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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 B9CCDC433E0 for ; Tue, 2 Feb 2021 10:51:58 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E061C64DAE for ; Tue, 2 Feb 2021 10:51:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E061C64DAE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59690 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l6tHo-000376-Um for qemu-devel@archiver.kernel.org; Tue, 02 Feb 2021 05:51:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54128) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6tH0-0002ey-Iq for qemu-devel@nongnu.org; Tue, 02 Feb 2021 05:51:06 -0500 Received: from indium.canonical.com ([91.189.90.7]:38844) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1l6tGy-0005gk-9K for qemu-devel@nongnu.org; Tue, 02 Feb 2021 05:51:06 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1l6tGp-0006Bk-Fu for ; Tue, 02 Feb 2021 10:50:55 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id A5C7B2E8139 for ; Tue, 2 Feb 2021 10:50:53 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 02 Feb 2021 10:42:22 -0000 From: ANIMESH KUMAR SINHA <1912777@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug: distribution=ubuntu; sourcepackage=None; component=None; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: animeshk th-huth X-Launchpad-Bug-Reporter: ANIMESH KUMAR SINHA (animeshk) X-Launchpad-Bug-Modifier: ANIMESH KUMAR SINHA (animeshk) References: <161131847021.10154.14606822070729811950.malonedeb@gac.canonical.com> Message-Id: <161226254293.24527.6684999666846790846.malone@wampee.canonical.com> Subject: [Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="3d7abcb776ec05aa0a89112accc21bf8b41dfc24"; Instance="production" X-Launchpad-Hash: 22caa384095c767505f29df5cc3638816290620f Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1912777 <1912777@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Could someone update on this? ** Changed in: qemu Status: Incomplete =3D> New -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 Status in QEMU: New Status in Ubuntu: New Bug description: I was able to generate trace dump in Qemu for kvm_run_exit event in both = QEMU 2.11.0 and QEMU 4.0.0 From the trace i noticed that the number of KVM_KXIT_MMIO calls has incre= ased alot and is causing delay in testcase execution. I executed same testcase from Qemu 2.11 and Qemu4. Inside Virtual machine when using qemu 2.11 testcase got completed in 11 = seconds but the same testcase when executed on Qemu 4.0.0 got executed in 26 seco= nds. = I did a bit of digging and extracted the kvm_run_exit to figure out whats= going on. Please find = Stats from Qemu2.11: KVM_EXIT_UNKNOWN : 0 KVM_EXIT_EXCEPTION : 0 KVM_EXIT_IO : 182513 KVM_EXIT_HYPERCALL : 0 KVM_EXIT_DEBUG : 0 KVM_EXIT_HLT : 0 KVM_EXIT_MMIO : 216701 KVM_EXIT_IRQ_WINDOW_OPEN : 0 KVM_EXIT_SHUTDOWN : 0 KVM_EXIT_FAIL_ENTRY : 0 KVM_EXIT_INTR : 0 KVM_EXIT_SET_TPR : 0 KVM_EXIT_TPR_ACCESS : 0 KVM_EXIT_S390_SIEIC : 0 KVM_EXIT_S390_RESET : 0 KVM_EXIT_DCR : 0 KVM_EXIT_NMI : 0 KVM_EXIT_INTERNAL_ERROR : 0 KVM_EXIT_OSI : 0 KVM_EXIT_PAPR_HCALL : 0 KVM_EXIT_S390_UCONTROL : 0 KVM_EXIT_WATCHDOG : 0 KVM_EXIT_S390_TSCH : 0 KVM_EXIT_EPR : 0 KVM_EXIT_SYSTEM_EVENT : 0 KVM_EXIT_S390_STSI : 0 KVM_EXIT_IOAPIC_EOI : 0 KVM_EXIT_HYPERV : 0 KVM_RUN_EXIT : 399214 (Total in Qemu 2.11 for a testcase) = Stats For Qemu 4.0.0: VM_EXIT_UNKNOWN : 0 = = = KVM_EXIT_EXCEPTION : 0 = = = KVM_EXIT_IO : 163729 = = = KVM_EXIT_HYPERCALL : 0 = = = KVM_EXIT_DEBUG : 0 = = = KVM_EXIT_HLT : 0 = = = KVM_EXIT_MMIO : 1094231 = = = KVM_EXIT_IRQ_WINDOW_OPEN : 46 = = = KVM_EXIT_SHUTDOWN : 0 = = = KVM_EXIT_FAIL_ENTRY : 0 = = = KVM_EXIT_INTR : 0 = = = KVM_EXIT_SET_TPR : 0 = = = KVM_EXIT_TPR_ACCESS : 0 = = = KVM_EXIT_S390_SIEIC : 0 = = = KVM_EXIT_S390_RESET : 0 = = = KVM_EXIT_DCR : 0 = = = KVM_EXIT_NMI : 0 = = = KVM_EXIT_INTERNAL_ERROR : 0 = = = KVM_EXIT_OSI : 0 = = = KVM_EXIT_PAPR_HCALL : 0 = = = KVM_EXIT_S390_UCONTROL : 0 = = = KVM_EXIT_WATCHDOG : 0 = = = KVM_EXIT_S390_TSCH : 0 = = = KVM_EXIT_EPR : 0 = = = KVM_EXIT_SYSTEM_EVENT : 0 = = = KVM_EXIT_S390_STSI : 0 = = = KVM_EXIT_IOAPIC_EOI : 464 = = = KVM_EXIT_HYPERV : 0 = KVM_RUN_EXIT : 1258470 (Total in qemu 4.0.0 for same testcase) From above analysis i found that the number of KVM_EXIT_MMIO has increased by 4.x. Could someone from qemu community help me understand as to why the MMIO exits have increased in qemu4 ? The results i obtained are after running same testcase. On Qemu2.11 testcase gets completed in : 11seconds on Qemu4.11 testcase gets completed in : 26 seconds VM Qcow2 used in Ubuntu 16.04 VM kernel OS is : 4.4 generic = Let me know incase more information is required . To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions