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@xxxxxxx>
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@xxxxxxxxx>
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
