From patchwork Tue May 24 17:06:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 12860384 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44634C433F5 for ; Tue, 24 May 2022 17:07:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239890AbiEXRHj (ORCPT ); Tue, 24 May 2022 13:07:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235069AbiEXRHb (ORCPT ); Tue, 24 May 2022 13:07:31 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 81CE17E1FD for ; Tue, 24 May 2022 10:07:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653412048; 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; bh=GxIUBanOlo4kCZlBLy+vq6QBMWA1M+KHEcRWloPp9vs=; b=SxYQABIff5LIPdMxMPCt3LFhcfbEHSjAtzO1fz+dnP0wlS68/FsirkGvE2EsfPRWsAYrOH WlPlHLgDTlK9Qwg+Nir+oxz5H6rEcRz95F3ea8KTh6WIDSVUXIh6o8MrHVE7XiuNbrsBvE dIoA7HvXkRFr7P8vpYg+VtnfY9fK17I= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-151-2xLvnYQCMHOtyYr0ccgPhw-1; Tue, 24 May 2022 13:06:18 -0400 X-MC-Unique: 2xLvnYQCMHOtyYr0ccgPhw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7F2692999B2D; Tue, 24 May 2022 17:06:17 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.195.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9EB7D2026D64; Tue, 24 May 2022 17:06:12 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, Jason Wang , "Michael S. Tsirkin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Parav Pandit , Zhang Min , hanand@xilinx.com, Zhu Lingshan , tanuj.kamde@amd.com, gautam.dawar@amd.com, Christophe JAILLET , Xie Yongji , dinang@xilinx.com, habetsm.xilinx@gmail.com, Eli Cohen , pabloc@xilinx.com, lvivier@redhat.com, Dan Carpenter , lulu@redhat.com, Wu Zongyong , eperezma@redhat.com, ecree.xilinx@gmail.com, Piotr.Uminski@intel.com, martinpo@xilinx.com, Stefano Garzarella , Si-Wei Liu , Longpeng , martinh@xilinx.com Subject: [PATCH v2 0/4] Implement vdpasim stop operation Date: Tue, 24 May 2022 19:06:06 +0200 Message-Id: <20220524170610.2255608-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Implement stop operation for vdpa_sim devices, so vhost-vdpa will offer that backend feature and userspace can effectively stop the device. This is a must before get virtqueue indexes (base) for live migration, since the device could modify them after userland gets them. There are individual ways to perform that action for some devices (VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no way to perform it for any vhost device (and, in particular, vhost-vdpa). After the return of ioctl with stop != 0, the device MUST finish any pending operations like in flight requests. It must also preserve all the necessary state (the virtqueue vring base plus the possible device specific states) that is required for restoring in the future. The device must not change its configuration after that point. After the return of ioctl with stop == 0, the device can continue processing buffers as long as typical conditions are met (vq is enabled, DRIVER_OK status bit is enabled, etc). In the future, we will provide features similar to VHOST_USER_GET_INFLIGHT_FD so the device can save pending operations. Comments are welcome. v2: * Replace raw _F_STOP with BIT_ULL(_F_STOP). * Fix obtaining of stop ioctl arg (it was not obtained but written). * Add stop to vdpa_sim_blk. Eugenio Pérez (4): vdpa: Add stop operation vhost-vdpa: introduce STOP backend feature bit vhost-vdpa: uAPI to stop the device vdpa_sim: Implement stop vdpa op drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++ drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 + drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 3 +++ drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++ drivers/vhost/vdpa.c | 34 +++++++++++++++++++++++++++- include/linux/vdpa.h | 6 +++++ include/uapi/linux/vhost.h | 3 +++ include/uapi/linux/vhost_types.h | 2 ++ 8 files changed, 72 insertions(+), 1 deletion(-)