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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 541C7C43460 for ; Wed, 19 May 2021 18:26:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2ECF7611BF for ; Wed, 19 May 2021 18:26:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbhESS1e (ORCPT ); Wed, 19 May 2021 14:27:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230062AbhESS1b (ORCPT ); Wed, 19 May 2021 14:27:31 -0400 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17D49C06175F; Wed, 19 May 2021 11:26:11 -0700 (PDT) Received: by mail-ej1-x632.google.com with SMTP id k14so17886137eji.2; Wed, 19 May 2021 11:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=eYCxITyk+mk4AUTz8nuEyzSBN6pUkGqdMoN9h/d6AUE=; b=uDU95HCW5Qxy8VJOwJvwjdYXBniziRNUCJwn9ULD+mtVcf7wYeECcFP9kEW6lMYiqK JI8jbZV1zNr/DhC43/txPUaZDBOlhFtOcc3ih8nBnkf5I1NWFFFCdUmMgQjss5ECubCC spmLgq6bDWGQIfYHPJV37x5v+NAvRNpr95XJf8LHj7mkxMz5w0T+gNwHFmzh24k6s2Iy qpZYOeHKi485gABYWsnlotZHGwiHlQAeQ4TFWOJYC3zOIeEwKFxmFqvmjyr7i/6xWZp+ ZPR6nfRqoHVTS8bsiFX8YV3cmNnhDeLvcm8beX2/c0rrPsDxOeppzmlA4OJTi9hWEJMy U9Ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=eYCxITyk+mk4AUTz8nuEyzSBN6pUkGqdMoN9h/d6AUE=; b=tB18/2j/jew2lUQDOHVwBkwatolMCV4vA1/yJyms94yIW5xBcU7FKfwJ5Wkk+eZv/M 8i7gh/nOGoL00/h9wOy4MncgIyi7O7fn+uRGdJ+TZk9dbRVKhgx9UtQPvF0GK6+goVM8 637LUik1VG5s+08JolILGrKn7PWRWNLEzT+0WEHIEwabdCzidafQkl/BG0R+pwqzu/eR q23SLKdOPliYemi4+4odvbXISIF/fLdTA5fVqK0WqTUDL/e3XjI49R+AiE9azymWt6B6 Q6JFxKIbzlV4XAua4ALiv5Lp5LwMQb9gm15SEMUmov5xrtXvY/THHhjOJy8FRNgdE4Pp GTqQ== X-Gm-Message-State: AOAM533PaNaNw9fvisNfrhigwfvlv7krEeQsW3bws4zBZ2PKcCZW22MS VD/MQUn8LZLcy6c2ChgpReurUlzj/S8= X-Google-Smtp-Source: ABdhPJxgUEjPkhULuMBxFAsG87dtJb8Gw0PbOWW/r4V4fZKj8KjnoPLTaB02KXnScf0EAoAAeLEBRg== X-Received: by 2002:a17:906:2a08:: with SMTP id j8mr433226eje.483.1621448769291; Wed, 19 May 2021 11:26:09 -0700 (PDT) Received: from localhost.localdomain.Home ([151.32.52.155]) by smtp.gmail.com with ESMTPSA id c3sm299843edn.16.2021.05.19.11.26.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 May 2021 11:26:08 -0700 (PDT) From: Stefano De Venuto To: linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, x86@kernel.org, hpa@zytor.com, kvm@vger.kernel.org, rostedt@goodmis.org, y.karadz@gmail.com, Stefano De Venuto , Dario Faggioli Subject: [PATCH] Move VMEnter and VMExit tracepoints closer to the actual event Date: Wed, 19 May 2021 20:23:03 +0200 Message-Id: <20210519182303.2790-1-stefano.devenuto99@gmail.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kvm_entry and kvm_exit tracepoints are still quite far from the actual VMEnters/VMExits. This means that in a trace we can find host events after a kvm_entry event and before a kvm_exit one, as in this example: trace.dat: CPU 0/KVM-4594 [001] 2.167191: kvm_entry: trace.dat: CPU 0/KVM-4594 [001] 2.167192: write_msr: 48, value 0 trace.dat: CPU 0/KVM-4594 [001] 2.167192: rcu_utilization: Start context switch trace.dat: CPU 0/KVM-4594 [001] 2.167192: rcu_utilization: End context switch trace-tumbleweed.dat: -0 [000] 2.167196: hrtimer_cancel: trace-tumbleweed.dat: -0 [000] 2.167197: hrtimer_expire_entry: trace-tumbleweed.dat: -0 [000] 2.167201: hrtimer_expire_exit: trace-tumbleweed.dat: -0 [000] 2.167201: hrtimer_start: trace.dat: CPU 0/KVM-4594 [001] 2.167203: read_msr: 48, value 0 trace.dat: CPU 0/KVM-4594 [001] 2.167203: write_msr: 48, value 4 trace.dat: CPU 0/KVM-4594 [001] 2.167204: kvm_exit: This patch moves the tracepoints closer to the events, for both Intel and AMD, so that a combined host-guest trace will offer a more realistic representation of what is really happening, as shown here: trace.dat: CPU 0/KVM-2553 [000] 2.190290: write_msr: 48, value 0 trace.dat: CPU 0/KVM-2553 [000] 2.190290: rcu_utilization: Start context switch trace.dat: CPU 0/KVM-2553 [000] 2.190290: rcu_utilization: End context switch trace.dat: CPU 0/KVM-2553 [000] 2.190290: kvm_entry: trace-tumbleweed.dat: -0 [000] 2.190290: write_msr: trace-tumbleweed.dat: -0 [000] 2.190290: cpu_idle: trace.dat: CPU 0/KVM-2553 [000] 2.190291: kvm_exit: trace.dat: CPU 0/KVM-2553 [000] 2.190291: read_msr: 48, value 0 trace.dat: CPU 0/KVM-2553 [000] 2.190291: write_msr: 48, value 4 Signed-off-by: Stefano De Venuto Signed-off-by: Dario Faggioli --- arch/x86/kvm/svm/svm.c | 8 ++++---- arch/x86/kvm/vmx/vmx.c | 10 +++++----- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 05eca131eaf2..c77d4866e239 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3275,8 +3275,6 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) struct kvm_run *kvm_run = vcpu->run; u32 exit_code = svm->vmcb->control.exit_code; - trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM); - /* SEV-ES guests must use the CR write traps to track CR registers. */ if (!sev_es_guest(vcpu->kvm)) { if (!svm_is_intercept(svm, INTERCEPT_CR0_WRITE)) @@ -3707,6 +3705,8 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) kvm_guest_enter_irqoff(); + trace_kvm_entry(vcpu); + if (sev_es_guest(vcpu->kvm)) { __svm_sev_es_vcpu_run(vmcb_pa); } else { @@ -3725,6 +3725,8 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) vmload(__sme_page_pa(sd->save_area)); } + trace_kvm_exit(svm->vmcb->control.exit_code, vcpu, KVM_ISA_SVM); + kvm_guest_exit_irqoff(); } @@ -3732,8 +3734,6 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); - trace_kvm_entry(vcpu); - svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX]; svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP]; svm->vmcb->save.rip = vcpu->arch.regs[VCPU_REGS_RIP]; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 4bceb5ca3a89..33c732101b83 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6661,6 +6661,8 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, { kvm_guest_enter_irqoff(); + trace_kvm_entry(vcpu); + /* L1D Flush includes CPU buffer clear to mitigate MDS */ if (static_branch_unlikely(&vmx_l1d_should_flush)) vmx_l1d_flush(vcpu); @@ -6675,6 +6677,9 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, vcpu->arch.cr2 = native_read_cr2(); + vmx->exit_reason.full = vmcs_read32(VM_EXIT_REASON); + trace_kvm_exit(vmx->exit_reason.full, vcpu, KVM_ISA_VMX); + kvm_guest_exit_irqoff(); } @@ -6693,8 +6698,6 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) if (vmx->emulation_required) return EXIT_FASTPATH_NONE; - trace_kvm_entry(vcpu); - if (vmx->ple_window_dirty) { vmx->ple_window_dirty = false; vmcs_write32(PLE_WINDOW, vmx->ple_window); @@ -6814,15 +6817,12 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) return EXIT_FASTPATH_NONE; } - vmx->exit_reason.full = vmcs_read32(VM_EXIT_REASON); if (unlikely((u16)vmx->exit_reason.basic == EXIT_REASON_MCE_DURING_VMENTRY)) kvm_machine_check(); if (likely(!vmx->exit_reason.failed_vmentry)) vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD); - trace_kvm_exit(vmx->exit_reason.full, vcpu, KVM_ISA_VMX); - if (unlikely(vmx->exit_reason.failed_vmentry)) return EXIT_FASTPATH_NONE; -- 2.31.1