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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 B7959C04AAC for ; Mon, 20 May 2019 13:41:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A55020856 for ; Mon, 20 May 2019 13:41:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sDqq3hBC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387619AbfETNlF (ORCPT ); Mon, 20 May 2019 09:41:05 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:46001 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727682AbfETNlF (ORCPT ); Mon, 20 May 2019 09:41:05 -0400 Received: by mail-wr1-f67.google.com with SMTP id b18so14616774wrq.12; Mon, 20 May 2019 06:41:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; bh=pxalDK/lEAAA1vrNRXNOUg51uWf8D/bvJySintxZsSI=; b=sDqq3hBCW4e/iFe8vPihu6wBp7wJU6ShXhgEpFEvr3FGKUbW/Vp81aX2Zll29j/w8i +3qz03FIW2jdao+8cYdxcaVDr2jpU3cNhHjgqf7oN3/ROvkxm0DPge4KDtlf1DRdSp1o WqKwHZhXf/To2i0pZjA/YZ7eOfC0zDjDZ/+huerfEwMTUXF2ffbkls7hKdPCHWmENRW4 qQR5kGvWY698Enk0U/6Bwp1d/cwxi7PiLqMQVYuB2vV8ey/IOqe4MCneSxW9PDfp9wu1 nyF0T06qW20qmRghalcwruLza/+yGh/jkA74AvgWTgVs1DO+k3pPNQVQXrNGnESbg6Yn nvyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=pxalDK/lEAAA1vrNRXNOUg51uWf8D/bvJySintxZsSI=; b=Oo4TsZ6/JKapB0i+naUeU4EITwf3YWdUoMW5HVCvul0u9PAIBo6xj8d6NzYOo7KNvl UMG7p/n4HbAUrieiRoZDLTgAHJ3Rqz0gCMoiviaRuTBYq9x0rL9tPYS66k85x6R8/bwG IJn5QaUFinzYFwRSd19g2HMcnIXPg5MHx5E2RVVMQSCKAEQq7RH3LkTW1qq289HIXZ6s uaJAVasRkkmU+Ed6r/d7yiURUY88rCDqilyH5JaqLyTt5ItuyY7aTPxly0zmDj1m+xIv oCH/+sNaj7XzhKu0Xa1YzC18Neqgq9QamrSh7jWaoj4v7gkIadBxiDFf2y0GfrG7uM8E zIiQ== X-Gm-Message-State: APjAAAVRMXQEofPLOpxlPHrBfYf8WwCn8kiOxyyKRYSUe2ILsBFzSbU5 7ezwC/1WVbuohPOoj6ZUDUP0N3iY X-Google-Smtp-Source: APXvYqyBOcsBF+HdiA9JrCMkV89LroPQELkzqr/7WyslmZs2tAje8S03xg13C0Ym2UxJqbsqhDvbqQ== X-Received: by 2002:adf:cd09:: with SMTP id w9mr8854725wrm.242.1558359662928; Mon, 20 May 2019 06:41:02 -0700 (PDT) Received: from 640k.lan ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id a10sm20296423wrm.94.2019.05.20.06.41.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 20 May 2019 06:41:02 -0700 (PDT) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Sean Christopherson Subject: [PATCH] KVM: x86: do not spam dmesg with VMCS/VMCB dumps Date: Mon, 20 May 2019 15:41:01 +0200 Message-Id: <1558359661-17796-1-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Userspace can easily set up invalid processor state in such a way that dmesg will be filled with VMCS or VMCB dumps. Disable this by default using a module parameter. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm.c | 9 ++++++++- arch/x86/kvm/vmx/vmx.c | 26 +++++++++++++++++++------- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a9e553a1317f..735b8c01895e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -379,6 +379,9 @@ struct amd_svm_iommu_ir { static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT); module_param(sev, int, 0444); +static bool __read_mostly dump_invalid_vmcb = 0; +module_param(dump_invalid_vmcb, bool, 0644); + static u8 rsm_ins_bytes[] = "\x0f\xaa"; static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); @@ -4828,6 +4831,11 @@ static void dump_vmcb(struct kvm_vcpu *vcpu) struct vmcb_control_area *control = &svm->vmcb->control; struct vmcb_save_area *save = &svm->vmcb->save; + if (!dump_invalid_vmcb) { + pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n"); + return; + } + pr_err("VMCB Control Area:\n"); pr_err("%-20s%04x\n", "cr_read:", control->intercept_cr & 0xffff); pr_err("%-20s%04x\n", "cr_write:", control->intercept_cr >> 16); @@ -4986,7 +4994,6 @@ static int handle_exit(struct kvm_vcpu *vcpu) kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY; kvm_run->fail_entry.hardware_entry_failure_reason = svm->vmcb->control.exit_code; - pr_err("KVM: FAILED VMRUN WITH VMCB:\n"); dump_vmcb(vcpu); return 0; } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1ac167614032..b93e36ddee5e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -114,6 +114,9 @@ bool __read_mostly enable_pml = 1; module_param_named(pml, enable_pml, bool, S_IRUGO); +static bool __read_mostly dump_invalid_vmcs = 0; +module_param(dump_invalid_vmcs, bool, 0644); + #define MSR_BITMAP_MODE_X2APIC 1 #define MSR_BITMAP_MODE_X2APIC_APICV 2 @@ -5607,15 +5610,24 @@ static void vmx_dump_dtsel(char *name, uint32_t limit) void dump_vmcs(void) { - u32 vmentry_ctl = vmcs_read32(VM_ENTRY_CONTROLS); - u32 vmexit_ctl = vmcs_read32(VM_EXIT_CONTROLS); - u32 cpu_based_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); - u32 pin_based_exec_ctrl = vmcs_read32(PIN_BASED_VM_EXEC_CONTROL); - u32 secondary_exec_control = 0; - unsigned long cr4 = vmcs_readl(GUEST_CR4); - u64 efer = vmcs_read64(GUEST_IA32_EFER); + u32 vmentry_ctl, vmexit_ctl; + u32 cpu_based_exec_ctrl, pin_based_exec_ctrl, secondary_exec_control; + unsigned long cr4; + u64 efer; int i, n; + if (!dump_invalid_vmcs) { + pr_warn_ratelimited("set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state.\n"); + return; + } + + vmentry_ctl = vmcs_read32(VM_ENTRY_CONTROLS); + vmexit_ctl = vmcs_read32(VM_EXIT_CONTROLS); + 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); -- 1.8.3.1