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_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 A49ADC43441 for ; Sun, 25 Nov 2018 17:53:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6552C20868 for ; Sun, 25 Nov 2018 17:53:35 +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="NcnOeI0i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6552C20868 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726703AbeKZEpF (ORCPT ); Sun, 25 Nov 2018 23:45:05 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:34244 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726317AbeKZEpF (ORCPT ); Sun, 25 Nov 2018 23:45:05 -0500 Received: by mail-wr1-f65.google.com with SMTP id j2so16609020wrw.1; Sun, 25 Nov 2018 09:53:28 -0800 (PST) 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=yXyfxlHiscoB2pEHT0Kz/2KXkbcS+v3fIbVqvZTxy0c=; b=NcnOeI0ir6i1mhWv6A7Scn2vFu5e/tNHUq5BIv+b4yJKnTFAimXUfoMmhGsDuQ+SOZ aUgrL8zzCsp9j7uoyWpln73aukRkQj1NOizEniyRBAtJuTE85bK+HWA4NW8Rm57NEBGZ INlPdyRK5WbRS9JjBo+oME/kiTqRNlmyeNKYodPFWRFv/znEN0waOJMWQf0FP4ZBSGdO KuuLSjdE0ysn3vJhfeq8qBiI+kwa6IOpziG8XCv0bXEUTBAe3Qkc263KX46LO6NSqkM1 JqKmC+/UQlGR1g4iWsfFPXHTCE4alTLuQobvxFdNrwyKrfNFih18E/layGGFA6S+McsA H5fw== 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=yXyfxlHiscoB2pEHT0Kz/2KXkbcS+v3fIbVqvZTxy0c=; b=Ytmh4D2Z0kvKsL+GDnU5taG4jW/8ofBNsvqBlhaiTEFE+P/ZrjqWQw2XDqbzFvMZeV 6QdVCpKc7xumBwJx2w4eHM6TecQLYpnhOphM7sCS3YwzlrvjqB5KDPptqDUp7CN2uBM+ 7lUpDgqMhC9797axKjOro1iYxv/8xW+V5lLDO2B8lt5PZY8XIZRNPb0a0qFKbeEsFFwH nGEjXZjoMWs5uZDXYXQsm+911pdwK9ckxKzZvYKMltGbzUfuPP2Lchs3+zDd9xCNyFeI 2NyQ09HmHkX9mJQcB60a/QFZPx7RBUV3iKDoshPcj0xB6X1QLx2hVPHudizOv737k9lU QXlg== X-Gm-Message-State: AA+aEWaWXf4gZowtcKsEm6LgbaF71USYDx/vG05c8UaQhwdHdiv9Ov3U p9IDfQRkiQeaNcuaGrpS1tfVhOyQ X-Google-Smtp-Source: AFSGD/WNo0ooBYFsiT/wMRbaCG0ZBSIp/87UEls8lJ2cgk5KCKLiaP5Je9KgpkvtqAxZJY4X9xoLBg== X-Received: by 2002:adf:db01:: with SMTP id s1mr5252840wri.214.1543168407774; Sun, 25 Nov 2018 09:53:27 -0800 (PST) Received: from 640k.lan ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id 6-v6sm10018766wmd.45.2018.11.25.09.53.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 25 Nov 2018 09:53:27 -0800 (PST) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Liran Alon , Jim Mattson Subject: [PATCH] KVM: x86: Trace changes to active TSC offset regardless if vCPU in guest-mode Date: Sun, 25 Nov 2018 18:53:25 +0100 Message-Id: <1543168405-16768-1-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 For some reason, kvm_x86_ops->write_l1_tsc_offset() skipped trace of change to active TSC offset in case vCPU is in guest-mode. This patch changes write_l1_tsc_offset() behavior to trace any change to active TSC offset to aid debugging. The VMX code is changed to look more similar to SVM, which is in my opinion nicer. Based on a patch by Liran Alon. Signed-off-by: Paolo Bonzini --- Untested still, but throwing it out because it seems pretty obvious... arch/x86/kvm/svm.c | 9 +++++---- arch/x86/kvm/vmx.c | 34 +++++++++++++++++----------------- 2 files changed, 22 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a24733aade4c..0d1a74069a9e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1456,10 +1456,11 @@ static u64 svm_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) g_tsc_offset = svm->vmcb->control.tsc_offset - svm->nested.hsave->control.tsc_offset; svm->nested.hsave->control.tsc_offset = offset; - } else - trace_kvm_write_tsc_offset(vcpu->vcpu_id, - svm->vmcb->control.tsc_offset, - offset); + } + + trace_kvm_write_tsc_offset(vcpu->vcpu_id, + svm->vmcb->control.tsc_offset - g_tsc_offset, + offset); svm->vmcb->control.tsc_offset = offset + g_tsc_offset; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 764c23dc444f..e7d3f7d35355 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3466,24 +3466,24 @@ static u64 vmx_read_l1_tsc_offset(struct kvm_vcpu *vcpu) static u64 vmx_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { - u64 active_offset = offset; - if (is_guest_mode(vcpu)) { - /* - * We're here if L1 chose not to trap WRMSR to TSC. According - * to the spec, this should set L1's TSC; The offset that L1 - * set for L2 remains unchanged, and still needs to be added - * to the newly set TSC to get L2's TSC. - */ - struct vmcs12 *vmcs12 = get_vmcs12(vcpu); - if (nested_cpu_has(vmcs12, CPU_BASED_USE_TSC_OFFSETING)) - active_offset += vmcs12->tsc_offset; - } else { - trace_kvm_write_tsc_offset(vcpu->vcpu_id, - vmcs_read64(TSC_OFFSET), offset); - } + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + u64 g_tsc_offset = 0; + + /* + * We're here if L1 chose not to trap WRMSR to TSC. According + * to the spec, this should set L1's TSC; The offset that L1 + * set for L2 remains unchanged, and still needs to be added + * to the newly set TSC to get L2's TSC. + */ + if (is_guest_mode(vcpu) && + (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)) + g_tsc_offset = vmcs12->tsc_offset; - vmcs_write64(TSC_OFFSET, active_offset); - return active_offset; + trace_kvm_write_tsc_offset(vcpu->vcpu_id, + vcpu->arch.tsc_offset - g_tsc_offset, + offset); + vmcs_write64(TSC_OFFSET, offset + g_tsc_offset); + return offset + g_tsc_offset; } /* -- 1.8.3.1