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=-8.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 A3D03C433E0 for ; Sun, 26 Jul 2020 13:32:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 797A0206E3 for ; Sun, 26 Jul 2020 13:32:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=hostfission.com header.i=@hostfission.com header.b="YR0m+DJD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727909AbgGZNcQ (ORCPT ); Sun, 26 Jul 2020 09:32:16 -0400 Received: from mail1.hostfission.com ([139.99.139.48]:33700 "EHLO mail1.hostfission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbgGZNcQ (ORCPT ); Sun, 26 Jul 2020 09:32:16 -0400 Received: from www1.hostfission.com (www1.hostfission.com [139.99.139.52]) by mail1.hostfission.com (Postfix) with ESMTP id A70DD41706; Sun, 26 Jul 2020 23:32:13 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hostfission.com; s=mail; t=1595770333; bh=Ei6BfRGykR1J1/uO3qHywXb/eaVBzQPhnXKWAmqXoAQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=YR0m+DJDdyVO4xMw4NCM6nfi5o4aJVXCO464gc/q61cIJroTszJs2XpadXaNUhzCu 1UXm4wafflGokMGl/Vgal52QMYbaBq8aMB65JVGmev0OuWzp3bOITolpqwNEQKBIXq GCyvdia5FeiQJna0yp5pNuqQpATtrg0KqYGv6MVk= Received: from mail.hostfission.com (www1.hostfission.com [127.0.0.1]) by www1.hostfission.com (Postfix) with ESMTP id 95F045392C; Sun, 26 Jul 2020 23:32:13 +1000 (AEST) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sun, 26 Jul 2020 23:32:13 +1000 From: Geoffrey McRae To: Alex Williamson Cc: hdanton@sina.com, tj@kernel.org, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: Re: Poor windows VFIO performance, GPU stalls (bisected) In-Reply-To: <20200726073052.284dadb2@x1.home> References: <30452714b2935b530b9c2bbf2d20854a@hostfission.com> <20200726073052.284dadb2@x1.home> Message-ID: X-Sender: geoff@hostfission.com User-Agent: Roundcube Webmail/1.3.8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-07-26 23:30, Alex Williamson wrote: > 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 Confirmed: https://github.com/torvalds/linux/commit/22540ca3d00d2990a4148a13b92209c3dc5422db > >> 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 >>