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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A42DDCAC5B9 for ; Tue, 30 Sep 2025 08:03:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3374110E145; Tue, 30 Sep 2025 08:03:53 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="nTeP0hJ2"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id F2D7089C83; Tue, 30 Sep 2025 08:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1759219432; x=1790755432; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=blP+1aXofxiRorje2aYnseFkYVpT/JKUFVCD4egWEjQ=; b=nTeP0hJ2krYH7p62iXjngQbDNZuWiEo7cf+Bk4SgK4qf/0ON0xBl6D76 2eFuPr9OCKvG+6EGAn4o1olUj7cdUI+L7p+IeHPQNf6DvQZYRzfZ6ugPm thC1XxY1gumSljRzM7gAY9/Hgf281VJBoZI4fuT/NxGWD2cQ5Vgktlje6 HZfBja28jVhI0dWDbH1Nwa0wFcJ966hg1eTgPGOn7f+tVTsWuJHLBsSfx PIe+EvfwOG5AQ2vuwg9a0CcC9l1aF5o96Te97ngebCZUbzcXoTShYji8R eBNWn3HGqn9MBPgBdQu1DE9xARDY976hcWUap1z9shpGd4Guhd9REllCf g==; X-CSE-ConnectionGUID: uPCdJpXASyuQuWPc1MX3Vg== X-CSE-MsgGUID: 98UFM6UMSrKMEqNJ8r0SrA== X-IronPort-AV: E=McAfee;i="6800,10657,11568"; a="61513025" X-IronPort-AV: E=Sophos;i="6.18,303,1751266800"; d="scan'208";a="61513025" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2025 01:03:51 -0700 X-CSE-ConnectionGUID: Kj2Zd/VZQyyjrU7daZGOAA== X-CSE-MsgGUID: NGO99cVCSIqbreozRJzEQQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,303,1751266800"; d="scan'208";a="182877217" Received: from dapengmi-mobl1.ccr.corp.intel.com (HELO [10.124.232.209]) ([10.124.232.209]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2025 01:03:48 -0700 Message-ID: <25af94f5-79e3-4005-964e-e77b1320a16e@linux.intel.com> Date: Tue, 30 Sep 2025 16:03:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: REGRESSION on linux-next (next-20250919) To: "Borah, Chaitanya Kumar" , seanjc@google.com Cc: "intel-gfx@lists.freedesktop.org" , "intel-xe@lists.freedesktop.org" , "Kurmi, Suresh Kumar" , "Saarinen, Jani" , lucas.demarchi@intel.com, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org References: <70b64347-2aca-4511-af78-a767d5fa8226@intel.com> Content-Language: en-US From: "Mi, Dapeng" In-Reply-To: <70b64347-2aca-4511-af78-a767d5fa8226@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On 9/30/2025 1:30 PM, Borah, Chaitanya Kumar wrote: > Hello Sean, > > Hope you are doing well. I am Chaitanya from the linux graphics team in > Intel. > > This mail is regarding a regression we are seeing in our CI runs[1] on > linux-next repository. > > Since the version next-20250919 [2], we are seeing the following regression > > ````````````````````````````````````````````````````````````````````````````````` > <4>[ 10.973827] ------------[ cut here ]------------ > <4>[ 10.973841] WARNING: arch/x86/events/core.c:3089 at > perf_get_x86_pmu_capability+0xd/0xc0, CPU#15: (udev-worker)/386 > ... > <4>[ 10.974028] Call Trace: > <4>[ 10.974030] > <4>[ 10.974033] ? kvm_init_pmu_capability+0x2b/0x190 [kvm] > <4>[ 10.974154] kvm_x86_vendor_init+0x1b0/0x1a40 [kvm] > <4>[ 10.974248] vmx_init+0xdb/0x260 [kvm_intel] > <4>[ 10.974278] ? __pfx_vt_init+0x10/0x10 [kvm_intel] > <4>[ 10.974296] vt_init+0x12/0x9d0 [kvm_intel] > <4>[ 10.974309] ? __pfx_vt_init+0x10/0x10 [kvm_intel] > <4>[ 10.974322] do_one_initcall+0x60/0x3f0 > <4>[ 10.974335] do_init_module+0x97/0x2b0 > <4>[ 10.974345] load_module+0x2d08/0x2e30 > <4>[ 10.974349] ? __kernel_read+0x158/0x2f0 > <4>[ 10.974370] ? kernel_read_file+0x2b1/0x320 > <4>[ 10.974381] init_module_from_file+0x96/0xe0 > <4>[ 10.974384] ? init_module_from_file+0x96/0xe0 > <4>[ 10.974399] idempotent_init_module+0x117/0x330 > <4>[ 10.974415] __x64_sys_finit_module+0x73/0xe0 > ... > ````````````````````````````````````````````````````````````````````````````````` > Details log can be found in [3]. > > After bisecting the tree, the following patch [4] seems to be the first > "bad" commit > > ````````````````````````````````````````````````````````````````````````````````````````````````````````` > From 51f34b1e650fc5843530266cea4341750bd1ae37 Mon Sep 17 00:00:00 2001 > > From: Sean Christopherson > > Date: Wed, 6 Aug 2025 12:56:39 -0700 > > Subject: KVM: x86/pmu: Snapshot host (i.e. perf's) reported PMU capabilities > > Take a snapshot of the unadulterated PMU capabilities provided by perf so > that KVM can compare guest vPMU capabilities against hardware capabilities > when determining whether or not to intercept PMU MSRs (and RDPMC). > ````````````````````````````````````````````````````````````````````````````````````````````````````````` > > We also verified that if we revert the patch the issue is not seen. > > Could you please check why the patch causes this regression and provide > a fix if necessary? Hi Chaitanya, I suppose you found this warning on a hybrid client platform, right? It looks the warning is triggered by the below WARN_ON_ONCE() in perf_get_x86_pmu_capability() function.   if (WARN_ON_ONCE(cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) ||         !x86_pmu_initialized()) {         memset(cap, 0, sizeof(*cap));         return;     } The below change should fix it (just building, not test it). I would run a full scope vPMU test after I come back from China national day's holiday. Thanks. diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index cebce7094de8..6d87c25226d8 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -108,8 +108,6 @@ void kvm_init_pmu_capability(struct kvm_pmu_ops *pmu_ops)         bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;         int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS; -       perf_get_x86_pmu_capability(&kvm_host_pmu); -         /*          * Hybrid PMUs don't play nice with virtualization without careful          * configuration by userspace, and KVM's APIs for reporting supported @@ -120,6 +118,8 @@ void kvm_init_pmu_capability(struct kvm_pmu_ops *pmu_ops)                 enable_pmu = false;         if (enable_pmu) { +               perf_get_x86_pmu_capability(&kvm_host_pmu); +                 /*                  * WARN if perf did NOT disable hardware PMU if the number of                  * architecturally required GP counters aren't present, i.e. if > > Thank you. > > Regards > > Chaitanya > > [1] > https://intel-gfx-ci.01.org/tree/linux-next/combined-alt.html? > [2] > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?h=next-20250919 > [3] > https://intel-gfx-ci.01.org/tree/linux-next/next-20250919/bat-arlh-2/boot0.txt > [4] > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?h=next-20250919&id=51f34b1e650fc5843530266cea4341750bd1ae37 >