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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [V9 1/3] x86/xsaves: enable xsaves/xrstors/xsavec in xen
This patch uses xsaves/xrstors/xsavec instead of xsaveopt/xrstor
to perform the xsave_area switching so that xen itself
can benefit from them when available.
For xsaves/xrstors/xsavec only use compact format. Add format conversion
support when perform guest os migration.
Also, pv guest will not support xsaves/xrstors.
Signed-off-by: Shuai Ruan <shuai.ruan@xxxxxxxxxxxxxxx>
---
xen/arch/x86/domain.c | 7 ++
xen/arch/x86/domctl.c | 30 +++++-
xen/arch/x86/hvm/hvm.c | 18 +++-
xen/arch/x86/i387.c | 4 +
xen/arch/x86/traps.c | 6 +-
xen/arch/x86/xstate.c | 242 +++++++++++++++++++++++++++++++++++++------
xen/include/asm-x86/xstate.h | 2 +
7 files changed, 265 insertions(+), 44 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index fe3be30..108d4f8 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -883,7 +883,12 @@ 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 || cpu_has_xsavec )
+ v->arch.xsave_area->xsave_hdr.xcomp_bv = XSTATE_FP_SSE |
+
XSTATE_COMPACTION_ENABLED;
+ }
}
if ( !compat )
@@ -1568,6 +1573,8 @@ static void __context_switch(void)
if ( xcr0 != get_xcr0() && !set_xcr0(xcr0) )
BUG();
}
+ if ( cpu_has_xsaves && has_hvm_container_vcpu(n) )
+ set_msr_xss(n->arch.hvm_vcpu.msr_xss);
vcpu_restore_fpu_eager(n);
n->arch.ctxt_switch_to(n);
}
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 0f6fdb9..95b0747 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -897,9 +897,29 @@ long arch_do_domctl(
ret = -EFAULT;
offset += sizeof(v->arch.xcr0_accum);
- if ( !ret && copy_to_guest_offset(evc->buffer, offset,
- (void *)v->arch.xsave_area,
- size - 2 * sizeof(uint64_t)) )
+ if ( !ret && (cpu_has_xsaves || cpu_has_xsavec) )
+ {
+ void *xsave_area;
+
+ xsave_area = xmalloc_bytes(size);
+ if ( !xsave_area )
+ {
+ ret = -ENOMEM;
+ vcpu_unpause(v);
+ goto vcpuextstate_out;
+ }
+
+ expand_xsave_states(v, xsave_area,
+ size - 2 * sizeof(uint64_t));
+
+ if ( copy_to_guest_offset(evc->buffer, offset, xsave_area,
+ size - 2 * sizeof(uint64_t)) )
+ ret = -EFAULT;
+ xfree(xsave_area);
+ }
+ else if ( !ret && copy_to_guest_offset(evc->buffer, offset,
+ (void *)v->arch.xsave_area,
+ size - 2 * sizeof(uint64_t))
)
ret = -EFAULT;
vcpu_unpause(v);
@@ -955,8 +975,8 @@ long arch_do_domctl(
v->arch.xcr0_accum = _xcr0_accum;
if ( _xcr0_accum & XSTATE_NONLAZY )
v->arch.nonlazy_xstate_used = 1;
- memcpy(v->arch.xsave_area, _xsave_area,
- evc->size - 2 * sizeof(uint64_t));
+ compress_xsave_states(v, _xsave_area,
+ evc->size - 2 * sizeof(uint64_t));
vcpu_unpause(v);
}
else
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 21f42a7..dd86730 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2090,6 +2090,9 @@ static int hvm_load_cpu_ctxt(struct domain *d,
hvm_domain_context_t *h)
memcpy(v->arch.xsave_area, ctxt.fpu_regs, sizeof(ctxt.fpu_regs));
xsave_area->xsave_hdr.xstate_bv = XSTATE_FP_SSE;
+ if ( cpu_has_xsaves || cpu_has_xsavec )
+ xsave_area->xsave_hdr.xcomp_bv = XSTATE_FP_SSE |
+ XSTATE_COMPACTION_ENABLED;
}
else
memcpy(v->arch.fpu_ctxt, ctxt.fpu_regs, sizeof(ctxt.fpu_regs));
@@ -2159,8 +2162,8 @@ 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));
+ expand_xsave_states(v, &ctxt->save_area,
+ size - offsetof(typeof(*ctxt), save_area));
}
return 0;
@@ -2259,9 +2262,9 @@ 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));
+ compress_xsave_states(v, &ctxt->save_area,
+ min(desc->length, size) -
+ offsetof(struct hvm_hw_cpu_xsave,save_area));
return 0;
}
@@ -5458,7 +5461,12 @@ void hvm_vcpu_reset_state(struct vcpu *v, uint16_t cs,
uint16_t ip)
fpu_ctxt->fcw = FCW_RESET;
fpu_ctxt->mxcsr = MXCSR_DEFAULT;
if ( v->arch.xsave_area )
+ {
v->arch.xsave_area->xsave_hdr.xstate_bv = XSTATE_FP;
+ if ( cpu_has_xsaves || cpu_has_xsavec )
+ v->arch.xsave_area->xsave_hdr.xcomp_bv = XSTATE_FP |
+ XSTATE_COMPACTION_ENABLED;
+ }
v->arch.vgc_flags = VGCF_online;
memset(&v->arch.user_regs, 0, sizeof(v->arch.user_regs));
diff --git a/xen/arch/x86/i387.c b/xen/arch/x86/i387.c
index 66b51cb..b661d39 100644
--- a/xen/arch/x86/i387.c
+++ b/xen/arch/x86/i387.c
@@ -282,7 +282,11 @@ int vcpu_init_fpu(struct vcpu *v)
return rc;
if ( v->arch.xsave_area )
+ {
v->arch.fpu_ctxt = &v->arch.xsave_area->fpu_sse;
+ if ( cpu_has_xsaves || cpu_has_xsavec )
+ v->arch.xsave_area->xsave_hdr.xcomp_bv = XSTATE_COMPACTION_ENABLED;
+ }
else
{
v->arch.fpu_ctxt = _xzalloc(sizeof(v->arch.xsave_area->fpu_sse), 16);
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index b32f696..9063314 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -935,9 +935,9 @@ void pv_cpuid(struct cpu_user_regs *regs)
goto unsupported;
if ( regs->_ecx == 1 )
{
- a &=
boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_XSAVEOPT)];
- if ( !cpu_has_xsaves )
- b = c = d = 0;
+ a &=
(boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_XSAVEOPT)] &
+ ~cpufeat_mask(X86_FEATURE_XSAVES));
+ b = c = d = 0;
}
break;
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index 827e0e1..ada40ff 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -24,6 +24,11 @@ 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 * __read_mostly xstate_offsets;
+static unsigned int * __read_mostly xstate_sizes;
+static unsigned int __read_mostly xstate_features;
+static unsigned int __read_mostly xstate_comp_offsets[sizeof(xfeature_mask)*8];
+
/* Cached xcr0 for fast read */
static DEFINE_PER_CPU(uint64_t, xcr0);
@@ -79,6 +84,161 @@ uint64_t get_msr_xss(void)
return this_cpu(xss);
}
+static bool_t xsave_area_compressed(const struct xsave_struct *xsave_area)
+{
+ return xsave_area && (xsave_area->xsave_hdr.xcomp_bv
+ & XSTATE_COMPACTION_ENABLED);
+}
+
+static int setup_xstate_features(bool_t bsp)
+{
+ unsigned int leaf, tmp, eax, ebx;
+
+ if ( bsp )
+ {
+ xstate_features = fls(xfeature_mask);
+ xstate_offsets = xzalloc_array(unsigned int, xstate_features);
+ if ( !xstate_offsets )
+ return -ENOMEM;
+
+ xstate_sizes = xzalloc_array(unsigned int, xstate_features);
+ if ( !xstate_sizes )
+ return -ENOMEM;
+ }
+
+ for ( leaf = 2; leaf < xstate_features; leaf++ )
+ {
+ if ( bsp )
+ cpuid_count(XSTATE_CPUID, leaf, &xstate_sizes[leaf],
+ &xstate_offsets[leaf], &tmp, &tmp);
+ else
+ {
+ cpuid_count(XSTATE_CPUID, leaf, &eax,
+ &ebx, &tmp, &tmp);
+ BUG_ON(eax != xstate_sizes[leaf]);
+ BUG_ON(ebx != xstate_offsets[leaf]);
+ }
+ }
+
+ return 0;
+}
+
+static void __init setup_xstate_comp(void)
+{
+ unsigned 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 = 3; 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);
+ }
+}
+
+static void *get_xsave_addr(void *xsave, unsigned int xfeature_idx)
+{
+ if ( !((1ul << xfeature_idx) & xfeature_mask) )
+ return NULL;
+
+ return xsave + xstate_comp_offsets[xfeature_idx];
+}
+
+void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
+{
+ struct xsave_struct *xsave = v->arch.xsave_area;
+ u64 xstate_bv = xsave->xsave_hdr.xstate_bv;
+ u64 valid;
+
+ if ( !cpu_has_xsaves && !cpu_has_xsavec )
+ {
+ memcpy(dest, xsave, size);
+ return;
+ }
+
+ ASSERT(xsave_area_compressed(xsave));
+ /*
+ * Copy legacy XSAVE area and XSAVE hdr area.
+ */
+ memcpy(dest, xsave, XSTATE_AREA_MIN_SIZE);
+
+ ((struct xsave_struct *)dest)->xsave_hdr.xcomp_bv = 0;
+
+ /*
+ * 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;
+ unsigned int index = fls(feature) - 1;
+ const void *src = get_xsave_addr(xsave, index);
+
+ if ( src )
+ {
+ ASSERT((xstate_offsets[index] + xstate_sizes[index]) <= size);
+ memcpy(dest + xstate_offsets[index], src, xstate_sizes[index]);
+ }
+
+ valid &= ~feature;
+ }
+}
+
+void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
+{
+ struct xsave_struct *xsave = v->arch.xsave_area;
+ u64 xstate_bv = ((const struct xsave_struct *)src)->xsave_hdr.xstate_bv;
+ u64 valid;
+
+ if ( !cpu_has_xsaves && !cpu_has_xsavec )
+ {
+ memcpy(xsave, src, size);
+ return;
+ }
+
+ ASSERT(!xsave_area_compressed(src));
+ /*
+ * Copy legacy XSAVE area, to avoid complications with CPUID
+ * leaves 0 and 1 in the loop below.
+ */
+ memcpy(xsave, src, FXSAVE_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;
+
+ /*
+ * 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;
+ unsigned int index = fls(feature) - 1;
+ void *dest = get_xsave_addr(xsave, index);
+
+ if ( dest )
+ {
+ ASSERT((xstate_offsets[index] + xstate_sizes[index]) <= size);
+ memcpy(dest, src + xstate_offsets[index], xstate_sizes[index]);
+ }
+
+ valid &= ~feature;
+ }
+}
+
void xsave(struct vcpu *v, uint64_t mask)
{
struct xsave_struct *ptr = v->arch.xsave_area;
@@ -91,7 +251,15 @@ void xsave(struct vcpu *v, uint64_t mask)
typeof(ptr->fpu_sse.fip.sel) fcs = ptr->fpu_sse.fip.sel;
typeof(ptr->fpu_sse.fdp.sel) fds = ptr->fpu_sse.fdp.sel;
- if ( cpu_has_xsaveopt )
+ if ( cpu_has_xsaves )
+ asm volatile ( ".byte 0x48,0x0f,0xc7,0x2f"
+ : "=m" (*ptr)
+ : "a" (lmask), "d" (hmask), "D" (ptr) );
+ else if ( cpu_has_xsavec )
+ asm volatile ( ".byte 0x48,0x0f,0xc7,0x27"
+ : "=m" (*ptr)
+ : "a" (lmask), "d" (hmask), "D" (ptr) );
+ else if ( cpu_has_xsaveopt )
{
/*
* xsaveopt may not write the FPU portion even when the respective
@@ -144,7 +312,15 @@ void xsave(struct vcpu *v, uint64_t mask)
}
else
{
- if ( cpu_has_xsaveopt )
+ if ( cpu_has_xsaves )
+ asm volatile ( ".byte 0x0f,0xc7,0x2f"
+ : "=m" (*ptr)
+ : "a" (lmask), "d" (hmask), "D" (ptr) );
+ else if ( cpu_has_xsavec )
+ asm volatile ( ".byte 0x0f,0xc7,0x27"
+ : "=m" (*ptr)
+ : "a" (lmask), "d" (hmask), "D" (ptr) );
+ else if ( cpu_has_xsaveopt )
asm volatile ( ".byte 0x0f,0xae,0x37"
: "=m" (*ptr)
: "a" (lmask), "d" (hmask), "D" (ptr) );
@@ -158,6 +334,20 @@ void xsave(struct vcpu *v, uint64_t mask)
ptr->fpu_sse.x[FPU_WORD_SIZE_OFFSET] = word_size;
}
+#define XSTATE_FIXUP ".section .fixup,\"ax\" \n" \
+ "2: mov %5,%%ecx \n" \
+ " xor %1,%1 \n" \
+ " rep stosb \n" \
+ " lea %2,%0 \n" \
+ " mov %3,%1 \n" \
+ " jmp 1b \n" \
+ ".previous \n" \
+ _ASM_EXTABLE(1b, 2b) \
+ : "+&D" (ptr), "+&a" (lmask) \
+ : "m" (*ptr), "g" (lmask), "d" (hmask), \
+ "m" (xsave_cntxt_size) \
+ : "ecx"
+
void xrstor(struct vcpu *v, uint64_t mask)
{
uint32_t hmask = mask >> 32;
@@ -187,39 +377,22 @@ void xrstor(struct vcpu *v, uint64_t mask)
switch ( __builtin_expect(ptr->fpu_sse.x[FPU_WORD_SIZE_OFFSET], 8) )
{
default:
- asm volatile ( "1: .byte 0x48,0x0f,0xae,0x2f\n"
- ".section .fixup,\"ax\" \n"
- "2: mov %5,%%ecx \n"
- " xor %1,%1 \n"
- " rep stosb \n"
- " lea %2,%0 \n"
- " mov %3,%1 \n"
- " jmp 1b \n"
- ".previous \n"
- _ASM_EXTABLE(1b, 2b)
- : "+&D" (ptr), "+&a" (lmask)
- : "m" (*ptr), "g" (lmask), "d" (hmask),
- "m" (xsave_cntxt_size)
- : "ecx" );
+ alternative_input("1: "".byte 0x48,0x0f,0xae,0x2f",
+ ".byte 0x48,0x0f,0xc7,0x1f",
+ X86_FEATURE_XSAVES,
+ "D" (ptr), "m" (*ptr), "a" (lmask), "d" (hmask));
+ asm volatile (XSTATE_FIXUP);
break;
case 4: case 2:
- asm volatile ( "1: .byte 0x0f,0xae,0x2f\n"
- ".section .fixup,\"ax\" \n"
- "2: mov %5,%%ecx \n"
- " xor %1,%1 \n"
- " rep stosb \n"
- " lea %2,%0 \n"
- " mov %3,%1 \n"
- " jmp 1b \n"
- ".previous \n"
- _ASM_EXTABLE(1b, 2b)
- : "+&D" (ptr), "+&a" (lmask)
- : "m" (*ptr), "g" (lmask), "d" (hmask),
- "m" (xsave_cntxt_size)
- : "ecx" );
+ alternative_input("1: "".byte 0x0f,0xae,0x2f",
+ ".byte 0x0f,0xc7,0x1f",
+ X86_FEATURE_XSAVES,
+ "D" (ptr), "m" (*ptr), "a" (lmask), "d" (hmask));
+ asm volatile (XSTATE_FIXUP);
break;
}
}
+#undef XSTATE_FIXUP
bool_t xsave_enabled(const struct vcpu *v)
{
@@ -343,11 +516,18 @@ void xstate_init(struct cpuinfo_x86 *c)
/* Mask out features not currently understood by Xen. */
eax &= (cpufeat_mask(X86_FEATURE_XSAVEOPT) |
- cpufeat_mask(X86_FEATURE_XSAVEC));
+ cpufeat_mask(X86_FEATURE_XSAVEC) |
+ cpufeat_mask(X86_FEATURE_XGETBV1) |
+ cpufeat_mask(X86_FEATURE_XSAVES));
c->x86_capability[cpufeat_word(X86_FEATURE_XSAVEOPT)] = eax;
BUG_ON(eax !=
boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_XSAVEOPT)]);
+
+ 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 b95a5b5..414cc99 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -91,6 +91,8 @@ void xrstor(struct vcpu *v, uint64_t mask);
bool_t xsave_enabled(const struct vcpu *v);
int __must_check validate_xstate(u64 xcr0, u64 xcr0_accum, u64 xstate_bv);
int __must_check handle_xsetbv(u32 index, u64 new_bv);
+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);
/* extended state init and cleanup functions */
void xstate_free_save_area(struct vcpu *v);
--
1.9.1
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