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=-23.3 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_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 AEBBFC433E0 for ; Tue, 23 Feb 2021 22:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76D8564E22 for ; Tue, 23 Feb 2021 22:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232267AbhBWWzQ (ORCPT ); Tue, 23 Feb 2021 17:55:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233544AbhBWWwL (ORCPT ); Tue, 23 Feb 2021 17:52:11 -0500 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6951C061786 for ; Tue, 23 Feb 2021 14:51:30 -0800 (PST) Received: by mail-pf1-x42e.google.com with SMTP id q20so9784137pfu.8 for ; Tue, 23 Feb 2021 14:51:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ttBsWjyLSVhAbB5Dr48jKcxza7yyyr0KgTN3fQrwYqc=; b=peI5aM6IZ95/RV+lZK+vuJZJEWrN2dJDppCY0s5O5C1eMe/u0uGvUdXrucQPBOssY7 ut22yq4EIIR8hbLTUEzQ3gTJ22xM/q+qro0cq5v0HVjjD0wJLIXUVge9PppWRO3FQX2z j6pL7xHwxsVI/haWeP9LVgX/rwaeHjrJJf1Vt2MhihwW2NgzwhGLm/8yWgCUShAbycWc cRbZPKOujYMDRiQ2AiE7fjMtL5bFDErZ5PuK6Rdp0YXLTKTVr5q0XLthLm0zR/oNFjlL nYpKHwhXjeXLaSyi8gGtBmfrSeR7NBPQdqc73OGwwqhXcZp4IrDTDO9sgpyoxrzNPrFT o4cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ttBsWjyLSVhAbB5Dr48jKcxza7yyyr0KgTN3fQrwYqc=; b=Z3cl5SnOH+oBQgBMQFBrKWUn0L+k09VLASRejoq6e66EaaPE+nNZp/I077l/LyeSYq 3+vI9zhw670wvCYK/Ibat5NRCllO4k01243BbyOUVWcZSXLJ93gSJsOqkwEvqVXPiHn4 FoZu9IPuFhJGK3vQhzxMbNGmfTsZgd+BPh38s8zLYJ3IHruQZf08rP0IxUyUboiQMBup Oydk+BLn1a+7PA3gTB0HWGmpdkhF8OMyfE0weyuVwTh8GkjUsDQa+DhHH6MQi55jFakn kSSXuwN5K8uEButb6XrzOQDB/pzfMDrygv0n9jGXDqXW4QBZIqL0nNDsgSO0KsvrCtJI Wawg== X-Gm-Message-State: AOAM533FUo8whiGPTTAEChrgEFlZ4xesVQPTOR7cdItf2hTmkeJxsnpu A1VQ/IyPfJOYWcKKlmv/u9pTxqjHQGzEKg== X-Google-Smtp-Source: ABdhPJyv/nNxjK2cfks0xqxZ7ShsLpN+vjAq8wBNnw/7e9+HFI8TGSySz9yIOROT3agpGQdIy/HWUQ== X-Received: by 2002:aa7:94b7:0:b029:1ed:c7e8:d7f3 with SMTP id a23-20020aa794b70000b02901edc7e8d7f3mr7062926pfl.28.1614120690132; Tue, 23 Feb 2021 14:51:30 -0800 (PST) Received: from google.com ([2620:15c:f:10:c939:813f:76bc:d651]) by smtp.gmail.com with ESMTPSA id d189sm223746pfd.42.2021.02.23.14.51.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Feb 2021 14:51:29 -0800 (PST) Date: Tue, 23 Feb 2021 14:51:19 -0800 From: Sean Christopherson To: David Edmondson Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" , Joerg Roedel , x86@kernel.org, Thomas Gleixner , kvm@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Ingo Molnar , Jim Mattson , Borislav Petkov , Vitaly Kuznetsov Subject: Re: [PATCH v2 1/3] KVM: x86: dump_vmcs should not assume GUEST_IA32_EFER is valid Message-ID: References: <20210219144632.2288189-1-david.edmondson@oracle.com> <20210219144632.2288189-2-david.edmondson@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210219144632.2288189-2-david.edmondson@oracle.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Feb 19, 2021, David Edmondson wrote: > If the VM entry/exit controls for loading/saving MSR_EFER are either > not available (an older processor or explicitly disabled) or not > used (host and guest values are the same), reading GUEST_IA32_EFER > from the VMCS returns an inaccurate value. > > Because of this, in dump_vmcs() don't use GUEST_IA32_EFER to decide > whether to print the PDPTRs - do so if the EPT is in use and CR4.PAE > is set. This isn't necessarily correct either. In a way, it's less correct as PDPTRs are more likely to be printed when they shouldn't, assuming most guests are 64-bit guests. It's annoying to calculate the effective guest EFER, but so awful that it's worth risking confusion over PDTPRs. > Fixes: 4eb64dce8d0a ("KVM: x86: dump VMCS on invalid entry") > Signed-off-by: David Edmondson > --- > arch/x86/kvm/vmx/vmx.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index eb69fef57485..818051c9fa10 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -5759,7 +5759,6 @@ void dump_vmcs(void) > u32 vmentry_ctl, vmexit_ctl; > u32 cpu_based_exec_ctrl, pin_based_exec_ctrl, secondary_exec_control; > unsigned long cr4; > - u64 efer; > > if (!dump_invalid_vmcs) { > pr_warn_ratelimited("set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state.\n"); > @@ -5771,7 +5770,6 @@ void dump_vmcs(void) > cpu_based_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); > pin_based_exec_ctrl = vmcs_read32(PIN_BASED_VM_EXEC_CONTROL); > cr4 = vmcs_readl(GUEST_CR4); > - efer = vmcs_read64(GUEST_IA32_EFER); > secondary_exec_control = 0; > if (cpu_has_secondary_exec_ctrls()) > secondary_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); > @@ -5784,8 +5782,7 @@ void dump_vmcs(void) > cr4, vmcs_readl(CR4_READ_SHADOW), vmcs_readl(CR4_GUEST_HOST_MASK)); > pr_err("CR3 = 0x%016lx\n", vmcs_readl(GUEST_CR3)); > if ((secondary_exec_control & SECONDARY_EXEC_ENABLE_EPT) && > - (cr4 & X86_CR4_PAE) && !(efer & EFER_LMA)) > - { > + (cr4 & X86_CR4_PAE)) { > pr_err("PDPTR0 = 0x%016llx PDPTR1 = 0x%016llx\n", > vmcs_read64(GUEST_PDPTR0), vmcs_read64(GUEST_PDPTR1)); > pr_err("PDPTR2 = 0x%016llx PDPTR3 = 0x%016llx\n", > @@ -5811,7 +5808,8 @@ void dump_vmcs(void) > if ((vmexit_ctl & (VM_EXIT_SAVE_IA32_PAT | VM_EXIT_SAVE_IA32_EFER)) || > (vmentry_ctl & (VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_IA32_EFER))) > pr_err("EFER = 0x%016llx PAT = 0x%016llx\n", > - efer, vmcs_read64(GUEST_IA32_PAT)); > + vmcs_read64(GUEST_IA32_EFER), > + vmcs_read64(GUEST_IA32_PAT)); > pr_err("DebugCtl = 0x%016llx DebugExceptions = 0x%016lx\n", > vmcs_read64(GUEST_IA32_DEBUGCTL), > vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS)); > -- > 2.30.0 >