From nobody Thu Jan 8 15:11:22 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=yandex-team.ru ARC-Seal: i=1; a=rsa-sha256; t=1767003784; cv=none; d=zohomail.com; s=zohoarc; b=GMnTQS6RYc17Lz/KD+ZS9mJndWVwYgBIukj4pbKBma++HGNgXaig/P8vio4T1JoYQENv+VlOngbwPN/vU6qaPTHcYIv7it0vWuLwYDJhvahOmRS8NFHvDBOJR/5+wzyhQ6njo8q6tnZdP3/mof51f+mrd9QIwjq3nEc7XiKX+7I= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1767003784; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=N2XWNyCs9t0bsqwkHVkqoL+40YD8szXAylBG6g1naCw=; b=JNdwemK2CSu9XSWTYklUZDYz+ZG1u4zKlCFRDMdYoRaocOViXmn3Ta2hGWJ30EO4eZUUjsmnM+I2bKSkJPW/eZ6DbNbpedADlqWV/+Nf5KltMqY7Wahjy+ykblvLjb8HNlBAv9DtzuxkuUw78zGG3X8+lVbzTbaVIESRBbT0xt0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1767003784676266.86726280637413; Mon, 29 Dec 2025 02:23:04 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vaAOw-0001NC-3j; Mon, 29 Dec 2025 05:22:58 -0500 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 1vaAOi-0000wU-To; Mon, 29 Dec 2025 05:22:47 -0500 Received: from forwardcorp1a.mail.yandex.net ([178.154.239.72]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vaAOh-0005T6-8A; Mon, 29 Dec 2025 05:22:44 -0500 Received: from mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net (mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net [IPv6:2a02:6b8:c2d:7394:0:640:5a8a:0]) by forwardcorp1a.mail.yandex.net (Yandex) with ESMTPS id 88BE7C0162; Mon, 29 Dec 2025 13:22:41 +0300 (MSK) Received: from dtalexundeer-nx.yandex-team.ru (unknown [2a02:6bf:8080:b4e::1:2a]) by mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id HLeDGC1Ck0U0-qNs34U8N; Mon, 29 Dec 2025 13:22:40 +0300 Precedence: bulk X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1767003760; bh=N2XWNyCs9t0bsqwkHVkqoL+40YD8szXAylBG6g1naCw=; h=Message-Id:Date:In-Reply-To:Cc:Subject:References:To:From; b=oB1em2Ox4OueS40aRH7x1OxNHAO4w/C6j/++W/raIrnbVh/+4BQVOSIkCSwyIe4vv sxPJFGGxqygevIQXbQmOGgF1T6JWKgvU/EwY7lbqBIbxMnqjAXUa+EzXI1wheWcKl1 nM+ZQkQZ5noH4LWsYopsZl3oaFhXN24WVQlcahlI= Authentication-Results: mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: Alexandr Moshkov To: qemu-devel@nongnu.org Cc: "Gonglei (Arei)" , Zhenwei Pi , "Michael S. Tsirkin" , Stefano Garzarella , Raphael Norwitz , Kevin Wolf , Hanna Reitz , Jason Wang , Paolo Bonzini , Fam Zheng , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Stefan Hajnoczi , mzamazal@redhat.com, Peter Xu , Fabiano Rosas , qemu-block@nongnu.org, virtio-fs@lists.linux.dev, "yc-core@yandex-team.ru" , Eric Blake , Markus Armbruster , Alexandr Moshkov Subject: [PATCH v4 5/5] vhost-user-blk: support inter-host inflight migration Date: Mon, 29 Dec 2025 15:21:14 +0500 Message-Id: <20251229102107.1291790-6-dtalexundeer@yandex-team.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251229102107.1291790-1-dtalexundeer@yandex-team.ru> References: <20251229102107.1291790-1-dtalexundeer@yandex-team.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=178.154.239.72; envelope-from=dtalexundeer@yandex-team.ru; helo=forwardcorp1a.mail.yandex.net 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_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @yandex-team.ru) X-ZM-MESSAGEID: 1767003786616158500 Content-Type: text/plain; charset="utf-8" During inter-host migration, waiting for disk requests to be drained in the vhost-user backend can incur significant downtime. This can be avoided if QEMU migrates the inflight region in vhost-user-blk. Thus, during the qemu migration, the vhost-user backend can cancel all inflight requests and then, after migration, they will be executed on another host. In vhost_user_blk_stop() on incoming inter-host migration make should_drain =3D true, so after GET_VRING_BASE message all in-flight requests will be migrated to other vm Signed-off-by: Alexandr Moshkov --- hw/block/vhost-user-blk.c | 25 +++++++++++++++++++++++++ include/hw/virtio/vhost-user-blk.h | 1 + 2 files changed, 26 insertions(+) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 56d55c18c8..c537e7ef9b 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -242,6 +242,7 @@ static int vhost_user_blk_stop(VirtIODevice *vdev) =20 force_stop =3D s->skip_get_vring_base_on_force_shutdown && qemu_force_shutdown_requested(); + should_drain =3D !s->inflight_migration; =20 s->dev.backend_transfer =3D s->dev.backend_transfer || (runstate_check(RUN_STATE_FINISH_MIGRATE) && @@ -657,6 +658,24 @@ static struct vhost_dev *vhost_user_blk_get_vhost(Virt= IODevice *vdev) return &s->dev; } =20 +static bool vhost_user_blk_inflight_needed(void *opaque) +{ + struct VHostUserBlk *s =3D opaque; + + return s->inflight_migration && + !migrate_local_vhost_user_blk(); +} + +static const VMStateDescription vmstate_vhost_user_blk_inflight =3D { + .name =3D "vhost-user-blk/inflight", + .version_id =3D 1, + .needed =3D vhost_user_blk_inflight_needed, + .fields =3D (const VMStateField[]) { + VMSTATE_VHOST_INFLIGHT_REGION(inflight, VHostUserBlk), + VMSTATE_END_OF_LIST() + }, +}; + static bool vhost_user_blk_pre_incoming(void *opaque, Error **errp) { VHostUserBlk *s =3D VHOST_USER_BLK(opaque); @@ -679,6 +698,10 @@ static const VMStateDescription vmstate_vhost_user_blk= =3D { VMSTATE_VIRTIO_DEVICE, VMSTATE_END_OF_LIST() }, + .subsections =3D (const VMStateDescription * const []) { + &vmstate_vhost_user_blk_inflight, + NULL + } }; =20 static bool vhost_user_needed(void *opaque) @@ -752,6 +775,8 @@ static const Property vhost_user_blk_properties[] =3D { VIRTIO_BLK_F_WRITE_ZEROES, true), DEFINE_PROP_BOOL("skip-get-vring-base-on-force-shutdown", VHostUserBlk, skip_get_vring_base_on_force_shutdown, false), + DEFINE_PROP_BOOL("inflight-migration", VHostUserBlk, + inflight_migration, false), }; =20 static void vhost_user_blk_class_init(ObjectClass *klass, const void *data) diff --git a/include/hw/virtio/vhost-user-blk.h b/include/hw/virtio/vhost-u= ser-blk.h index b06f55fd6f..e1466e5cf6 100644 --- a/include/hw/virtio/vhost-user-blk.h +++ b/include/hw/virtio/vhost-user-blk.h @@ -52,6 +52,7 @@ struct VHostUserBlk { bool started_vu; =20 bool skip_get_vring_base_on_force_shutdown; + bool inflight_migration; =20 bool incoming_backend; }; --=20 2.34.1