diff options
| author | Liu, Jinsong <jinsong.liu@intel.com> | 2014-02-21 17:39:02 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-02-22 15:53:34 +0100 |
| commit | 56c103ec040b1944c8866f79aa768265c0dd2986 (patch) | |
| tree | 7201960f61ecfd19f3e78dfa6d6526822f055786 /arch | |
| parent | 49345f13f0830741b94b867cf906c4aad3988306 (diff) | |
KVM: x86: Fix xsave cpuid exposing bug
From 00c920c96127d20d4c3bb790082700ae375c39a0 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Fri, 21 Feb 2014 23:47:18 +0800
Subject: [PATCH] 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.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/xsave.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 6 | ||||
| -rw-r--r-- | 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 554738963b28..dcd047b629ec 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 | (1ULL << 63))) #define FXSAVE_SIZE 512 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index a951ae4d2370..b241325b5965 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 151e8c3b1f4a..3da8df8ea63c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -595,13 +595,13 @@ 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)) @@ -618,6 +618,9 @@ 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; } |