From nobody Tue Feb 10 06:04:55 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1737BC77B7C for ; Fri, 12 May 2023 23:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241646AbjELXw1 (ORCPT ); Fri, 12 May 2023 19:52:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241055AbjELXvu (ORCPT ); Fri, 12 May 2023 19:51:50 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10BE0DDB4 for ; Fri, 12 May 2023 16:51:09 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id 98e67ed59e1d1-24e3e52228cso5750091a91.1 for ; Fri, 12 May 2023 16:51:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683935455; x=1686527455; 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=GHUYV32ME1G34t9dLxIdgC9KAsI3wgHSef3OtvHGUi0=; b=uhvP9GADu6S2ysvZ4kh5xkuiPjuKVJRMq0PLpWZGHB4wN8ed+iVJWoHLk2ep7fROUS IJycgzlSDI8KEjSYA7mhEkmYSTSRapx9HtpLQpyiXnYjv4PIH3g1bQjbPE3jFf8lpkt5 Gz78mLJDvk26m0aoygfQSTni1RV6EEk702oXX0lbtARIPa5i+nG1qe/9p8WYi7EXQ4ci sWm00cWad9ylKiwTdJF0lEvU75K1r2JFScJziAkNIJO6xRwg3MMPi7Tas8rH0Q4N5lv+ D3uIq9/OHxMY191f2bHbcVrxhuqdvgJLL6xlE8p5uPUNNs0RStLkt4Bg59filrO+q2W+ Hz3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683935455; x=1686527455; 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=GHUYV32ME1G34t9dLxIdgC9KAsI3wgHSef3OtvHGUi0=; b=OnG8QQuLLC82zQBy5nT6MKQWuaC2lqKsdPha0bZDmnNG0Nmgg8tgY/tQ7mtWLHv4Xa MhxzHCc7n82DXPkH4b41xDlgXixNE3NaLDPHSNTts1dQgSfdfgNO+5z08e4hfFD7QA+k i+aGEy5JL4dZjicOhraMEh94c3JDMHJ6hcPfAlvk5V3ZJiQk0ahqw8bWF6rN8e391c2S JI6WbFMhrzpOAE6HUb0kP1cQllHm2vgJPahfQlxoA7qOCKDS3WDT4NQc3g2x+D7MceTO zvzJN83uRlphFt9x5wA8/x2Mx11MrFNM4EDHmceN/BUVMstJcXBfb2awZdphgBm0G1m6 9ZoA== X-Gm-Message-State: AC+VfDy4oxXZuLMRDE5mPEsNP7QkZX+R9YaAHUOSPAfzIzyysYckvDoG nX7qOyE0EggzU4IXOCHqZVVTzU9Kx6U= X-Google-Smtp-Source: ACHHUZ5Q/Sy2dSoFMDVllQliE/fb5qz6zq0oSCa0U5wcU+tF+6w0q8dnUNsC+gKScE1N5jOd94K19SP9wn8= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90b:8d1:b0:252:7118:4711 with SMTP id ds17-20020a17090b08d100b0025271184711mr2723466pjb.5.1683935455774; Fri, 12 May 2023 16:50:55 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 12 May 2023 16:50:22 -0700 In-Reply-To: <20230512235026.808058-1-seanjc@google.com> Mime-Version: 1.0 References: <20230512235026.808058-1-seanjc@google.com> X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog Message-ID: <20230512235026.808058-15-seanjc@google.com> Subject: [PATCH v3 14/18] KVM: SVM: Check that the current CPU supports SVM in kvm_is_svm_supported() From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Cooper , Kai Huang , Chao Gao Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Check "this" CPU instead of the boot CPU when querying SVM support so that the per-CPU checks done during hardware enabling actually function as intended, i.e. will detect issues where SVM isn't support on all CPUs. Disable migration for the use from svm_init() mostly so that the standard accessors for the per-CPU data can be used without getting yelled at by CONFIG_DEBUG_PREEMPT=3Dy sanity checks. Preventing the "disabled by BIOS" error message from reporting the wrong CPU is largely a bonus, as ensuring a stable CPU during module load is a non-goal for KVM. Link: https://lore.kernel.org/all/ZAdxNgv0M6P63odE@google.com Cc: Kai Huang Cc: Chao Gao Signed-off-by: Sean Christopherson Reviewed-by: Kai Huang --- arch/x86/kvm/svm/svm.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index b347173b4e29..cf5f3880751b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -523,18 +523,20 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu) vcpu->arch.osvw.status |=3D 1; } =20 -static bool kvm_is_svm_supported(void) +static bool __kvm_is_svm_supported(void) { - int cpu =3D raw_smp_processor_id(); + int cpu =3D smp_processor_id(); + struct cpuinfo_x86 *c =3D &cpu_data(cpu); + u64 vm_cr; =20 - if (boot_cpu_data.x86_vendor !=3D X86_VENDOR_AMD && - boot_cpu_data.x86_vendor !=3D X86_VENDOR_HYGON) { + if (c->x86_vendor !=3D X86_VENDOR_AMD && + c->x86_vendor !=3D X86_VENDOR_HYGON) { pr_err("CPU %d isn't AMD or Hygon\n", cpu); return false; } =20 - if (!boot_cpu_has(X86_FEATURE_SVM)) { + if (!cpu_has(c, X86_FEATURE_SVM)) { pr_err("SVM not supported by CPU %d\n", cpu); return false; } @@ -553,9 +555,20 @@ static bool kvm_is_svm_supported(void) return true; } =20 +static bool kvm_is_svm_supported(void) +{ + bool supported; + + migrate_disable(); + supported =3D __kvm_is_svm_supported(); + migrate_enable(); + + return supported; +} + static int svm_check_processor_compat(void) { - if (!kvm_is_svm_supported()) + if (!__kvm_is_svm_supported()) return -EIO; =20 return 0; --=20 2.40.1.606.ga4b1b128d6-goog