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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B34E3C433FE for ; Thu, 20 Jan 2022 01:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358066AbiATBHe (ORCPT ); Wed, 19 Jan 2022 20:07:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358031AbiATBH1 (ORCPT ); Wed, 19 Jan 2022 20:07:27 -0500 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 8E14DC061574 for ; Wed, 19 Jan 2022 17:07:27 -0800 (PST) Received: by mail-pj1-x104a.google.com with SMTP id i2-20020a17090a4b8200b001b426d8be4eso2929888pjh.4 for ; Wed, 19 Jan 2022 17:07:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=Juh5ZOlMsSeAWLXziqBZ7hfTYcz1GBOOW6Gc4QgkpAc=; b=GtfeymlahDJq8GbLIHsgKU1pkM/psWDB6FaaA9uBAH4K1H+aRW5dwP8RdupCLpWoDT oYxl+VfEKCriqB+z5dTojuQILPK1pdmyAQSapnqeyW5E1HUpfyt4YfDuA4k5hMDsek8l ud8FQv5Gm5rps/XrixIn5418PNQU1F4D1LgNwJuQnBnvRRXOi695Mg1TsIio58wyzAJy r6a2D76teZ9oIwqMEfSZvzJpixH4NVQ7YdnpiSB+dqviU8jFhba12o+8FcZ3f5Aczhxq Y8hNBdXjhDMKUJq9UrDFQ3Aw++XstSFNEdDdZALzH72fR6rSpYt2El5zMBsKyMMAkYuH AVtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=Juh5ZOlMsSeAWLXziqBZ7hfTYcz1GBOOW6Gc4QgkpAc=; b=nQyvf2Rbcq5UcnCFZDpSadYHuDOK623LQr86iAAstl+yAP+N0GcBtkmOChvts715Po DrgbUv1RpNwnt1DTDTJpVZ0JOP8nm+zswPUt7A2EB0NjSvms7DHyGN44qwlpDHaR7ozR uNxxMlFCZQajO1jxynSZfrBTLsYKeJPsYlwnNHOKUchxU4jJPZOY/dnBzTMngEv2xcwU jJzPN+5vVGWHncDpTKGFzTrYnQ6/2xEsQXhIIsATANjfEpSoGFXeI4j4hIWMQRxj1ic6 ledSCZHm05XErzxQ9p3vZsRHLxCQmvMf3temTHpwSBq1sGreATC0EOmHaArkrQ4JJpuj dk2Q== X-Gm-Message-State: AOAM5335+0zqvmMCNII5DXMGdwZHEzlqzS7J6IJVwd60ZV3ug27u+B36 Hg1lOoCoH3gYWBA2NQ/JtBq2eaQxn+c= X-Google-Smtp-Source: ABdhPJzjjAsbw39gYVbrNDfA6srZk5+ykqTMw++E0hDvNbPZ/Nf/6L8kjhpSLEzx25PIbPON7JqSCpN2hko= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a63:d044:: with SMTP id s4mr15422908pgi.350.1642640847082; Wed, 19 Jan 2022 17:07:27 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 20 Jan 2022 01:07:12 +0000 In-Reply-To: <20220120010719.711476-1-seanjc@google.com> Message-Id: <20220120010719.711476-3-seanjc@google.com> Mime-Version: 1.0 References: <20220120010719.711476-1-seanjc@google.com> X-Mailer: git-send-email 2.34.1.703.g22d0c6ccf7-goog Subject: [PATCH 2/9] Revert "KVM: SVM: avoid infinite loop on NPF from bad address" 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, Tom Lendacky , Brijesh Singh , Liam Merwick Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Revert a completely broken check on an "invalid" RIP in SVM's workaround for the DecodeAssists SMAP errata. kvm_vcpu_gfn_to_memslot() obviously expects a gfn, i.e. operates in the guest physical address space, whereas RIP is a virtual (not even linear) address. The "fix" worked for the problematic KVM selftest because the test identity mapped RIP. Fully revert the hack instead of trying to translate RIP to a GPA, as the non-SEV case is now handled earlier, and KVM cannot access guest page tables to translate RIP. This reverts commit e72436bc3a5206f95bb384e741154166ddb3202e. Fixes: e72436bc3a52 ("KVM: SVM: avoid infinite loop on NPF from bad address") Reported-by: Liam Merwick Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/svm.c | 7 ------- virt/kvm/kvm_main.c | 1 - 2 files changed, 8 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index aa1649b8cd8f..85703145eb0a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4311,13 +4311,6 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i if (likely(!insn || insn_len)) return true; - /* - * If RIP is invalid, go ahead with emulation which will cause an - * internal error exit. - */ - if (!kvm_vcpu_gfn_to_memslot(vcpu, kvm_rip_read(vcpu) >> PAGE_SHIFT)) - return true; - cr4 = kvm_read_cr4(vcpu); smep = cr4 & X86_CR4_SMEP; smap = cr4 & X86_CR4_SMAP; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5a1164483e6c..0bacecda79cf 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2248,7 +2248,6 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn return NULL; } -EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot); bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { -- 2.34.1.703.g22d0c6ccf7-goog