From patchwork Thu May 26 12:43:34 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: 12862403 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 83E29C433F5 for ; Thu, 26 May 2022 12:43:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344137AbiEZMnw (ORCPT ); Thu, 26 May 2022 08:43:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233252AbiEZMnv (ORCPT ); Thu, 26 May 2022 08:43:51 -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 B0B5F6CAB9 for ; Thu, 26 May 2022 05:43:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653569029; 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=hVZ34liVW5jS6yomiCvu033kCaJOcsPJqRRhNkEoRM0=; b=c2y2CzhHhEQohQb128mULa9h7Kr5G23xvtCDCr2imsux7YPyKD9/soQTzO4ORH0giJZgFm json9Wo/0UeZEtlE3XwJGRP4W906uccy2OkJK9zsKeiVB9jb9QT4QYpl1421DjPbfNeuiW L269u5uZ9GmHZG/jGASzg3AIHXBTqfw= 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-399-Zu8-CG4INu-KrkxgKoMtbQ-1; Thu, 26 May 2022 08:43:46 -0400 X-MC-Unique: Zu8-CG4INu-KrkxgKoMtbQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 189F53C1902B; Thu, 26 May 2022 12:43:45 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.194.139]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5B8B440CF8EA; Thu, 26 May 2022 12:43:40 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: "Michael S. Tsirkin" , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jason Wang , netdev@vger.kernel.org Cc: martinh@xilinx.com, Stefano Garzarella , martinpo@xilinx.com, lvivier@redhat.com, pabloc@xilinx.com, Parav Pandit , Eli Cohen , Dan Carpenter , Xie Yongji , Christophe JAILLET , Zhang Min , Wu Zongyong , lulu@redhat.com, Zhu Lingshan , Piotr.Uminski@intel.com, Si-Wei Liu , ecree.xilinx@gmail.com, gautam.dawar@amd.com, habetsm.xilinx@gmail.com, tanuj.kamde@amd.com, hanand@xilinx.com, dinang@xilinx.com, Longpeng Subject: [PATCH v4 0/4] Implement vdpasim stop operation Date: Thu, 26 May 2022 14:43:34 +0200 Message-Id: <20220526124338.36247-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 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. v4: * Replace VHOST_STOP to VHOST_VDPA_STOP in vhost ioctl switch case too. v3: * s/VHOST_STOP/VHOST_VDPA_STOP/ * Add documentation and requirements of the ioctl above its definition. 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 | 14 ++++++++++++ include/uapi/linux/vhost_types.h | 2 ++ 8 files changed, 83 insertions(+), 1 deletion(-)