From patchwork Fri Jan 22 20:40:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12040433 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, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 0BF4FC433E0 for ; Fri, 22 Jan 2021 20:43:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D268123B06 for ; Fri, 22 Jan 2021 20:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730487AbhAVUm6 (ORCPT ); Fri, 22 Jan 2021 15:42:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730519AbhAVUl5 (ORCPT ); Fri, 22 Jan 2021 15:41:57 -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 4AD7CC061794 for ; Fri, 22 Jan 2021 12:41:01 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id l3so6652248ybl.17 for ; Fri, 22 Jan 2021 12:41:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=pyxHmRO3h+haE3GvdjoFL8/WjTXx2t0JBZMhtHNwcy4=; b=qULn3gC2JI23ZACklCrVFPH5xhV9FcCh5pr32mrm7ML5uUbqEquuC47toqsDtYjeYz /vWQ7/hpxBOldcPTDbwAOysm5k7C/HcrThH5CFikVD0ZDsDbsq6DrneZvkEIY+nbuWwH PMBofzdU/eJGwFsp28amnxA6U1Ki0wfxxKcGk3ToFr60xtShikL6mjIN2qXxB0Q4MPKA Vy9GzIx5T9GEsSgq9QpF2ukGJN36n5tZMQxICuYaT1/fGJWHlkjqQWzpPPsgy2dUoSgW vlnyHmEvceznYufijHCik3v+ir/gEFHJJ0hLfVN0U4tIWihWaT5yrihgYH3qhEhBSX9I wApg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=pyxHmRO3h+haE3GvdjoFL8/WjTXx2t0JBZMhtHNwcy4=; b=g6XpxNBQnr/xNXRZ17B8Z0ZYv6xN7ZRJ9Vz8x9mM5L0hXAk5Kdd+sxqQejGsHXtJvp vn9ppG6RUx8t5XYhX1O64Fx9qz9geM6RdilQ5rynka9BH+Bldb4b1pjYw90G7Lud82D0 pYAZ9E4OprThPREG9jQeNtmXKpvH1qP9PZkoqbB3Xbcq5z+bzH0++p/pNq/J84PtJGVA erk9cb6zoySQZp6oO15Mc/HCnLovXVMxwS8rm/yUSPT0vABTQLgB+p+aqoWmQfJ1YOBe jZ0AprlIP+VW77oFtXFC/CEoTigamaQgDKE/CSwn2Udo017X6db7zxTbMyG5q58WGZU0 +8IQ== X-Gm-Message-State: AOAM531BHvLXmzKZYj0BPimUM0NJPuDtt7L8f1dWTGzkcgpj0hOemGjw tnc3W6UVYauGGPeZJR7wWDidGoQEpss= X-Google-Smtp-Source: ABdhPJwpymYTKSo4i45gzHRjk4zVwg3jh4A09yJceemynb6NjecSeQmF/7Bpp7hRXWbfzC49vBZWry7fx00= Sender: "seanjc via sendgmr" X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) (user=seanjc job=sendgmr) by 2002:a05:6902:706:: with SMTP id k6mr9162371ybt.52.1611348060485; Fri, 22 Jan 2021 12:41:00 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 22 Jan 2021 12:40:47 -0800 In-Reply-To: <20210122204047.2860075-1-seanjc@google.com> Message-Id: <20210122204047.2860075-3-seanjc@google.com> Mime-Version: 1.0 References: <20210122204047.2860075-1-seanjc@google.com> X-Mailer: git-send-email 2.30.0.280.ga3ce27912f-goog Subject: [PATCH v3 2/2] KVM: x86: Override reported SME/SEV feature flags with host mask From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, Paolo Bonzini Cc: "H. Peter Anvin" , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Brijesh Singh , Tom Lendacky Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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. Cc: Tom Lendacky Reviewed-by: Brijesh Singh Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 2 ++ arch/x86/kvm/cpuid.h | 1 + 2 files changed, 3 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 13036cf0b912..b7618cdd06b5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -855,6 +855,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) case 0x8000001F: if (!boot_cpu_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 dc921d76e42e..8b6fc9bde248 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -63,6 +63,7 @@ static const struct cpuid_reg reverse_cpuid[] = { [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX}, [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, + [CPUID_8000_001F_EAX] = {0x8000001f, 1, CPUID_EAX}, }; /*