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[2620:137:e000::1:20]) by mx.google.com with ESMTP id u16-20020aa7d990000000b004acc6cbcca1si6365909eds.342.2023.02.17.15.11.45; Fri, 17 Feb 2023 15:12:09 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=evWLFJz9; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbjBQXKz (ORCPT + 99 others); Fri, 17 Feb 2023 18:10:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229914AbjBQXKm (ORCPT ); Fri, 17 Feb 2023 18:10:42 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E10768AC9 for ; Fri, 17 Feb 2023 15:10:36 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id 188-20020a2503c5000000b008e1de4c1e7dso2131606ybd.17 for ; Fri, 17 Feb 2023 15:10:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; 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=2TnnXLHs2EigAQxoZxOgm8ELOh1fY6tAR5v57woQrQM=; b=evWLFJz9F/oKh/+eqv6kDQcb25TLjrSKGiZ+885GucdcbYldsNDzdH5NDukODm5mES Xax2e9thCVVomFzY5yxPyLPBjJkAtXUsgxyTUk3DlpsaylUfFdp6qu59Md5UtCpFeWHT riYbvV5qIXDbPm0yBIP//Xxf/o/cfrnOxu+wv8G5R4Z4ibzLL1o1LLzJ+FveFN19oNVT vTCEusG7Vs/2GMEH2O0V6eV+mmI3qKAezzH4K5cFM922iXnY1DSBwSdRnNp57rGpFtdp MM5BMjHWDkRSFwYXcQVxjyFPFKgTon0rJNdIbPuXnBizF+upt3SEQVw+Om1aDVl9JwKr l6Gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=2TnnXLHs2EigAQxoZxOgm8ELOh1fY6tAR5v57woQrQM=; b=0jPE/ypOU80lcUsuhxtqjMrknJTkcwdu02PCVlYrZEJglG6PDpAyyM+ODIeGXLnaCy z2X6MEVMPIf0BB6rbOqnkbKUqizgdTcl7YKIqHPUkc1+VkHFu7pWD3NLl5yGQGC4u5D1 R6HSaGuWzEiFPRQKaiLbyN6gwJkvXmi60LHUeq1sx03rEPEbVAG3yOKKjQzsGJqFtruN Rqy9HSSfU3Yv7rLZfCnuKd2jae3ILi7gxDgtMu2a8SfK6B9stuY7fPiprlJ2n1GXDlxb imvWOeLPHTj6qxmc2LHl81OI6vv5DsLumk/b2hmfxxwLOjHRGwwTsueD42gFmA3d9tIu l5WQ== X-Gm-Message-State: AO0yUKXRo8o5+E9VyEd+UdLT+ns9LI76ucjr2Bz/52YaJN2ODGb9Qqlr NWzNtPrYySLEqH3wB1Vp+iygRLRMs58= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a0d:d543:0:b0:52e:ebb7:98f9 with SMTP id x64-20020a0dd543000000b0052eebb798f9mr1162884ywd.201.1676675435569; Fri, 17 Feb 2023 15:10:35 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 17 Feb 2023 15:10:15 -0800 In-Reply-To: <20230217231022.816138-1-seanjc@google.com> Mime-Version: 1.0 References: <20230217231022.816138-1-seanjc@google.com> X-Mailer: git-send-email 2.39.2.637.g21b0678d19-goog Message-ID: <20230217231022.816138-6-seanjc@google.com> Subject: [PATCH 05/12] 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 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_NONE, 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: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1758121719510538095?= X-GMAIL-MSGID: =?utf-8?q?1758121719510538095?= 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/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 ++-- 4 files changed, 35 insertions(+), 23 deletions(-) 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 b43775490074..d89e516449ad 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4128,9 +4128,20 @@ 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 14ce195eee5a..c64a12756016 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4551,16 +4551,19 @@ 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. */ @@ -4620,10 +4623,7 @@ 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 @@ -4642,6 +4642,7 @@ 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); @@ -7705,10 +7706,9 @@ 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 = cpu_has_vmx_xsaves() && - boot_cpu_has(X86_FEATURE_XSAVE) && - guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && - guest_cpuid_has(vcpu, X86_FEATURE_XSAVES); + if (cpu_has_vmx_xsaves() && 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 f706621c35b8..541982de5762 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -988,7 +988,7 @@ 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); } @@ -1023,7 +1023,7 @@ 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); }