unsigned int input, unsig if ( count == 0 && v->arch.xcr0 ) { /* reset EBX to default value first */ - *ebx = 576; + *ebx = XSAVE_AREA_MIN_SIZE; for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ ) { if ( !(v->arch.xcr0 & (1ULL << sub_leaf)) ) diff -r aeda4adecaf8 xen/arch/x86/i387.c --- a/xen/arch/x86/i387.c Tue Feb 08 16:35:35 2011 +0000 +++ b/xen/arch/x86/i387.c Thu Feb 10 19:14:02 2011 +0800 @@ -221,7 +221,6 @@ static void restore_fpu(struct vcpu *v) } #define XSTATE_CPUID 0xd -#define XSAVE_AREA_MIN_SIZE (512 + 64) /* FP/SSE + XSAVE.HEADER */ /* * Maximum size (in byte) of the XSAVE/XRSTOR save area required by all diff -r aeda4adecaf8 xen/include/asm-x86/i387.h --- a/xen/include/asm-x86/i387.h Tue Feb 08 16:35:35 2011 +0000 +++ b/xen/include/asm-x86/i387.h Thu Feb 10 19:11:37 2011 +0800 @@ -21,13 +21,14 @@ int xsave_alloc_save_area(struct vcpu *v int xsave_alloc_save_area(struct vcpu *v); void xsave_free_save_area(struct vcpu *v); +#define XSAVE_AREA_MIN_SIZE (512 + 64) /* FP/SSE + XSAVE.HEADER */ #define XSTATE_FP (1ULL << 0) #define XSTATE_SSE (1ULL << 1) #define XSTATE_YMM (1ULL << 2) #define XSTATE_LWP (1ULL << 62) /* AMD lightweight profiling */ #define XSTATE_FP_SSE (XSTATE_FP | XSTATE_SSE) #define XCNTXT_MASK (XSTATE_FP | XSTATE_SSE | XSTATE_YMM | XSTATE_LWP) -#define XSTATE_YMM_OFFSET (512 + 64) +#define XSTATE_YMM_OFFSET XSAVE_AREA_MIN_SIZE #define XSTATE_YMM_SIZE 256 #define XSAVEOPT (1 << 0) Jimmy _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Wei Huang
2011-Feb-09 16:41 UTC
[Xen-devel] Re: [PATCH] x86: reduce magic number usage in XSAVE code (RE: [PATCH][HVM] fix XSAVE leaf 0 EBX size calculation)
Acked-by: Wei Huang <wei.huang2@amd.com> On 02/08/2011 11:32 PM, Wei, Gang wrote:> Wei Huang wrote on 2011-02-05: >> Fixes a size calculation bug when enabled bits in XFEATURE_MASK (xcr0) >> aren''t contiguous. >> >> Current for_loop will stop when xcr0 feature bit is 0. But in reality, >> the bits can be non-contiguous. One example is that LWP is bit 62 on >> AMD platform. This patch iterates through all bits to calculate the size for enabled features. >> >> Signed-off-by: Wei Huang<wei.huang2@amd.com> > ACK on the patch despite it was checked in already. BTW, I want to add a trivial patch to limit the magic number usage in XSAVE code. > > x86: reduce magic number usage in XSAVE code > > Signed-off-by: Wei Gang<gang.wei@intel.com> > > diff -r aeda4adecaf8 xen/arch/x86/hvm/hvm.c > --- a/xen/arch/x86/hvm/hvm.c Tue Feb 08 16:35:35 2011 +0000 > +++ b/xen/arch/x86/hvm/hvm.c Thu Feb 10 19:12:29 2011 +0800 > @@ -2223,7 +2223,7 @@ void hvm_cpuid(unsigned int input, unsig > if ( count == 0&& v->arch.xcr0 ) > { > /* reset EBX to default value first */ > - *ebx = 576; > + *ebx = XSAVE_AREA_MIN_SIZE; > for ( sub_leaf = 2; sub_leaf< 64; sub_leaf++ ) > { > if ( !(v->arch.xcr0& (1ULL<< sub_leaf)) ) > diff -r aeda4adecaf8 xen/arch/x86/i387.c > --- a/xen/arch/x86/i387.c Tue Feb 08 16:35:35 2011 +0000 > +++ b/xen/arch/x86/i387.c Thu Feb 10 19:14:02 2011 +0800 > @@ -221,7 +221,6 @@ static void restore_fpu(struct vcpu *v) > } > > #define XSTATE_CPUID 0xd > -#define XSAVE_AREA_MIN_SIZE (512 + 64) /* FP/SSE + XSAVE.HEADER */ > > /* > * Maximum size (in byte) of the XSAVE/XRSTOR save area required by all > diff -r aeda4adecaf8 xen/include/asm-x86/i387.h > --- a/xen/include/asm-x86/i387.h Tue Feb 08 16:35:35 2011 +0000 > +++ b/xen/include/asm-x86/i387.h Thu Feb 10 19:11:37 2011 +0800 > @@ -21,13 +21,14 @@ int xsave_alloc_save_area(struct vcpu *v > int xsave_alloc_save_area(struct vcpu *v); > void xsave_free_save_area(struct vcpu *v); > > +#define XSAVE_AREA_MIN_SIZE (512 + 64) /* FP/SSE + XSAVE.HEADER */ > #define XSTATE_FP (1ULL<< 0) > #define XSTATE_SSE (1ULL<< 1) > #define XSTATE_YMM (1ULL<< 2) > #define XSTATE_LWP (1ULL<< 62) /* AMD lightweight profiling */ > #define XSTATE_FP_SSE (XSTATE_FP | XSTATE_SSE) > #define XCNTXT_MASK (XSTATE_FP | XSTATE_SSE | XSTATE_YMM | XSTATE_LWP) > -#define XSTATE_YMM_OFFSET (512 + 64) > +#define XSTATE_YMM_OFFSET XSAVE_AREA_MIN_SIZE > #define XSTATE_YMM_SIZE 256 > #define XSAVEOPT (1<< 0) > > > Jimmy_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel