Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752587AbdHXKNW (ORCPT ); Thu, 24 Aug 2017 06:13:22 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:34551 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751840AbdHXKND (ORCPT ); Thu, 24 Aug 2017 06:13:03 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: junkang.fjk@alibaba-inc.com, yang.zhang.wz@gmail.com, Yang Zhang Subject: [PATCH 3/3] KVM, pkeys: do not use PKRU value in vcpu->arch.guest_fpu.state Date: Thu, 24 Aug 2017 12:12:53 +0200 Message-Id: <1503569573-55057-4-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1503569573-55057-1-git-send-email-pbonzini@redhat.com> References: <1503569573-55057-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3107 Lines: 88 The host pkru is restored right after vcpu exit (commit 1be0e61), so KVM_GET_XSAVE will return the host PKRU value instead. Fix this by using the guest PKRU explicitly in fill_xsave and load_xsave. This part is based on a patch by Junkang Fu. The host PKRU data may also not match the value in vcpu->arch.guest_fpu.state, because it could have been changed by userspace since the last time it was saved, so skip loading it in kvm_load_guest_fpu. Reported-by: Junkang Fu Cc: Yang Zhang Fixes: 1be0e61c1f255faaeab04a390e00c8b9b9042870 Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/fpu/internal.h | 6 +++--- arch/x86/kvm/x86.c | 17 ++++++++++++++--- 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 255645f60ca2..554cdb205d17 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -450,10 +450,10 @@ static inline int copy_fpregs_to_fpstate(struct fpu *fpu) return 0; } -static inline void __copy_kernel_to_fpregs(union fpregs_state *fpstate) +static inline void __copy_kernel_to_fpregs(union fpregs_state *fpstate, u64 mask) { if (use_xsave()) { - copy_kernel_to_xregs(&fpstate->xsave, -1); + copy_kernel_to_xregs(&fpstate->xsave, mask); } else { if (use_fxsr()) copy_kernel_to_fxregs(&fpstate->fxsave); @@ -477,7 +477,7 @@ static inline void copy_kernel_to_fpregs(union fpregs_state *fpstate) : : [addr] "m" (fpstate)); } - __copy_kernel_to_fpregs(fpstate); + __copy_kernel_to_fpregs(fpstate, -1); } extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d734aa8c5b4f..05a5e57c6f39 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3245,7 +3245,12 @@ static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu) u32 size, offset, ecx, edx; cpuid_count(XSTATE_CPUID, index, &size, &offset, &ecx, &edx); - memcpy(dest + offset, src, size); + if (feature == XFEATURE_MASK_PKRU) + memcpy(dest + offset, &vcpu->arch.pkru, + sizeof(vcpu->arch.pkru)); + else + memcpy(dest + offset, src, size); + } valid -= feature; @@ -3283,7 +3288,11 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src) u32 size, offset, ecx, edx; cpuid_count(XSTATE_CPUID, index, &size, &offset, &ecx, &edx); - memcpy(dest, src + offset, size); + if (feature == XFEATURE_MASK_PKRU) + memcpy(&vcpu->arch.pkru, src + offset, + sizeof(vcpu->arch.pkru)); + else + memcpy(dest, src + offset, size); } valid -= feature; @@ -7633,7 +7642,9 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) */ vcpu->guest_fpu_loaded = 1; __kernel_fpu_begin(); - __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state); + /* PKRU is separately restored in kvm_x86_ops->run. */ + __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state, + ~XFEATURE_MASK_PKRU); trace_kvm_fpu(1); } -- 1.8.3.1