From patchwork Thu Oct 14 09:57:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenguo Yao X-Patchwork-Id: 12558183 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E86EC433EF for ; Thu, 14 Oct 2021 09:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3F18610CC for ; Thu, 14 Oct 2021 09:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229691AbhJNKAZ (ORCPT ); Thu, 14 Oct 2021 06:00:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbhJNKAY (ORCPT ); Thu, 14 Oct 2021 06:00:24 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D2C7C061570; Thu, 14 Oct 2021 02:58:19 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id qe4-20020a17090b4f8400b0019f663cfcd1so6529945pjb.1; Thu, 14 Oct 2021 02:58:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=G4rIb7beJwQqUdF+ZBNJoTZ2AvHg1kCA9YpDdPt+250=; b=qTgsgp7JXouqeXF5dWuhL4S6rIr8gnsnjU2RvvoTCZkUazqASzivyt7xhwJ4pYdtUI gDU+sCGxn4po6o6D73N6VgbqNDpy+ZIVcz8Yf8ODdVzLrznEqHzDWdxiwWOaPvVVB4hz ZjyYLcGuxVqbAl1XJ5kOHADIJYtpf1yHRbwjd6/0PESNIDyU6qykUd6TIMsh2IYATrDW f8nsZCGvms3GhnZERoa3vaydWepnqU3ryonss8DNWa9LXxa5VqMTLBtjOUxbUyAiVgEj OHodqrpBORUqkMJHgXupRfZHazA6ggCpVM9Chwrt1rEXl1U+q6V5aDPWXzoG/GAwCLf5 j0vg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=G4rIb7beJwQqUdF+ZBNJoTZ2AvHg1kCA9YpDdPt+250=; b=BYe9eL215n9443xxgu9XE6lnEVKt6m3SC6JsOz+nxC5pnbheJUA/CZBNjPZXJ233Q8 GRUEpNf79+YdYPSCU8Kp/jjdLWXNi/Nshaxts/J4g282XmjEomfciEsrWQuJW7s7t+B4 +QiCzlv4Nf/reYw/ihQF1J1frDHdDIrqn/GGQdB+lTufS23bHTQUrO9P18+YjJXyrxvK Q9Rk3NseymK5FBDYwB6mRIs2mPQON1dYLq9KNFNxv5JMhur2vsDUdoFURuHfO6zxQGHx bC3nj+S8s5aLRBOEK37yt/Wzoa4kO8NUd4DjYV/6EwzrVN4Mu0AujTtVbQ3AkVsy7w9X cSCw== X-Gm-Message-State: AOAM533l9JKhZ97wiYP6FXzgde9dHnZf4bA6b6T+MOrXGT67Qvc99dVB kdokLXM0aW6y20Eg09t5d6XJ8O2X+cFu3g== X-Google-Smtp-Source: ABdhPJybauUsRb6kcRpIweDhwUczxKkSy9GOsnk8QIcNBgG0KtwOGGPIusMCSU+GGv22Q6g7y+LJIA== X-Received: by 2002:a17:90a:f013:: with SMTP id bt19mr17067122pjb.82.1634205499115; Thu, 14 Oct 2021 02:58:19 -0700 (PDT) Received: from localhost.localdomain (5e.8a.38a9.ip4.static.sl-reverse.com. [169.56.138.94]) by smtp.gmail.com with ESMTPSA id k127sm2080664pfd.1.2021.10.14.02.58.16 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Oct 2021 02:58:18 -0700 (PDT) From: Zhenguo Yao To: bhelgaas@google.com, alex.williamson@redhat.com Cc: cohuck@redhat.com, jgg@ziepe.ca, mgurtovoy@nvidia.com, yishaih@nvidia.com, kvm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, yaozhenguo@jd.com, Zhenguo Yao Subject: [PATCH v1 0/2] Add ablility of VFIO driver to ignore reset when device don't need it Date: Thu, 14 Oct 2021 17:57:46 +0800 Message-Id: <20211014095748.84604-1-yaozhenguo1@gmail.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org In some scenarios, vfio device can't do any reset in initialization process. For example: Nvswitch and GPU A100 working in Shared NVSwitch Virtualization Model. In such mode, there are two type VMs: service VM and Guest VM. The GPU devices are initialized in the following steps: 1. Service VM boot up. GPUs and Nvswitchs are passthrough to service VM. Nvidia driver and manager software will do some settings in service VM. 2. The selected GPUs are unpluged from service VM. 3. Guest VM boots up with the selected GPUs passthrough. The selected GPUs can't do any reset in step3, or they will be initialized failed in Guest VM. This patchset add a PCI sysfs interface:ignore_reset which drivers can use it to control whether to do PCI reset or not. For example: In Shared NVSwitch Virtualization Model. Hypervisor can disable PCI reset by setting ignore_reset to 1 before Gust VM booting up. Zhenguo Yao (2): PCI: Add ignore_reset sysfs interface to control whether do device reset in PCI drivers vfio-pci: Don't do device reset when ignore_reset is setting drivers/pci/pci-sysfs.c | 25 +++++++++++++++++ drivers/vfio/pci/vfio_pci_core.c | 48 ++++++++++++++++++++------------ include/linux/pci.h | 1 + 3 files changed, 56 insertions(+), 18 deletions(-)