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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E9EEEC43603 for ; Fri, 6 Dec 2019 23:46:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A986C20409 for ; Fri, 6 Dec 2019 23:46:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Q/Bw9UGv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726403AbfLFXqs (ORCPT ); Fri, 6 Dec 2019 18:46:48 -0500 Received: from mail-pf1-f202.google.com ([209.85.210.202]:56765 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726375AbfLFXqs (ORCPT ); Fri, 6 Dec 2019 18:46:48 -0500 Received: by mail-pf1-f202.google.com with SMTP id j7so4902318pfh.23 for ; Fri, 06 Dec 2019 15:46:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=y+19aKtY4EbBtyHli0gL/tj0TPv6Yayq8480kA5pLQM=; b=Q/Bw9UGvsan3MQgEECqz5rz8WNiHQEfJ9kQVCGEQJqiYZdN7EDRRj2X9oq/NNxRUtr amcDCuTnkR0lUSzstsIOxo6y7T78WJy7hAaaQPu05YDA/fKXw82dswmVSKaBlnkKAGVe ozjXPj8xxtwL0hT62VcpZy35c4qnKsdgPi0UMxs/O2zPveISWYffhdL4QEhUQfiCNMUy wj4TZWZXDCebqRab7X9L0J4aQKWJPTezfu0gb7bU6FzEjKbZXkkBO10Tg42sopP6ZK/0 oMpcc2oiGxodgrKgg+RxYiFJidXtD2PDpRBuILvyyMIMI3S2HMZuUGdQV8MFKADdQd8r D0mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=y+19aKtY4EbBtyHli0gL/tj0TPv6Yayq8480kA5pLQM=; b=FSHe5SFUiE5JNC3J+3pzDaoQd9PXJGf8vwSoRwo01A+ZtvKwXgqJpp7mQaT5CEF9CM thr2k0UrgeBcF4jzVwJrtqtVZ27L0eL+uVk4MzvJ14AToxXGyUZP8xUuHha6aQomTR2s qd87t+bsktFgPiy2YEnlVSI/aYwVrDsygAS8OyMlpYzkMF8ZwrToYdMNYybQdr3g8XEj Y57Le7ydFhGpP3yyXAUXaD4JUai9fYRbcb7Fm0vqRzTRFgAO1gfsJneC8YGfmhaVM/Oc k7EOayJRDa4vRev1jgNtNDqfzM073Nb7clZaTyZj5Vd8gzGusVEXFhTQ8fZCOC5FTBkH ocJg== X-Gm-Message-State: APjAAAX92URGL3KoBtwbnJjYrPWUs9o+neTJk959QW+siQ8+3mp70rgh m5W7WkCOR4OYK0+MBryZLAWfkin7BAeilvJnV8xYSvUH/BseZYQbwcz5CcsbGnvEevckvpcwbtP 7pZvpDJhNSHNMreZ1Gj/5omfMn5kF8XjnYhxqeImHhuQqEn6QtfGkbxAHEUazSqQ= X-Google-Smtp-Source: APXvYqw39BeYdk7jH0zVdelpeLBdC4zRpUvP8KvdtXmV8mrLSW6bHeCDxEGMuQ6TUkxHkClH+aJItPWkuaLCwQ== X-Received: by 2002:a63:7311:: with SMTP id o17mr6103845pgc.29.1575676007030; Fri, 06 Dec 2019 15:46:47 -0800 (PST) Date: Fri, 6 Dec 2019 15:46:35 -0800 Message-Id: <20191206234637.237698-1-jmattson@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog Subject: [PATCH v3 1/3] kvm: nVMX: VMWRITE checks VMCS-link pointer before VMCS field From: Jim Mattson To: kvm@vger.kernel.org Cc: Jim Mattson , Liran Alon , Paolo Bonzini , Vitaly Kuznetsov , Peter Shier , Oliver Upton , Jon Cargille Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org According to the SDM, a VMWRITE in VMX non-root operation with an invalid VMCS-link pointer results in VMfailInvalid before the validity of the VMCS field in the secondary source operand is checked. For consistency, modify both handle_vmwrite and handle_vmread, even though there was no problem with the latter. Fixes: 6d894f498f5d1 ("KVM: nVMX: vmread/vmwrite: Use shadow vmcs12 if running L2") Signed-off-by: Jim Mattson Cc: Liran Alon Cc: Paolo Bonzini Cc: Vitaly Kuznetsov Reviewed-by: Peter Shier Reviewed-by: Oliver Upton Reviewed-by: Jon Cargille --- v1 -> v2: * Split the invalid VMCS-link pointer check from the conditional call to copy_vmcs02_to_vmcs12_rare. * Hoisted the assignment of vmcs12 to its declaration. * Modified handle_vmread to maintain consistency with handle_vmwrite. v2 -> v3: * No changes arch/x86/kvm/vmx/nested.c | 59 +++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 34 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 4aea7d304beb..ee1bf9710e86 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4753,32 +4753,28 @@ static int handle_vmread(struct kvm_vcpu *vcpu) { unsigned long field; u64 field_value; + struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); int len; gva_t gva = 0; - struct vmcs12 *vmcs12; + struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu) + : get_vmcs12(vcpu); struct x86_exception e; short offset; if (!nested_vmx_check_permission(vcpu)) return 1; - if (to_vmx(vcpu)->nested.current_vmptr == -1ull) + /* + * In VMX non-root operation, when the VMCS-link pointer is -1ull, + * any VMREAD sets the ALU flags for VMfailInvalid. + */ + if (vmx->nested.current_vmptr == -1ull || + (is_guest_mode(vcpu) && + get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)) return nested_vmx_failInvalid(vcpu); - if (!is_guest_mode(vcpu)) - vmcs12 = get_vmcs12(vcpu); - else { - /* - * When vmcs->vmcs_link_pointer is -1ull, any VMREAD - * to shadowed-field sets the ALU flags for VMfailInvalid. - */ - if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull) - return nested_vmx_failInvalid(vcpu); - vmcs12 = get_shadow_vmcs12(vcpu); - } - /* Decode instruction info and find the field to read */ field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf)); @@ -4855,13 +4851,20 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) */ u64 field_value = 0; struct x86_exception e; - struct vmcs12 *vmcs12; + struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu) + : get_vmcs12(vcpu); short offset; if (!nested_vmx_check_permission(vcpu)) return 1; - if (vmx->nested.current_vmptr == -1ull) + /* + * In VMX non-root operation, when the VMCS-link pointer is -1ull, + * any VMWRITE sets the ALU flags for VMfailInvalid. + */ + if (vmx->nested.current_vmptr == -1ull || + (is_guest_mode(vcpu) && + get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)) return nested_vmx_failInvalid(vcpu); if (vmx_instruction_info & (1u << 10)) @@ -4889,24 +4892,12 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) return nested_vmx_failValid(vcpu, VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT); - if (!is_guest_mode(vcpu)) { - vmcs12 = get_vmcs12(vcpu); - - /* - * Ensure vmcs12 is up-to-date before any VMWRITE that dirties - * vmcs12, else we may crush a field or consume a stale value. - */ - if (!is_shadow_field_rw(field)) - copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12); - } else { - /* - * When vmcs->vmcs_link_pointer is -1ull, any VMWRITE - * to shadowed-field sets the ALU flags for VMfailInvalid. - */ - if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull) - return nested_vmx_failInvalid(vcpu); - vmcs12 = get_shadow_vmcs12(vcpu); - } + /* + * Ensure vmcs12 is up-to-date before any VMWRITE that dirties + * vmcs12, else we may crush a field or consume a stale value. + */ + if (!is_guest_mode(vcpu) && !is_shadow_field_rw(field)) + copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12); offset = vmcs_field_to_offset(field); if (offset < 0) -- 2.24.0.393.g34dc348eaf-goog