From nobody Wed Feb 11 05:13:50 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=1768218424; cv=none; d=zohomail.com; s=zohoarc; b=eKpOVCkMyJ6LDsQNys2otBlzAx1vgiSFqA+qZFfIf0XqZbw3OyxQ7f8sWXHF4UlXEQ4KRV+Yfkn6SUMWnMnFLl9tU+gMfxhPzt73DsJwWJ3U/m9dh2ldpUbhlTHc0XLaw+sghLHyTrh4+wGmew9XOcL74t575B30UZ8pijqxkkE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1768218424; 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=nfZPQcjXT6vONkk0bybRsacv/92h7tVCdrsunkiRKl4=; b=ltEZPnVjdqDpam4O3xLNuyGSD4flfUj3CaHVe1oQvxdm4TeyuoLdY3q5sIjn2kRfJTQ87vSChgCk5Xm5CFEwvsPkRQcRc/gMN07Yg1HjOLo/ko888q3zNCgmmZs1DtH7s1HWDm2dFRqvBrImZnT1VCPL/ZJizCtEIWplc6ymC24= 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 1768218424319448.7618231562958; Mon, 12 Jan 2026 03:47:04 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vfGMu-0007WV-SA; Mon, 12 Jan 2026 06:45:56 -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 1vfGMb-0007O4-TC; Mon, 12 Jan 2026 06:45:41 -0500 Received: from forwardcorp1b.mail.yandex.net ([2a02:6b8:c02:900:1:45:d181:df01]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vfGMZ-0004nr-ST; Mon, 12 Jan 2026 06:45:37 -0500 Received: from mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net (mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net [IPv6:2a02:6b8:c24:fa2:0:640:41ee:0]) by forwardcorp1b.mail.yandex.net (Yandex) with ESMTPS id 028778080B; Mon, 12 Jan 2026 14:45:34 +0300 (MSK) Received: from dtalexundeer-nx.yandex.net (unknown [2a02:6bf:803e:400:6fcf:dbb2:9b0:d80b]) by mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id 6jQQPI5AAW20-faBhtnOa; Mon, 12 Jan 2026 14:45:33 +0300 Precedence: bulk X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1768218333; bh=nfZPQcjXT6vONkk0bybRsacv/92h7tVCdrsunkiRKl4=; h=Message-Id:Date:In-Reply-To:Cc:Subject:References:To:From; b=njslUpcr5Tox2tXKC5kqGo1BBXrhatqk6xfyUxQwzzB8SBNZnXlCZmzAtO1MPliES 3nb9DU0X02HpXpIQuqwJlbFXyKq6mlHtLw7i2W+NszkugNIksy+AVL+TzyMYPhkgH3 Dv9nIlVtZhYeMPyPlYURs7hl9uaZZrY2dFmges34= Authentication-Results: mail-nwsmtp-smtp-corp-main-34.sas.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 v5 5/5] vhost-user-blk: support inter-host inflight migration Date: Mon, 12 Jan 2026 16:45:03 +0500 Message-Id: <20260112114503.1174330-6-dtalexundeer@yandex-team.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260112114503.1174330-1-dtalexundeer@yandex-team.ru> References: <20260112114503.1174330-1-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=2a02:6b8:c02:900:1:45:d181:df01; envelope-from=dtalexundeer@yandex-team.ru; helo=forwardcorp1b.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, 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: qemu development 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: 1768218426595158500 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, with feature flag the vhost-user back-end can immediately stop vrings, so all in-flight requests will be migrated to another host. Signed-off-by: Alexandr Moshkov --- hw/block/vhost-user-blk.c | 28 ++++++++++++++++++++++++++++ include/hw/virtio/vhost-user-blk.h | 1 + 2 files changed, 29 insertions(+) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index a8fd90480a..5e44f6253c 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -656,6 +656,28 @@ 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; + + bool inflight_drain =3D vhost_dev_has_feature(&s->dev, + VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT); + + return s->inflight_migration && + inflight_drain && + !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); @@ -678,6 +700,10 @@ 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) @@ -751,6 +777,8 @@ 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