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=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 008E6C48BCD for ; Wed, 9 Jun 2021 23:43:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD25661249 for ; Wed, 9 Jun 2021 23:43:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230255AbhFIXp0 (ORCPT ); Wed, 9 Jun 2021 19:45:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbhFIXpM (ORCPT ); Wed, 9 Jun 2021 19:45:12 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB842C061280 for ; Wed, 9 Jun 2021 16:43:15 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id b20-20020ac87fd40000b02901e1370c5e12so12478066qtk.17 for ; Wed, 09 Jun 2021 16:43:15 -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=AvlzpSEIa9aM5YGGjLq2zoHFMvduDK875CtYDd8dUL4=; b=ifbBgdC2nQ37DNJxiu2U2mgYs0uHPbXMIH2n+cwuFFAH3iKBe0qhAO5/HRlTdd/4gs weRLHdWGD9UbIn2pAQUz8rHljyeUxKHvtCbS+xVYvJCSnDe3dxpRkMXraJCLh/gyvhm5 5yrTTOtc7Mny/qg/Gj7Vg4/nOw02qcWhgnsgPkIwueGb2ZabKjxzssvPCtXkp60CfKFE PmoQ45l64W4zQkJrONpN53AUoSBmF7Je3yLzxcZ5RUwEZrYHZLNwDeyGtEeFMYv0WR6g HNk4IRb6Qsrddzx8dVSpTL71KipzEdzcFYuM1HCXzJ5Hg6kSObAN4k3pBurFUMN3geqe de7w== 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=AvlzpSEIa9aM5YGGjLq2zoHFMvduDK875CtYDd8dUL4=; b=bC3PSU1x6+X7ekqNBn/w+zlYdqxLeDDhy8KIXCKIlR7sRGkbc4U+FdjApyrCalaFZ3 W7xL2hk3hGZc7NX8Z16i2iAtcea5BWlNYGshL8Jm1VicThzRzkzaA2STpaQDcR6z6DEX JGuTAYnVNjiistasbNhMVxwcIVTXA9F89SNyNZZb6d4mI7lgC6FjQD1bdla9tJd1GRv7 N38B6HEJPDJlO+OuMo5DoGxxu57EAiLjehJAPG571c4Kmq+4JSSHKfbR8n7ekvA6XcZF 3NI9txt9YRr7LPUXJGz7PqHG+DmSn4HiQyCef7uMiY+JtHBohZP0SSgdEnPS65Myc+Wd 9yuw== X-Gm-Message-State: AOAM532HIAt4UohSMlQhdUjkt+8/dI7TKTdT3iQpZghcXQLcxyspjUaJ dOJwqbV5rMX74U6Zvi7EhpNYBLB4NY4= X-Google-Smtp-Source: ABdhPJx232hNBWou88XddItzp4JVduww7ZRV8rUjKiIgDLbiXVcQWPYtOjEGIKR1VhkY6bLEHvW6mLXOC/U= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:8daf:e5e:ae50:4f28]) (user=seanjc job=sendgmr) by 2002:ad4:576e:: with SMTP id r14mr2569384qvx.61.1623282195011; Wed, 09 Jun 2021 16:43:15 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 9 Jun 2021 16:42:34 -0700 In-Reply-To: <20210609234235.1244004-1-seanjc@google.com> Message-Id: <20210609234235.1244004-15-seanjc@google.com> Mime-Version: 1.0 References: <20210609234235.1244004-1-seanjc@google.com> X-Mailer: git-send-email 2.32.0.rc1.229.g3e70b5a671-goog Subject: [PATCH 14/15] KVM: nVMX: WARN if subtly-impossible VMFUNC conditions occur From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Junaid Shahid , Maxim Levitsky , Lai Jiangshan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org WARN and inject #UD when emulating VMFUNC for L2 if the function is out-of-bounds or if VMFUNC is not enabled in vmcs12. Neither condition should occur in practice, as the CPU is supposed to prioritize the #UD over VM-Exit for out-of-bounds input and KVM is supposed to enable VMFUNC in vmcs02 if and only if it's enabled in vmcs12, but neither of those dependencies is obvious. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f686618d9ede..0075d3f0f8fa 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5494,6 +5494,16 @@ static int handle_vmfunc(struct kvm_vcpu *vcpu) } vmcs12 = get_vmcs12(vcpu); + + /* + * #UD on out-of-bounds function has priority over VM-Exit, and VMFUNC + * is enabled in vmcs02 if and only if it's enabled in vmcs12. + */ + if (WARN_ON_ONCE((function > 63) || !nested_cpu_has_vmfunc(vmcs12))) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 1; + } + if (!(vmcs12->vm_function_control & BIT_ULL(function))) goto fail; -- 2.32.0.rc1.229.g3e70b5a671-goog