Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
Il 21/01/2014 19:59, Liu, Jinsong ha scritto:
From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001
From: Liu Jinsong
Date: Fri, 13 Dec 2013 02:32:03 +0800
Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable.
Bit 63 of XCR0 is reserved for future expansion.
Signed-off-by: Liu Jinsong
---
arch/x86/include/asm/xsave.h |2 ++
arch/x86/kvm/cpuid.c |6 +++---
arch/x86/kvm/x86.c |7 +--
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 5547389..f6c4e85 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -13,6 +13,8 @@
#define XSTATE_BNDCSR 0x10
#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
+/* Bit 63 of XCR0 is reserved for future expansion */
+#define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1 << 63)))
This should be 1ULL, not 1. The compiler should have warned you.
Paolo
#define FXSAVE_SIZE512
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c697625..2d661e6 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -28,7 +28,7 @@ static u32 xstate_required_size(u64 xstate_bv)
int feature_bit = 0;
u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
- xstate_bv &= ~XSTATE_FPSSE;
+ xstate_bv &= XSTATE_EXTEND_MASK;
while (xstate_bv) {
if (xstate_bv & 0x1) {
u32 eax, ebx, ecx, edx;
@@ -74,8 +74,8 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
vcpu->arch.guest_supported_xcr0 =
(best->eax | ((u64)best->edx << 32)) &
host_xcr0 & KVM_SUPPORTED_XCR0;
- vcpu->arch.guest_xstate_size =
- xstate_required_size(vcpu->arch.guest_supported_xcr0);
+ vcpu->arch.guest_xstate_size = best->ebx =
+ xstate_required_size(vcpu->arch.xcr0);
}
kvm_pmu_cpuid_update(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21ef1ba..1657ca2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -576,13 +576,13 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
- u64 xcr0;
+ u64 xcr0 = xcr;
+ u64 old_xcr0 = vcpu->arch.xcr0;
u64 valid_bits;
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
- xcr0 = xcr;
if (!(xcr0 & XSTATE_FP))
return 1;
if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
kvm_put_guest_xcr0(vcpu);
vcpu->arch.xcr0 = xcr0;
+
+ if ((xcr0 ^ old_xcr0) & XSTATE_EXTEND_MASK)
+ kvm_update_cpuid(vcpu);
return 0;
}
--
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Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
On 01/22/2014 02:21 AM, Paolo Bonzini wrote: > Il 21/01/2014 19:59, Liu, Jinsong ha scritto: >> From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001 >> From: Liu Jinsong >> Date: Fri, 13 Dec 2013 02:32:03 +0800 >> Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug >> >> EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable. >> Bit 63 of XCR0 is reserved for future expansion. >> >> Signed-off-by: Liu Jinsong > > Peter, can I have your acked-by on this? > Yes. Acked-by: H. Peter Anvin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
Il 21/01/2014 19:59, Liu, Jinsong ha scritto:
From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001
From: Liu Jinsong
Date: Fri, 13 Dec 2013 02:32:03 +0800
Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable.
Bit 63 of XCR0 is reserved for future expansion.
Signed-off-by: Liu Jinsong
Peter, can I have your acked-by on this?
---
arch/x86/include/asm/xsave.h |2 ++
arch/x86/kvm/cpuid.c |6 +++---
arch/x86/kvm/x86.c |7 +--
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 5547389..f6c4e85 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -13,6 +13,8 @@
#define XSTATE_BNDCSR 0x10
#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
+/* Bit 63 of XCR0 is reserved for future expansion */
+#define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1 << 63)))
#define FXSAVE_SIZE512
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c697625..2d661e6 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -28,7 +28,7 @@ static u32 xstate_required_size(u64 xstate_bv)
int feature_bit = 0;
u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
- xstate_bv &= ~XSTATE_FPSSE;
+ xstate_bv &= XSTATE_EXTEND_MASK;
while (xstate_bv) {
if (xstate_bv & 0x1) {
u32 eax, ebx, ecx, edx;
@@ -74,8 +74,8 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
vcpu->arch.guest_supported_xcr0 =
(best->eax | ((u64)best->edx << 32)) &
host_xcr0 & KVM_SUPPORTED_XCR0;
- vcpu->arch.guest_xstate_size =
- xstate_required_size(vcpu->arch.guest_supported_xcr0);
+ vcpu->arch.guest_xstate_size = best->ebx =
+ xstate_required_size(vcpu->arch.xcr0);
}
kvm_pmu_cpuid_update(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21ef1ba..1657ca2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -576,13 +576,13 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
- u64 xcr0;
+ u64 xcr0 = xcr;
+ u64 old_xcr0 = vcpu->arch.xcr0;
u64 valid_bits;
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
- xcr0 = xcr;
if (!(xcr0 & XSTATE_FP))
return 1;
if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
kvm_put_guest_xcr0(vcpu);
vcpu->arch.xcr0 = xcr0;
+
+ if ((xcr0 ^ old_xcr0) & XSTATE_EXTEND_MASK)
+ kvm_update_cpuid(vcpu);
return 0;
}
--
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Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
Il 21/01/2014 19:59, Liu, Jinsong ha scritto:
From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001
From: Liu Jinsong jinsong@intel.com
Date: Fri, 13 Dec 2013 02:32:03 +0800
Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable.
Bit 63 of XCR0 is reserved for future expansion.
Signed-off-by: Liu Jinsong jinsong@intel.com
Peter, can I have your acked-by on this?
---
arch/x86/include/asm/xsave.h |2 ++
arch/x86/kvm/cpuid.c |6 +++---
arch/x86/kvm/x86.c |7 +--
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 5547389..f6c4e85 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -13,6 +13,8 @@
#define XSTATE_BNDCSR 0x10
#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
+/* Bit 63 of XCR0 is reserved for future expansion */
+#define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1 63)))
#define FXSAVE_SIZE512
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c697625..2d661e6 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -28,7 +28,7 @@ static u32 xstate_required_size(u64 xstate_bv)
int feature_bit = 0;
u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
- xstate_bv = ~XSTATE_FPSSE;
+ xstate_bv = XSTATE_EXTEND_MASK;
while (xstate_bv) {
if (xstate_bv 0x1) {
u32 eax, ebx, ecx, edx;
@@ -74,8 +74,8 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
vcpu-arch.guest_supported_xcr0 =
(best-eax | ((u64)best-edx 32))
host_xcr0 KVM_SUPPORTED_XCR0;
- vcpu-arch.guest_xstate_size =
- xstate_required_size(vcpu-arch.guest_supported_xcr0);
+ vcpu-arch.guest_xstate_size = best-ebx =
+ xstate_required_size(vcpu-arch.xcr0);
}
kvm_pmu_cpuid_update(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21ef1ba..1657ca2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -576,13 +576,13 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
- u64 xcr0;
+ u64 xcr0 = xcr;
+ u64 old_xcr0 = vcpu-arch.xcr0;
u64 valid_bits;
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
- xcr0 = xcr;
if (!(xcr0 XSTATE_FP))
return 1;
if ((xcr0 XSTATE_YMM) !(xcr0 XSTATE_SSE))
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
kvm_put_guest_xcr0(vcpu);
vcpu-arch.xcr0 = xcr0;
+
+ if ((xcr0 ^ old_xcr0) XSTATE_EXTEND_MASK)
+ kvm_update_cpuid(vcpu);
return 0;
}
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
On 01/22/2014 02:21 AM, Paolo Bonzini wrote: Il 21/01/2014 19:59, Liu, Jinsong ha scritto: From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001 From: Liu Jinsong jinsong@intel.com Date: Fri, 13 Dec 2013 02:32:03 +0800 Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable. Bit 63 of XCR0 is reserved for future expansion. Signed-off-by: Liu Jinsong jinsong@intel.com Peter, can I have your acked-by on this? Yes. Acked-by: H. Peter Anvin h...@linux.intel.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
Il 21/01/2014 19:59, Liu, Jinsong ha scritto:
From 3155a190ce6ebb213e6c724240f4e6620ba67a9d Mon Sep 17 00:00:00 2001
From: Liu Jinsong jinsong@intel.com
Date: Fri, 13 Dec 2013 02:32:03 +0800
Subject: [PATCH v3 1/4] KVM/X86: Fix xsave cpuid exposing bug
EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable.
Bit 63 of XCR0 is reserved for future expansion.
Signed-off-by: Liu Jinsong jinsong@intel.com
---
arch/x86/include/asm/xsave.h |2 ++
arch/x86/kvm/cpuid.c |6 +++---
arch/x86/kvm/x86.c |7 +--
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 5547389..f6c4e85 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -13,6 +13,8 @@
#define XSTATE_BNDCSR 0x10
#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
+/* Bit 63 of XCR0 is reserved for future expansion */
+#define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1 63)))
This should be 1ULL, not 1. The compiler should have warned you.
Paolo
#define FXSAVE_SIZE512
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c697625..2d661e6 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -28,7 +28,7 @@ static u32 xstate_required_size(u64 xstate_bv)
int feature_bit = 0;
u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
- xstate_bv = ~XSTATE_FPSSE;
+ xstate_bv = XSTATE_EXTEND_MASK;
while (xstate_bv) {
if (xstate_bv 0x1) {
u32 eax, ebx, ecx, edx;
@@ -74,8 +74,8 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
vcpu-arch.guest_supported_xcr0 =
(best-eax | ((u64)best-edx 32))
host_xcr0 KVM_SUPPORTED_XCR0;
- vcpu-arch.guest_xstate_size =
- xstate_required_size(vcpu-arch.guest_supported_xcr0);
+ vcpu-arch.guest_xstate_size = best-ebx =
+ xstate_required_size(vcpu-arch.xcr0);
}
kvm_pmu_cpuid_update(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21ef1ba..1657ca2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -576,13 +576,13 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
- u64 xcr0;
+ u64 xcr0 = xcr;
+ u64 old_xcr0 = vcpu-arch.xcr0;
u64 valid_bits;
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
- xcr0 = xcr;
if (!(xcr0 XSTATE_FP))
return 1;
if ((xcr0 XSTATE_YMM) !(xcr0 XSTATE_SSE))
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
kvm_put_guest_xcr0(vcpu);
vcpu-arch.xcr0 = xcr0;
+
+ if ((xcr0 ^ old_xcr0) XSTATE_EXTEND_MASK)
+ kvm_update_cpuid(vcpu);
return 0;
}
--
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