Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755526AbeAIMDi (ORCPT + 1 other); Tue, 9 Jan 2018 07:03:38 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:37075 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754097AbeAIMDc (ORCPT ); Tue, 9 Jan 2018 07:03:32 -0500 X-Google-Smtp-Source: ACJfBotBtUm0Knz5+XmfAYSCM7v/3RddKQQwJskwXHGfvlHQFB40AdsWsDwYN4KyWAP+07Z7pUvhTw== From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: rkrcmar@redhat.com, liran.alon@oracle.com, jmattson@google.com, aliguori@amazon.com, thomas.lendacky@amd.com, dwmw@amazon.co.uk, bp@alien8.de, x86@kernel.org Subject: [PATCH 9/8] KVM: x86: limit MSR_IA32_SPEC_CTRL access based on CPUID availability Date: Tue, 9 Jan 2018 13:03:11 +0100 Message-Id: <20180109120311.27565-10-pbonzini@redhat.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180109120311.27565-1-pbonzini@redhat.com> References: <20180109120311.27565-1-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: MSR_IA32_SPEC_CTRL is not available unless CPU[7,0].EDX[26] is 1. Check that against host CPUID or guest CPUID, respectively for host-initiated and guest-initiated accesses. Suggested-by: Jim Mattson Signed-off-by: Paolo Bonzini --- This is for after X86_FEATURE_SPEC_CTRL is added to Linux, but I still wanted to ack Jim's improvement. arch/x86/kvm/svm.c | 8 ++++++++ arch/x86/kvm/vmx.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 97126c2bd663..3a646580d7c5 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3648,6 +3648,10 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = svm->nested.vm_cr_msr; break; case MSR_IA32_SPEC_CTRL: + if (!static_cpu_has(X86_FEATURE_SPEC_CTRL) || + (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))) + return 1; msr_info->data = svm->spec_ctrl; break; case MSR_IA32_UCODE_REV: @@ -3806,6 +3810,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data); break; case MSR_IA32_SPEC_CTRL: + if (!static_cpu_has(X86_FEATURE_SPEC_CTRL) || + (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))) + return 1; svm->spec_ctrl = data; break; case MSR_IA32_APICBASE: diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 49b4a2d61603..42bc7ee293e4 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3368,6 +3368,10 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = guest_read_tsc(vcpu); break; case MSR_IA32_SPEC_CTRL: + if (!static_cpu_has(X86_FEATURE_SPEC_CTRL) || + (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))) + return 1; msr_info->data = to_vmx(vcpu)->spec_ctrl; break; case MSR_IA32_SYSENTER_CS: @@ -3510,6 +3514,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) kvm_write_tsc(vcpu, msr_info); break; case MSR_IA32_SPEC_CTRL: + if (!static_cpu_has(X86_FEATURE_SPEC_CTRL) || + (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))) + return 1; to_vmx(vcpu)->spec_ctrl = data; break; case MSR_IA32_CR_PAT: -- 1.8.3.1