Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbaBVOzk (ORCPT ); Sat, 22 Feb 2014 09:55:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:6739 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751868AbaBVOzX (ORCPT ); Sat, 22 Feb 2014 09:55:23 -0500 Message-ID: <5308BA54.2040807@redhat.com> Date: Sat, 22 Feb 2014 15:55:16 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Liu, Jinsong" CC: "gleb@redhat.com" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "qemu-devel@nongnu.org" Subject: Re: [PATCH] KVM: x86: Fix xsave cpuid exposing bug References: In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 21/02/2014 18:39, Liu, Jinsong ha scritto: > From 00c920c96127d20d4c3bb790082700ae375c39a0 Mon Sep 17 00:00:00 2001 > From: Liu Jinsong > 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 > --- > 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..dcd047b 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 a951ae4..b241325 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 39c28f0..7c52acb 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; > } > > Applied to kvm/queue, thanks. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/