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[2620:137:e000::1:18]) by mx.google.com with ESMTPS id b24-20020a656698000000b00565dfc22f1bsi4029309pgw.865.2023.08.19.14.30.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Aug 2023 14:30:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=htfA+d+J; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 42754DDF9C; Sat, 19 Aug 2023 01:46:26 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238420AbjHOUiV (ORCPT + 99 others); Tue, 15 Aug 2023 16:38:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238408AbjHOUhs (ORCPT ); Tue, 15 Aug 2023 16:37:48 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 205271BFF for ; Tue, 15 Aug 2023 13:37:21 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-589ac93bc6eso76751067b3.0 for ; Tue, 15 Aug 2023 13:37:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692131826; x=1692736626; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=9kKru1xDygxSy2AxSK9xPxd/4keZZoge6XeY6EftrqI=; b=htfA+d+JXn13TTbcDzCya+D7HSIVA2axkaPqJBsVoewSSktqGFz525FTRsVq9P9NIo XssECs22HGRjHACcszmT4HDr0cCbMplg4AiK8vopMyWynPbngYBqFpLkOAZMwpXhMDbT 5qonhCEnd6RlLg+5/Al88Ly3w/i5eBToHJm6xVbMPKRmuwaaxqaAS6vMb1zVynSaQEEa ZPnRNc59ffRkfezUBzJ8pHTC3SpeFBdZBI7ZO/S54Sa3/Io48gPUIT2bcxHEsqgvUhgM 7RO9evsn9B2hiA4Bp2XmcgCbm7Lc0LkyvwEc73uEZuRD5ufrApC45FSOkKz9z1xkk021 IIJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692131826; x=1692736626; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=9kKru1xDygxSy2AxSK9xPxd/4keZZoge6XeY6EftrqI=; b=fBB809QHLFrZJ/3TYzxAXAc+yas99S24YMBsGjMSCKWYYpDBAeHXahoyZiZuy5ks+m jbKprmK4BPkmD5U3ETKcCR8SgpNqsypa2tmhXlnLFZlS4wQozhXI6yq5aWk1I3uB88GH Y2jQbfL9OzSyBakyYCapqssB0SCtfWPHAjlBr/6OR8i5vIfjsNQaQnZgwD1u0kVjoDJ5 PtpQ3QgSDg5IP/gkMW7ZqbMyYhQbe/I3KhV7OXr0CbOhJxCKVbz3O/SwCKNP75uNzL+R nyQRhQy8ntmUkQDpRWtLU/SmjAF59J/ysVAVTX1ncHJWmo7F9oOmq597Re6g2zrJaGhE DNKw== X-Gm-Message-State: AOJu0YzP9M3BDsm2kP6hkPVBuyXqjcM8i2hklhpVF7IDGQsIufTfG96h zuIxaVVAVFmqxDtt3GnVsqgd7c549JI= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a81:4420:0:b0:584:41a6:6cd8 with SMTP id r32-20020a814420000000b0058441a66cd8mr195692ywa.8.1692131826593; Tue, 15 Aug 2023 13:37:06 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 15 Aug 2023 13:36:44 -0700 In-Reply-To: <20230815203653.519297-1-seanjc@google.com> Mime-Version: 1.0 References: <20230815203653.519297-1-seanjc@google.com> X-Mailer: git-send-email 2.41.0.694.ge786442a9b-goog Message-ID: <20230815203653.519297-7-seanjc@google.com> Subject: [PATCH v3 06/15] KVM: x86: Use KVM-governed feature framework to track "XSAVES enabled" From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Zeng Guang , Yuan Yao X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1774694574555294629 X-GMAIL-MSGID: 1774694574555294629 Use the governed feature framework to track if XSAVES is "enabled", i.e. if XSAVES can be used by the guest. Add a comment in the SVM code to explain the very unintuitive logic of deliberately NOT checking if XSAVES is enumerated in the guest CPUID model. No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 1 - arch/x86/kvm/governed_features.h | 1 + arch/x86/kvm/svm/svm.c | 17 ++++++++++++--- arch/x86/kvm/vmx/vmx.c | 36 ++++++++++++++++---------------- arch/x86/kvm/x86.c | 4 ++-- 5 files changed, 35 insertions(+), 24 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 60d430b4650f..9f57aa33798b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -746,7 +746,6 @@ struct kvm_vcpu_arch { u64 smi_count; bool at_instruction_boundary; bool tpr_access_reporting; - bool xsaves_enabled; bool xfd_no_write_intercept; u64 ia32_xss; u64 microcode_version; diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h index b29c15d5e038..b896a64e4ac3 100644 --- a/arch/x86/kvm/governed_features.h +++ b/arch/x86/kvm/governed_features.h @@ -6,6 +6,7 @@ BUILD_BUG() #define KVM_GOVERNED_X86_FEATURE(x) KVM_GOVERNED_FEATURE(X86_FEATURE_##x) KVM_GOVERNED_X86_FEATURE(GBPAGES) +KVM_GOVERNED_X86_FEATURE(XSAVES) #undef KVM_GOVERNED_X86_FEATURE #undef KVM_GOVERNED_FEATURE diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 6aaa3c7b4578..d67f6e23dcd2 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4273,9 +4273,20 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) struct vcpu_svm *svm = to_svm(vcpu); struct kvm_cpuid_entry2 *best; - vcpu->arch.xsaves_enabled = guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && - boot_cpu_has(X86_FEATURE_XSAVE) && - boot_cpu_has(X86_FEATURE_XSAVES); + /* + * SVM doesn't provide a way to disable just XSAVES in the guest, KVM + * can only disable all variants of by disallowing CR4.OSXSAVE from + * being set. As a result, if the host has XSAVE and XSAVES, and the + * guest has XSAVE enabled, the guest can execute XSAVES without + * faulting. Treat XSAVES as enabled in this case regardless of + * whether it's advertised to the guest so that KVM context switches + * XSS on VM-Enter/VM-Exit. Failure to do so would effectively give + * the guest read/write access to the host's XSS. + */ + if (boot_cpu_has(X86_FEATURE_XSAVE) && + boot_cpu_has(X86_FEATURE_XSAVES) && + guest_cpuid_has(vcpu, X86_FEATURE_XSAVE)) + kvm_governed_feature_set(vcpu, X86_FEATURE_XSAVES); /* Update nrips enabled cache */ svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) && diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 22975cc949b7..6314ca32a5cf 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4543,16 +4543,19 @@ vmx_adjust_secondary_exec_control(struct vcpu_vmx *vmx, u32 *exec_control, * based on a single guest CPUID bit, with a dedicated feature bit. This also * verifies that the control is actually supported by KVM and hardware. */ -#define vmx_adjust_sec_exec_control(vmx, exec_control, name, feat_name, ctrl_name, exiting) \ -({ \ - bool __enabled; \ - \ - if (cpu_has_vmx_##name()) { \ - __enabled = guest_cpuid_has(&(vmx)->vcpu, \ - X86_FEATURE_##feat_name); \ - vmx_adjust_secondary_exec_control(vmx, exec_control, \ - SECONDARY_EXEC_##ctrl_name, __enabled, exiting); \ - } \ +#define vmx_adjust_sec_exec_control(vmx, exec_control, name, feat_name, ctrl_name, exiting) \ +({ \ + struct kvm_vcpu *__vcpu = &(vmx)->vcpu; \ + bool __enabled; \ + \ + if (cpu_has_vmx_##name()) { \ + if (kvm_is_governed_feature(X86_FEATURE_##feat_name)) \ + __enabled = guest_can_use(__vcpu, X86_FEATURE_##feat_name); \ + else \ + __enabled = guest_cpuid_has(__vcpu, X86_FEATURE_##feat_name); \ + vmx_adjust_secondary_exec_control(vmx, exec_control, SECONDARY_EXEC_##ctrl_name,\ + __enabled, exiting); \ + } \ }) /* More macro magic for ENABLE_/opt-in versus _EXITING/opt-out controls. */ @@ -4612,10 +4615,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) if (!enable_pml || !atomic_read(&vcpu->kvm->nr_memslots_dirty_logging)) exec_control &= ~SECONDARY_EXEC_ENABLE_PML; - if (cpu_has_vmx_xsaves()) - vmx_adjust_secondary_exec_control(vmx, &exec_control, - SECONDARY_EXEC_ENABLE_XSAVES, - vcpu->arch.xsaves_enabled, false); + vmx_adjust_sec_exec_feature(vmx, &exec_control, xsaves, XSAVES); /* * RDPID is also gated by ENABLE_RDTSCP, turn on the control if either @@ -4634,6 +4634,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) SECONDARY_EXEC_ENABLE_RDTSCP, rdpid_or_rdtscp_enabled, false); } + vmx_adjust_sec_exec_feature(vmx, &exec_control, invpcid, INVPCID); vmx_adjust_sec_exec_exiting(vmx, &exec_control, rdrand, RDRAND); @@ -7745,10 +7746,9 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) * to the guest. XSAVES depends on CR4.OSXSAVE, and CR4.OSXSAVE can be * set if and only if XSAVE is supported. */ - vcpu->arch.xsaves_enabled = kvm_cpu_cap_has(X86_FEATURE_XSAVES) && - boot_cpu_has(X86_FEATURE_XSAVE) && - guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && - guest_cpuid_has(vcpu, X86_FEATURE_XSAVES); + if (boot_cpu_has(X86_FEATURE_XSAVE) && + guest_cpuid_has(vcpu, X86_FEATURE_XSAVE)) + kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES); vmx_setup_uret_msrs(vmx); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eba35d43e3fe..34945c7dba38 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1016,7 +1016,7 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu) if (vcpu->arch.xcr0 != host_xcr0) xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0); - if (vcpu->arch.xsaves_enabled && + if (guest_can_use(vcpu, X86_FEATURE_XSAVES) && vcpu->arch.ia32_xss != host_xss) wrmsrl(MSR_IA32_XSS, vcpu->arch.ia32_xss); } @@ -1047,7 +1047,7 @@ void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu) if (vcpu->arch.xcr0 != host_xcr0) xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0); - if (vcpu->arch.xsaves_enabled && + if (guest_can_use(vcpu, X86_FEATURE_XSAVES) && vcpu->arch.ia32_xss != host_xss) wrmsrl(MSR_IA32_XSS, host_xss); } From patchwork Tue Aug 15 20:36:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 136095 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b82d:0:b0:3f2:4152:657d with SMTP id z13csp1938278vqi; Sat, 19 Aug 2023 03:03:34 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEJj9edU78NbNMQymgTvoat2DTWIepLSXcZFzC3FIw0Z3rR4g4u0QEy3p5qdNeuBO4lfBrr X-Received: by 2002:a05:6808:2028:b0:3a7:5557:16c2 with SMTP id q40-20020a056808202800b003a7555716c2mr3253397oiw.0.1692439414254; Sat, 19 Aug 2023 03:03:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1692439414; cv=none; d=google.com; s=arc-20160816; b=u7oXwOcv6ScWL6Cz45MELwuNalDMb0V0RIE+2LaaOL2yrPbwWNfLaLoWhpWkG1eX0U WfhSe74JVQZ66QdsnggiDj/ccvFeYv9UOG2a0kjq5TwNRSiyi84Sb3K1XU84eQ3JhCcl RqHK7UN/NnQu6/eYLUBKz5F+Rn0ljHz+mrLcPQwmHqg9Y3rBHP95aDwNAqip2tlTn9lO 3py74/oNrMSHYgNe3uIiU+fWsp5ZogkmRBgxC8EycyClqlMZwfrPidSNCegeow4OVYhr RLlJtDstbycOnXJ6FQmfOwAW6qalbaSEBf2EGGpT6IM/ZX+eAY3pqULX/VDZDTAveJMc hQ/Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:reply-to:dkim-signature; bh=/gyHxemWXBUuNtn9G6ZmWdv+kLBQgF3gAw0dAQJK39U=; fh=Ene4UBUMXV+HKo0HGGPHdENtOqH6ZZIqSck1iNZF77Q=; b=BlXP90ABB/qzmjLqmbR0YgfhEqnrOUlxVSxOoX8UiJ4fR+nffnIxpJ5wf8iW/ecvk8 qhmdRjafqaK7xgirWvqSVcyPZWxETIDtWqgzdIKk3k8Xxay3XO2onH4MnCU+pZPce4d7 Bt60nCrkP5qtFOdpkMvFUTpmMbi8g1re/rWU0FAM7fDrCQHsqvAZcCGxpRRdXPdX+hPe ryc2SB8xHugrGcPuIeZkW/knQPtPY1ZXhzZT16vVTXcs6QNqXNZ0MulsaITIig1gt/xz iecNlycDiOs9vJXPfzkEYyrieyOkjKMnUkg809vJ623HVbysVORaBLLjKhumPx/QKdM5 8qsw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=QjV9eR7W; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net. [2620:137:e000::1:18]) by mx.google.com with ESMTPS id h71-20020a63834a000000b0055baf9fc388si3161501pge.860.2023.08.19.03.03.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Aug 2023 03:03:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=QjV9eR7W; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8E6D63A883; Sat, 19 Aug 2023 01:29:43 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238907AbjHOUi3 (ORCPT + 99 others); Tue, 15 Aug 2023 16:38:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238950AbjHOUh7 (ORCPT ); Tue, 15 Aug 2023 16:37:59 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E8F11FF9 for ; Tue, 15 Aug 2023 13:37:35 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-589fae40913so28344697b3.0 for ; Tue, 15 Aug 2023 13:37:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692131832; x=1692736632; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=/gyHxemWXBUuNtn9G6ZmWdv+kLBQgF3gAw0dAQJK39U=; b=QjV9eR7WVBYauzi+3qEmMZRbGnogEfU+B0zFQOnCsCmKlA5Y7+WABAvNAKoUACRX2L FJ7bX6MfATSvoHUMEjiRdyOyWdK7TAlddykPKqbCqchQezNPP6N6uWjI6TcTnnONoQOo Y7zIs8TyBi4tOanPhjiQgenTT3IGnkss334NihSIzpzM+0JLpXHYP+bxavbA3mzM5b4e cQ5Tm47QyV+q1KcQgqcNOl3dUPAgOeWXukEWRpmrEqdobuhlJXP8E+uEKa/EOYHQPTBY ltSICRi8gyLsbi/nOUR5RjYVMs8l1CUTjh/OVD9xL22H1feIKA+awmeD6atr/MdsHmTo 2iGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692131832; x=1692736632; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=/gyHxemWXBUuNtn9G6ZmWdv+kLBQgF3gAw0dAQJK39U=; b=AdvxGUSgb0y+Oq3xxFvro+Tv5YuQ6JUdgl3fM1r/hiIngF//xSqwM29jyX81Plg5nw Bk4Lic50SN6eAdFKrG3oeZeP7Vv7+WZ/Hg4+b8dX8UwcGOqRmXdqMcfeZ4SbLX/t5KBw 7iiIN2qYHkIT7bwC8VqcFa9PUtwK9m+wy3FoxKPOPM22/4HJlpLYqg/K/411vlKcoNhc zLZdQ7HbP8aMQCMELwSp32DdkJnGLA1Vbicf0hJeHL/mw8xxMjqx5z6wtYfiwKeayVco jHAL0acteFeWFMXSsQwKlUjqiK43avsxp7qt5JhhcsLt75mwX7HyLjQp7lcAqQiQEAje /0xA== X-Gm-Message-State: AOJu0YzvToCafLrSiWH8wu6x39j4mj5I6pWpPDGZG1fWEUrMNdSe74v+ H62DeNKTDzp/FNnh5OA+m6GMlQOs7fk= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:4c7:b0:d5d:511b:16da with SMTP id v7-20020a05690204c700b00d5d511b16damr180847ybs.2.1692131832254; Tue, 15 Aug 2023 13:37:12 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 15 Aug 2023 13:36:47 -0700 In-Reply-To: <20230815203653.519297-1-seanjc@google.com> Mime-Version: 1.0 References: <20230815203653.519297-1-seanjc@google.com> X-Mailer: git-send-email 2.41.0.694.ge786442a9b-goog Message-ID: <20230815203653.519297-10-seanjc@google.com> Subject: [PATCH v3 09/15] KVM: nSVM: Use KVM-governed feature framework to track "TSC scaling enabled" From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Zeng Guang , Yuan Yao X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1774651350954979515 X-GMAIL-MSGID: 1774651350954979515 Track "TSC scaling exposed to L1" via a governed feature flag instead of using a dedicated bit/flag in vcpu_svm. Note, this fixes a benign bug where KVM would mark TSC scaling as exposed to L1 even if overall nested SVM supported is disabled, i.e. KVM would let L1 write MSR_AMD64_TSC_RATIO even when KVM didn't advertise TSCRATEMSR support to userspace. Signed-off-by: Sean Christopherson --- arch/x86/kvm/governed_features.h | 1 + arch/x86/kvm/svm/nested.c | 2 +- arch/x86/kvm/svm/svm.c | 10 ++++++---- arch/x86/kvm/svm/svm.h | 1 - 4 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h index 722b66af412c..32c0469cf952 100644 --- a/arch/x86/kvm/governed_features.h +++ b/arch/x86/kvm/governed_features.h @@ -9,6 +9,7 @@ KVM_GOVERNED_X86_FEATURE(GBPAGES) KVM_GOVERNED_X86_FEATURE(XSAVES) KVM_GOVERNED_X86_FEATURE(VMX) KVM_GOVERNED_X86_FEATURE(NRIPS) +KVM_GOVERNED_X86_FEATURE(TSCRATEMSR) #undef KVM_GOVERNED_X86_FEATURE #undef KVM_GOVERNED_FEATURE diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 9092f3f8dccf..da65948064dc 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -695,7 +695,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm, vmcb02->control.tsc_offset = vcpu->arch.tsc_offset; - if (svm->tsc_scaling_enabled && + if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) && svm->tsc_ratio_msr != kvm_caps.default_tsc_scaling_ratio) nested_svm_update_tsc_ratio_msr(vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index c8b97cb3138c..15c79457d8c5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2809,7 +2809,8 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) switch (msr_info->index) { case MSR_AMD64_TSC_RATIO: - if (!msr_info->host_initiated && !svm->tsc_scaling_enabled) + if (!msr_info->host_initiated && + !guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR)) return 1; msr_info->data = svm->tsc_ratio_msr; break; @@ -2959,7 +2960,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) switch (ecx) { case MSR_AMD64_TSC_RATIO: - if (!svm->tsc_scaling_enabled) { + if (!guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR)) { if (!msr->host_initiated) return 1; @@ -2981,7 +2982,8 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) svm->tsc_ratio_msr = data; - if (svm->tsc_scaling_enabled && is_guest_mode(vcpu)) + if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) && + is_guest_mode(vcpu)) nested_svm_update_tsc_ratio_msr(vcpu); break; @@ -4289,8 +4291,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) kvm_governed_feature_set(vcpu, X86_FEATURE_XSAVES); kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_NRIPS); + kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_TSCRATEMSR); - svm->tsc_scaling_enabled = tsc_scaling && guest_cpuid_has(vcpu, X86_FEATURE_TSCRATEMSR); svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV); svm->v_vmload_vmsave_enabled = vls && guest_cpuid_has(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index e147f2046ffa..3696f10e2887 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -259,7 +259,6 @@ struct vcpu_svm { bool soft_int_injected; /* optional nested SVM features that are enabled for this guest */ - bool tsc_scaling_enabled : 1; bool v_vmload_vmsave_enabled : 1; bool lbrv_enabled : 1; bool pause_filter_enabled : 1;