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=-3.8 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 6B215C433DB for ; Fri, 22 Jan 2021 16:12:01 +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 E16E2206F6 for ; Fri, 22 Jan 2021 16:12:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E16E2206F6 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]:44758 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l2z2U-0000e6-Ro for qemu-devel@archiver.kernel.org; Fri, 22 Jan 2021 11:11:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47920) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l2z1W-0008Or-8C for qemu-devel@nongnu.org; Fri, 22 Jan 2021 11:10:58 -0500 Received: from indium.canonical.com ([91.189.90.7]:38530) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1l2z1U-0003Bo-2x for qemu-devel@nongnu.org; Fri, 22 Jan 2021 11:10:58 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1l2z1S-0004y0-2N for ; Fri, 22 Jan 2021 16:10:54 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 08AC82E8138 for ; Fri, 22 Jan 2021 16:10:54 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 22 Jan 2021 15:58:14 -0000 From: Thomas Huth <1912777@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Incomplete; 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: Thomas Huth (th-huth) References: <161131847021.10154.14606822070729811950.malonedeb@gac.canonical.com> Message-Id: <161133109488.29264.8902324205952319924.malone@soybean.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="2d1d5e352f0d063d660df2300e31f66bed027fa5"; Instance="production" X-Launchpad-Hash: 5777d82cfd903e7e916383291dcbc9ee61ba4411 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=0.249, 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" Can you provide a link to the test case that you used? Otherwise, can you try to bisect the problem? Can you please also try with the latest version of QEMU? v4.0 is rather old already. ** Information type changed from Public Security to Public ** Changed in: qemu Status: New =3D> Incomplete -- = 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: Incomplete 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