From patchwork Fri Sep 15 10:25:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 13386841 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C6C23EE6456 for ; Fri, 15 Sep 2023 10:27:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qh61i-000760-Pj; Fri, 15 Sep 2023 06:26:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qh61C-0006cJ-5b for qemu-devel@nongnu.org; Fri, 15 Sep 2023 06:25:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qh614-0002id-Ct for qemu-devel@nongnu.org; Fri, 15 Sep 2023 06:25:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694773534; 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=UXWTN0SMvlftGADeqHk3ebQc7m49EZ0/NUqBmnDdJ9A=; b=cSpWXP0QSTSeZkpN/QKeBKxYE22FqVsDshiU5qUt2bOV/T48mTW25IkhyGNZjVY+4d4ae7 sESUuocYJTURQP0l2fpvkZTnc6KjiLomy03TnItcdqzocVXzj5A+ig2PBqtX1VFQCp/TsL OW/DyMvcBYw6Fixgi34hu2cwtb8XkPU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-638-v9KZhuIdPZ6L81_7C1b23A-1; Fri, 15 Sep 2023 06:25:33 -0400 X-MC-Unique: v9KZhuIdPZ6L81_7C1b23A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F24A48039D1 for ; Fri, 15 Sep 2023 10:25:32 +0000 (UTC) Received: from localhost (unknown [10.39.194.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 954B61004145; Fri, 15 Sep 2023 10:25:32 +0000 (UTC) From: Hanna Czenczek To: qemu-devel@nongnu.org, virtio-fs@redhat.com Cc: Hanna Czenczek , Stefan Hajnoczi , "Michael S . Tsirkin" , =?utf-8?q?Eugenio_P=C3=A9rez?= , German Maglione Subject: [PATCH v3 0/5] vhost-user: Back-end state migration Date: Fri, 15 Sep 2023 12:25:25 +0200 Message-ID: <20230915102531.55894-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org RFC: https://lists.nongnu.org/archive/html/qemu-devel/2023-03/msg04263.html v1: https://lists.nongnu.org/archive/html/qemu-devel/2023-04/msg01575.html v2: https://lists.nongnu.org/archive/html/qemu-devel/2023-07/msg02604.html Hi, I’ve decided not to work on vhost-user SUSPEND/RESUME for now – it is not technically required for virtio-fs migration, which is the actual priority for me now. While we do want to have SUSPEND/RESUME at some point, the only practically existing reason for it is to be able to implement vhost-level resetting in virtiofsd, but that is not related to migration. So one of the changes in v3 is that it no longer depends on the vhost-user SUSPEND/RESUME series, and describes the migration protocol without the device being suspended at any point, but merely that the vrings are stopped. Other changes include: - Patch 1: - Rephrased a lot - Added a description for the VHOST_USER_SET_DEVICE_STATE_FD parameters - Renamed VHOST_USER_PROTOCOL_F_MIGRATORY_STATE to VHOST_USER_PROTOCOL_F_DEVICE_STATE - enum variants changed in value due to dropping the SUSPEND/RESUME dependency - Patch 2: - Pulled in, was a stand-alone patch before - Dropped a sentence about ring state before feature negotiations, as the rings are not to be used during that period anyway - Bit of rephrasing - Patch 3: - Renamed “migratory state” to “device state” - enum variants changed in value due to dropping the SUSPEND/RESUME dependency - Patch 4: - Changed `f` to @f (referencing parameter “f”) in comments - Use g_autofree for the transfer buffer - Note SUSPEND state as a future feature, not currently existing - Wrap read() and write() in RETRY_ON_EINTR() - Patch 5: - Renamed “migratory state” to “device state” - (kept R-b still) Hanna Czenczek (5): vhost-user.rst: Migrating back-end-internal state vhost-user.rst: Clarify enabling/disabling vrings vhost-user: Interface for migration state transfer vhost: Add high-level state save/load functions vhost-user-fs: Implement internal migration docs/interop/vhost-user.rst | 188 ++++++++++++++++++++++- include/hw/virtio/vhost-backend.h | 24 +++ include/hw/virtio/vhost.h | 114 ++++++++++++++ hw/virtio/vhost-user-fs.c | 101 ++++++++++++- hw/virtio/vhost-user.c | 148 ++++++++++++++++++ hw/virtio/vhost.c | 241 ++++++++++++++++++++++++++++++ 6 files changed, 810 insertions(+), 6 deletions(-)