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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V6 1/2] x86/xsaves: calculate the comp_offsets base on xcomp_bv
Previous patch using all available features calculate comp_offsets.
This is wrong.This patch fix this bug by calculating the comp_offset
based on xcomp_bv of current guest.
Also, the comp_offset should take alignment into consideration.
Signed-off-by: Shuai Ruan <shuai.ruan@xxxxxxxxxxxxxxx>
Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
---
V5: Address comments from Jan:
1. use xcomp_bv to caculate comp_offsets
2. local variable/funciton parameters with no xstate_ prefix
3. fix a bug realted with test_bit().
V4: Address comments from Jan:
1. use xstate_comp_offsets as on-stack array.
V3: Address comments from Jan:
1. fix xstate_comp_offsets used as static array problem.
2. change xstate_align from array to u64 and used as bitmap.
3. change calculating xstate_comp_offsets into three step.
1) whether component is set in xsavearea
2) whether component need align
3) add xstate_size[i-1]
V2: Address comments from Jan:
1. code style fix.
2. setup_xstate_comp take xcomp_bv as param.
xen/arch/x86/xstate.c | 58 ++++++++++++++++++++++++++++----------------
xen/include/asm-x86/xstate.h | 2 ++
2 files changed, 39 insertions(+), 21 deletions(-)
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index f649405..a7b6a04 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -26,8 +26,8 @@ u64 __read_mostly xfeature_mask;
static unsigned int *__read_mostly xstate_offsets;
unsigned int *__read_mostly xstate_sizes;
+static u64 __read_mostly xstate_align;
static unsigned int __read_mostly xstate_features;
-static unsigned int __read_mostly xstate_comp_offsets[sizeof(xfeature_mask)*8];
static uint32_t __read_mostly mxcsr_mask = 0x0000ffbf;
@@ -94,7 +94,7 @@ static bool_t xsave_area_compressed(const struct xsave_struct
*xsave_area)
static int setup_xstate_features(bool_t bsp)
{
- unsigned int leaf, tmp, eax, ebx;
+ unsigned int leaf, eax, ebx, ecx, edx;
if ( bsp )
{
@@ -111,57 +111,71 @@ static int setup_xstate_features(bool_t bsp)
for ( leaf = 2; leaf < xstate_features; leaf++ )
{
if ( bsp )
+ {
cpuid_count(XSTATE_CPUID, leaf, &xstate_sizes[leaf],
- &xstate_offsets[leaf], &tmp, &tmp);
+ &xstate_offsets[leaf], &ecx, &edx);
+ if ( ecx & XSTATE_ALIGN64 )
+ __set_bit(leaf, &xstate_align);
+ }
else
{
cpuid_count(XSTATE_CPUID, leaf, &eax,
- &ebx, &tmp, &tmp);
+ &ebx, &ecx, &edx);
BUG_ON(eax != xstate_sizes[leaf]);
BUG_ON(ebx != xstate_offsets[leaf]);
+ BUG_ON(!(ecx & XSTATE_ALIGN64) != !test_bit(leaf, &xstate_align));
}
}
return 0;
}
-static void __init setup_xstate_comp(void)
+static void setup_xstate_comp(uint16_t *comp_offsets,
+ const uint64_t xcomp_bv)
{
unsigned int i;
+ unsigned int offset;
/*
* The FP xstates and SSE xstates are legacy states. They are always
* in the fixed offsets in the xsave area in either compacted form
* or standard form.
*/
- xstate_comp_offsets[0] = 0;
- xstate_comp_offsets[1] = XSAVE_SSE_OFFSET;
+ comp_offsets[0] = 0;
+ comp_offsets[1] = XSAVE_SSE_OFFSET;
- xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+ comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
- for ( i = 3; i < xstate_features; i++ )
+ offset = comp_offsets[2];
+ for ( i = 2; i < xstate_features; i++ )
{
- xstate_comp_offsets[i] = xstate_comp_offsets[i - 1] +
- (((1ul << i) & xfeature_mask)
- ? xstate_sizes[i - 1] : 0);
- ASSERT(xstate_comp_offsets[i] + xstate_sizes[i] <= xsave_cntxt_size);
+ if ( (1ul << i) & xcomp_bv )
+ {
+ if ( test_bit(i, &xstate_align) )
+ offset = ROUNDUP(offset, 64);
+ comp_offsets[i] = offset;
+ offset += xstate_sizes[i];
+ }
}
+ ASSERT(offset <= xsave_cntxt_size);
}
static void *get_xsave_addr(struct xsave_struct *xsave,
- unsigned int xfeature_idx)
+ const uint16_t *comp_offsets,
+ unsigned int xfeature_idx)
{
if ( !((1ul << xfeature_idx) & xsave->xsave_hdr.xstate_bv) )
return NULL;
- return (void *)xsave + (xsave_area_compressed(xsave)
- ? xstate_comp_offsets
- : xstate_offsets)[xfeature_idx];
+ return (void *)xsave + (xsave_area_compressed(xsave) ?
+ comp_offsets[xfeature_idx] :
+ xstate_offsets[xfeature_idx]);
}
void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
{
struct xsave_struct *xsave = v->arch.xsave_area;
+ uint16_t comp_offsets[sizeof(xfeature_mask)*8];
u64 xstate_bv = xsave->xsave_hdr.xstate_bv;
u64 valid;
@@ -172,6 +186,8 @@ void expand_xsave_states(struct vcpu *v, void *dest,
unsigned int size)
}
ASSERT(xsave_area_compressed(xsave));
+ setup_xstate_comp(comp_offsets, xsave->xsave_hdr.xcomp_bv);
+
/*
* Copy legacy XSAVE area and XSAVE hdr area.
*/
@@ -188,7 +204,7 @@ void expand_xsave_states(struct vcpu *v, void *dest,
unsigned int size)
{
u64 feature = valid & -valid;
unsigned int index = fls(feature) - 1;
- const void *src = get_xsave_addr(xsave, index);
+ const void *src = get_xsave_addr(xsave, comp_offsets, index);
if ( src )
{
@@ -203,6 +219,7 @@ void expand_xsave_states(struct vcpu *v, void *dest,
unsigned int size)
void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
{
struct xsave_struct *xsave = v->arch.xsave_area;
+ uint16_t comp_offsets[sizeof(xfeature_mask)*8];
u64 xstate_bv = ((const struct xsave_struct *)src)->xsave_hdr.xstate_bv;
u64 valid;
@@ -222,6 +239,7 @@ void compress_xsave_states(struct vcpu *v, const void *src,
unsigned int size)
/* Set XSTATE_BV and XCOMP_BV. */
xsave->xsave_hdr.xstate_bv = xstate_bv;
xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
+ setup_xstate_comp(comp_offsets, xsave->xsave_hdr.xcomp_bv);
/*
* Copy each region from the non-compacted offset to the
@@ -232,7 +250,7 @@ void compress_xsave_states(struct vcpu *v, const void *src,
unsigned int size)
{
u64 feature = valid & -valid;
unsigned int index = fls(feature) - 1;
- void *dest = get_xsave_addr(xsave, index);
+ void *dest = get_xsave_addr(xsave, comp_offsets, index);
if ( dest )
{
@@ -564,8 +582,6 @@ void xstate_init(struct cpuinfo_x86 *c)
if ( setup_xstate_features(bsp) && bsp )
BUG();
- if ( bsp && (cpu_has_xsaves || cpu_has_xsavec) )
- setup_xstate_comp();
}
static bool_t valid_xcr0(u64 xcr0)
diff --git a/xen/include/asm-x86/xstate.h b/xen/include/asm-x86/xstate.h
index c28cea5..a488688 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -46,6 +46,8 @@
#define XSTATE_LAZY (XSTATE_ALL & ~XSTATE_NONLAZY)
#define XSTATE_COMPACTION_ENABLED (1ULL << 63)
+#define XSTATE_ALIGN64 (1U << 1)
+
extern u64 xfeature_mask;
extern unsigned int *xstate_sizes;
--
1.9.1
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