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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V3 5/6] x86/xsaves: support compact format for hvm save/restore
xsaves/xrstors only use compact format, so format convertion
is needed when perform save/restore.
Signed-off-by: Shuai Ruan <shuai.ruan@xxxxxxxxxxxxxxx>
---
xen/arch/x86/domain.c | 3 +
xen/arch/x86/hvm/hvm.c | 16 +++--
xen/arch/x86/xstate.c | 138 +++++++++++++++++++++++++++++++++++++++++++
xen/include/asm-x86/xstate.h | 6 ++
4 files changed, 158 insertions(+), 5 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index e8b8d67..083b70d 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -845,6 +845,9 @@ int arch_set_info_guest(
memcpy(v->arch.fpu_ctxt, &c.nat->fpu_ctxt, sizeof(c.nat->fpu_ctxt));
if ( v->arch.xsave_area )
v->arch.xsave_area->xsave_hdr.xstate_bv = XSTATE_FP_SSE;
+ if ( cpu_has_xsaves )
+ v->arch.xsave_area->xsave_hdr.xcomp_bv = v->arch.xcr0_accum |
+ XSTATE_COMPACTION_ENABLED;
}
if ( !compat )
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index e5cf761..8495938 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2127,8 +2127,11 @@ static int hvm_save_cpu_xsave_states(struct domain *d,
hvm_domain_context_t *h)
ctxt->xfeature_mask = xfeature_mask;
ctxt->xcr0 = v->arch.xcr0;
ctxt->xcr0_accum = v->arch.xcr0_accum;
- memcpy(&ctxt->save_area, v->arch.xsave_area,
- size - offsetof(struct hvm_hw_cpu_xsave, save_area));
+ if ( cpu_has_xsaves )
+ save_xsave_states(v, (u8 *)&ctxt->save_area);
+ else
+ memcpy(&ctxt->save_area, v->arch.xsave_area,
+ size - offsetof(struct hvm_hw_cpu_xsave, save_area));
}
return 0;
@@ -2227,9 +2230,12 @@ static int hvm_load_cpu_xsave_states(struct domain *d,
hvm_domain_context_t *h)
v->arch.xcr0_accum = ctxt->xcr0_accum;
if ( ctxt->xcr0_accum & XSTATE_NONLAZY )
v->arch.nonlazy_xstate_used = 1;
- memcpy(v->arch.xsave_area, &ctxt->save_area,
- min(desc->length, size) - offsetof(struct hvm_hw_cpu_xsave,
- save_area));
+ if ( cpu_has_xsaves )
+ load_xsave_states(v, (u8 *)&ctxt->save_area);
+ else
+ memcpy(v->arch.xsave_area, &ctxt->save_area,
+ min(desc->length, size) - offsetof(struct hvm_hw_cpu_xsave,
+ save_area));
return 0;
}
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index 699058d..0eea146 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -29,6 +29,9 @@ static u32 __read_mostly xsave_cntxt_size;
/* A 64-bit bitmask of the XSAVE/XRSTOR features supported by processor. */
u64 __read_mostly xfeature_mask;
+static unsigned int *xstate_offsets, *xstate_sizes;
+static unsigned int xstate_features;
+static unsigned int xstate_comp_offsets[sizeof(xfeature_mask)*8];
/* Cached xcr0 for fast read */
static DEFINE_PER_CPU(uint64_t, xcr0);
@@ -65,6 +68,135 @@ uint64_t get_xcr0(void)
return this_cpu(xcr0);
}
+static void setup_xstate_features(void)
+{
+ unsigned int eax, ebx, ecx, edx, leaf = 0x2;
+
+ xstate_features = fls(xfeature_mask);
+ xstate_offsets = _xzalloc(xstate_features, sizeof(int));
+ xstate_sizes = _xzalloc(xstate_features, sizeof(int));
+
+ do {
+ cpuid_count(XSTATE_CPUID, leaf, &eax, &ebx, &ecx, &edx);
+
+ if ( eax == 0 )
+ break;
+
+ xstate_offsets[leaf] = ebx;
+ xstate_sizes[leaf] = eax;
+
+ leaf++;
+ } while (1);
+}
+
+static void setup_xstate_comp(void)
+{
+ unsigned int xstate_comp_sizes[sizeof(xfeature_mask)*8];
+ int i;
+
+ /*
+ * 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;
+
+ xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+
+ for (i = 2; i < xstate_features; i++)
+ {
+ if ( 1 << i & xfeature_mask )
+ xstate_comp_sizes[i] = xstate_sizes[i];
+ else
+ xstate_comp_sizes[i] = 0;
+
+ if ( i > 2 )
+ xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
+ + xstate_comp_sizes[i-1];
+ }
+}
+
+static void *get_xsave_addr(struct xsave_struct *xsave, int xstate)
+{
+ int feature = fls(xstate) - 1;
+ if ( !(1 << feature & xfeature_mask) )
+ return NULL;
+
+ return (void *)xsave + xstate_comp_offsets[feature];
+}
+
+void save_xsave_states(struct vcpu *v, u8 *dest)
+{
+ struct xsave_struct *xsave = v->arch.xsave_area;
+ u64 xstate_bv = xsave->xsave_hdr.xstate_bv;
+ u64 valid;
+
+ /*
+ * Copy legacy XSAVE area, to avoid complications with CPUID
+ * leaves 0 and 1 in the loop below.
+ */
+ memcpy(dest, xsave, XSAVE_HDR_OFFSET);
+
+ /* Set XSTATE_BV */
+ *(u64 *)(dest + XSAVE_HDR_OFFSET) = xstate_bv;
+
+ /*
+ * Copy each region from the possibly compacted offset to the
+ * non-compacted offset.
+ */
+ valid = xstate_bv & ~XSTATE_FP_SSE;
+ while ( valid )
+ {
+ u64 feature = valid & -valid;
+ int index = fls(feature) - 1;
+ void *src = get_xsave_addr(xsave, feature);
+
+ if ( src )
+ memcpy(dest + xstate_offsets[index], src, xstate_sizes[index]);
+ else
+ WARN_ON(1);
+
+ valid -= feature;
+ }
+}
+
+void load_xsave_states(struct vcpu *v, u8 *src)
+{
+ struct xsave_struct *xsave = v->arch.xsave_area;
+ u64 xstate_bv = *(u64 *)(src + XSAVE_HDR_OFFSET);
+ u64 valid;
+
+ /*
+ * Copy legacy XSAVE area, to avoid complications with CPUID
+ * leaves 0 and 1 in the loop below.
+ */
+ memcpy(xsave, src, XSAVE_HDR_OFFSET);
+
+ /* Set XSTATE_BV and possibly XCOMP_BV. */
+ xsave->xsave_hdr.xstate_bv = xstate_bv;
+ xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
+
+ /*
+ * Copy each region from the non-compacted offset to the
+ * possibly compacted offset.
+ */
+ valid = xstate_bv & ~XSTATE_FP_SSE;
+ while ( valid )
+ {
+ u64 feature = valid & -valid;
+ int index = fls(feature) - 1;
+ void *dest = get_xsave_addr(xsave, feature);
+
+ if (dest)
+ memcpy(dest, src + xstate_offsets[index], xstate_sizes[index]);
+ else
+ WARN_ON(1);
+
+ valid -= feature;
+ }
+}
+
void xsaves(uint32_t lmask, uint32_t hmask, struct xsave_struct *ptr)
{
asm volatile ( ".byte 0x48,0x0f,0xc7,0x2f"
@@ -388,6 +520,12 @@ void xstate_init(bool_t bsp)
/* XXX BUG_ON(!cpu_has_xgetbv1 != !(eax & XSTATE_FEATURE_XGETBV1)); */
/* XXX BUG_ON(!cpu_has_xsaves != !(eax & XSTATE_FEATURE_XSAVES)); */
}
+
+ if ( cpu_has_xsaves )
+ {
+ setup_xstate_features();
+ 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 75fa6eb..454454d 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -22,7 +22,11 @@
#define XCR_XFEATURE_ENABLED_MASK 0x00000000 /* index of XCR0 */
+#define XSAVE_HDR_SIZE 64
+#define XSAVE_SSE_OFFSET 160
#define XSTATE_YMM_SIZE 256
+#define FXSAVE_SIZE 512
+#define XSAVE_HDR_OFFSET FXSAVE_SIZE
#define XSTATE_AREA_MIN_SIZE (512 + 64) /* FP/SSE + XSAVE.HEADER */
#define XSTATE_FP (1ULL << 0)
@@ -86,6 +90,8 @@ bool_t __must_check set_xcr0(u64 xfeatures);
uint64_t get_xcr0(void);
void xsaves(uint32_t lmask, uint32_t hmask, struct xsave_struct *ptr);
void xrstors(uint32_t lmask, uint32_t hmask, struct xsave_struct *ptr);
+void save_xsave_states(struct vcpu *v, u8 *dest);
+void load_xsave_states(struct vcpu *v, u8 *src);
void xsave(struct vcpu *v, uint64_t mask);
void xrstor(struct vcpu *v, uint64_t mask);
bool_t xsave_enabled(const struct vcpu *v);
--
1.9.1
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