>From 44c2abca2c2eadc6f2f752b66de4acc8131880c4 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <[email protected]>
Date: Mon, 24 Feb 2014 18:12:31 +0800
Subject: [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest
This patch enable Intel MPX feature to guest.
Signed-off-by: Xudong Hao <[email protected]>
Signed-off-by: Liu Jinsong <[email protected]>
---
arch/x86/kvm/cpuid.c | 4 +++-
arch/x86/kvm/x86.c | 6 ++++++
arch/x86/kvm/x86.h | 3 ++-
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b241325..ddc8a7e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -256,6 +256,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
#endif
unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
+ unsigned f_mpx = kvm_x86_ops->mpx_supported ?
+ (kvm_x86_ops->mpx_supported() ? F(MPX) : 0) : 0;
/* cpuid 1.edx */
const u32 kvm_supported_word0_x86_features =
@@ -303,7 +305,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 7.0.ebx */
const u32 kvm_supported_word9_x86_features =
F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
- F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | F(RDSEED) |
+ F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
F(ADX);
/* all calls to cpuid_count() should be made on the same cpu */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 89e4e27..3570e71 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
u64 old_xcr0 = vcpu->arch.xcr0;
u64 valid_bits;
+ if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported())
+ xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
+
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
@@ -616,6 +619,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
if (xcr0 & ~valid_bits)
return 1;
+ if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR)))
+ return 1;
+
kvm_put_guest_xcr0(vcpu);
vcpu->arch.xcr0 = xcr0;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 8da5823..392ecbf 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -122,7 +122,8 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val, unsigned int bytes,
struct x86_exception *exception);
-#define KVM_SUPPORTED_XCR0 (XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
+#define KVM_SUPPORTED_XCR0 (XSTATE_FP | XSTATE_SSE | XSTATE_YMM \
+ | XSTATE_BNDREGS | XSTATE_BNDCSR)
extern u64 host_xcr0;
extern unsigned int min_timer_period_us;
--
1.7.1
Il 24/02/2014 11:58, Liu, Jinsong ha scritto:
> @@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
> u64 old_xcr0 = vcpu->arch.xcr0;
> u64 valid_bits;
>
> + if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported())
> + xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
> +
> /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
> if (index != XCR_XFEATURE_ENABLED_MASK)
> return 1;
This hunk is incorrect, and I can simply drop it when applying. If MPX
is not supported, it should not be in the 0Dh CPUID leaf and thus in
vcpu->arch.guest_supported_xcr0.
This however relies on userspace passing a "sensible" value of CPUID.
I'll send a patch to strengthen the computation of guest_supported_xcr0.
Thanks!
Paolo
Paolo Bonzini wrote:
> Il 24/02/2014 11:58, Liu, Jinsong ha scritto:
>> @@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32
>> index, u64 xcr) u64 old_xcr0 = vcpu->arch.xcr0;
>> u64 valid_bits;
>>
>> + if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported())
>> + xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
>> +
>> /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
>> if (index != XCR_XFEATURE_ENABLED_MASK)
>> return 1;
>
> This hunk is incorrect, and I can simply drop it when applying. If
> MPX is not supported, it should not be in the 0Dh CPUID leaf and thus
> in vcpu->arch.guest_supported_xcr0.
>
> This however relies on userspace passing a "sensible" value of CPUID.
> I'll send a patch to strengthen the computation of
> guest_supported_xcr0.
>
> Thanks!
>
> Paolo
So patch v5 would be applied except you will remove the incorrect hunk, and you will send a patch strengthenning guest_supported_xcr0?
Thanks,
Jinsong-
Il 24/02/2014 16:37, Liu, Jinsong ha scritto:
> So patch v5 would be applied except you will remove the incorrect
> hunk, and you will send a patch strengthenning guest_supported_xcr0?
Yes.
Paolo