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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7A093C433DF for ; Sun, 26 Jul 2020 13:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ED87206E3 for ; Sun, 26 Jul 2020 13:31:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ApTIxpeo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727815AbgGZNbB (ORCPT ); Sun, 26 Jul 2020 09:31:01 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:20500 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726711AbgGZNbB (ORCPT ); Sun, 26 Jul 2020 09:31:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595770260; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=W/A2bM4QDQNoWhlsEvHOmFTbiGGj6Tky9OF/epfzxYU=; b=ApTIxpeoL+rkSUq8XIYADlXwt6r7hGpzoa03B7iPvD/5f1yqoPXwM7Ne0PKvESfqXtVfeR xBrn1r3yT4U9lchSc5kgwiDTKCOZLAIT839d3W6qHGXhroOv5OiKqfuzJe1Fbh1x7G9WlS kMgbqQtwwvSzIJfUG1oveDqh+W2fd/g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-214-49rHXPKhNie0iPPxSI1LUg-1; Sun, 26 Jul 2020 09:30:54 -0400 X-MC-Unique: 49rHXPKhNie0iPPxSI1LUg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8A48F1902EA0; Sun, 26 Jul 2020 13:30:53 +0000 (UTC) Received: from x1.home (ovpn-112-71.phx2.redhat.com [10.3.112.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id E02C61001281; Sun, 26 Jul 2020 13:30:52 +0000 (UTC) Date: Sun, 26 Jul 2020 07:30:52 -0600 From: Alex Williamson To: Geoffrey McRae Cc: hdanton@sina.com, tj@kernel.org, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: Re: Poor windows VFIO performance, GPU stalls (bisected) Message-ID: <20200726073052.284dadb2@x1.home> In-Reply-To: <30452714b2935b530b9c2bbf2d20854a@hostfission.com> References: <30452714b2935b530b9c2bbf2d20854a@hostfission.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 26 Jul 2020 17:49:07 +1000 Geoffrey McRae wrote: > Hi All, > > The commit 22540ca3d00d2990a4148a13b92209c3dc5422db causes a Windows KVM > guest running under QEMU with a VFIO passthrough GPU to randomly stall > when using the GPU leading to the guest assuming that the driver has > hung. Reverting this commit resolves the problem. Please double check this commit ID, I can't find it in mainline or linux-next. Thanks, Alex > The host system is configured with the following kernel arguments which > may be related: > isolcpus=0-5,24-29,6-11,30-35 rcu_nocbs=0-5,24-29,6-11,30-35 > > The system is an AMD Threadripper 2970WX on a Gigabyte x399 AORUS Gaming > 7 board. > It has two GPUs each being passed through to two separate KVM guests, > one is an AMD Radeon 7 in a Linux guest, the other is a GeForce 1080Ti > in a Windows guest. > The cores used for these two guests are isolated from the host for > performance reasons. > > Any insight as to why this is occurring would be appreciated. If you > need any more information or would like to test patches please let me > know. > > Kind Regards, > Geoffrey McRae > HostFission > > https://hostfission.com >