From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D19E4C433B4 for ; Thu, 22 Apr 2021 02:11:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5C3B613A9 for ; Thu, 22 Apr 2021 02:11:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234584AbhDVCM2 (ORCPT ); Wed, 21 Apr 2021 22:12:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234272AbhDVCMP (ORCPT ); Wed, 21 Apr 2021 22:12:15 -0400 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 2F35EC06174A for ; Wed, 21 Apr 2021 19:11:40 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id u73-20020a25ab4f0000b0290410f38a2f81so18069613ybi.22 for ; Wed, 21 Apr 2021 19:11:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=GoSZGv7Y6e7lARdhV5mketnMC+wBjLMFqgO+1KaTReY=; b=GMw18gHVAzCwv+LaoeobpVSexFsDlMyhVgVQj7ByXdguQRXy3VfPbpxTxY8z17nuUl kriJI+OtRmL8/11pJ2E7dPQtOk7xO3jcOiVWNUqXk2FxD2vHkdgyYXdHSbm3lr7hBbLd puuF7YjDhGs3eWtlVyqU45r3WL1mx+xoOC3ivJWHAJNVyH2pHv01q7wgCfmJWz1jqDl1 CQXeiv5I+QIgp+PCTBL2nzo8sLbzKgYQAiGJtncQf7aTIH7NNmSReS5NLXRHHmWj8bcc ryElqUKI2uTWlpiEEbWU+CXnI73fXmX7wponLwq1vQIC4pcYieRCulfr81fjzbNDZc9v guQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=GoSZGv7Y6e7lARdhV5mketnMC+wBjLMFqgO+1KaTReY=; b=hheqjPYhYK7uDHH1ZpTzOf8EIq5QOrJopw/J/tILXGemciMRSVxGfpHJlmoVczXk9s prDtGveUFoLVsitRwBg4dvKDh/rDbKQXrbTdPHgvByMaMBP7M7IkF8iemZjRtT14xAub o/60rC7ouKresGmlJNVUZdXd7AxG5OXnTrEv68jLd4t4hayM/6hbKOu1VqeBRMFmlyFU q1jBvzMZAcGlsGHpCra5h2MTOBdFDhG1gy/G5X0L5++wGfZJlmAB/gu9eEVBFyJDQ5p0 BvjWfNCE5gu2TX+h4HtqC/S1LSazKmXRX7el6iT1Hx0ol3PPVo3jSOy7wP7fCXN61IEk Avzw== X-Gm-Message-State: AOAM530CXQCSNh/QCzMXpxVvvzyfzbl6rRsJGWojBhh7gtfLAaILrHWy D5f7wNsPQebcr/4UQBe1EvIGhxK9gz4= X-Google-Smtp-Source: ABdhPJxvg9wZgV5GpAgYuTY1uGCh0VjFAGn0+XLUAiUby4Errpq5ObcHR2latnfc4kXAu5iX/bb354pUBeA= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:e012:374c:592:6194]) (user=seanjc job=sendgmr) by 2002:a25:ef0c:: with SMTP id g12mr1292284ybd.235.1619057499451; Wed, 21 Apr 2021 19:11:39 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 21 Apr 2021 19:11:15 -0700 In-Reply-To: <20210422021125.3417167-1-seanjc@google.com> Message-Id: <20210422021125.3417167-6-seanjc@google.com> Mime-Version: 1.0 References: <20210422021125.3417167-1-seanjc@google.com> X-Mailer: git-send-email 2.31.1.498.g6c1eba8ee3d-goog Subject: [PATCH v5 05/15] KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features From: Sean Christopherson To: Paolo Bonzini , Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Tom Lendacky , Brijesh Singh Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paolo Bonzini Add a reverse-CPUID entry for the memory encryption word, 0x8000001F.EAX, and use it to override the supported CPUID flags reported to userspace. Masking the reported CPUID flags avoids over-reporting KVM support, e.g. without the mask a SEV-SNP capable CPU may incorrectly advertise SNP support to userspace. Clear SEV/SEV-ES if their corresponding module parameters are disabled, and clear the memory encryption leaf completely if SEV is not fully supported in KVM. Advertise SME_COHERENT in addition to SEV and SEV-ES, as the guest can use SME_COHERENT to avoid CLFLUSH operations. Explicitly omit SME and VM_PAGE_FLUSH from the reporting. These features are used by KVM, but are not exposed to the guest, e.g. guest access to related MSRs will fault. Cc: Tom Lendacky Cc: Brijesh Singh Signed-off-by: Paolo Bonzini Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 8 +++++++- arch/x86/kvm/cpuid.h | 1 + arch/x86/kvm/svm/sev.c | 8 ++++++++ arch/x86/kvm/svm/svm.c | 3 +++ arch/x86/kvm/svm/svm.h | 1 + 5 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 2ae061586677..96e41e1a1bde 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -557,6 +557,10 @@ void kvm_set_cpu_caps(void) */ kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0); + kvm_cpu_cap_mask(CPUID_8000_001F_EAX, + 0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) | + F(SME_COHERENT)); + kvm_cpu_cap_mask(CPUID_C000_0001_EDX, F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | @@ -944,8 +948,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) break; /* Support memory encryption cpuid if host supports it */ case 0x8000001F: - if (!boot_cpu_has(X86_FEATURE_SEV)) + if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) entry->eax = entry->ebx = entry->ecx = entry->edx = 0; + else + cpuid_entry_override(entry, CPUID_8000_001F_EAX); break; /*Add support for Centaur's CPUID instruction*/ case 0xC0000000: diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 888e88b42e8d..eeb4a3020e1b 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -99,6 +99,7 @@ static const struct cpuid_reg reverse_cpuid[] = { [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, [CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX}, + [CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX}, }; /* diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index fb32b93e325c..e54eff6dfbbe 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1764,6 +1764,14 @@ void sev_vm_destroy(struct kvm *kvm) sev_asid_free(sev->asid); } +void __init sev_set_cpu_caps(void) +{ + if (!sev) + kvm_cpu_cap_clear(X86_FEATURE_SEV); + if (!sev_es) + kvm_cpu_cap_clear(X86_FEATURE_SEV_ES); +} + void __init sev_hardware_setup(void) { unsigned int eax, ebx, ecx, edx; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 12b2c04076bb..cb227e90dffb 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -914,6 +914,9 @@ static __init void svm_set_cpu_caps(void) if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) || boot_cpu_has(X86_FEATURE_AMD_SSBD)) kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); + + /* CPUID 0x8000001F (SME/SEV features) */ + sev_set_cpu_caps(); } static __init int svm_hardware_setup(void) diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index ec0407f41458..39d1412f2c45 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -581,6 +581,7 @@ int svm_unregister_enc_region(struct kvm *kvm, struct kvm_enc_region *range); int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd); void pre_sev_run(struct vcpu_svm *svm, int cpu); +void __init sev_set_cpu_caps(void); void __init sev_hardware_setup(void); void sev_hardware_teardown(void); void sev_free_vcpu(struct kvm_vcpu *vcpu); -- 2.31.1.498.g6c1eba8ee3d-goog