From nobody Sun Feb 8 17:48:05 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1503603475605568.0083618411318; Thu, 24 Aug 2017 12:37:55 -0700 (PDT) Received: from localhost ([::1]:50159 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkxww-0002Sz-9I for importer@patchew.org; Thu, 24 Aug 2017 15:37:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52145) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkxna-00025K-2O for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:28:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dkxnY-0004SW-Qf for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:28:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48928) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dkxnY-0004Ri-Ga for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:28:12 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 88F2D61462; Thu, 24 Aug 2017 19:28:11 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-165.ams2.redhat.com [10.36.117.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id A72DF17CC4; Thu, 24 Aug 2017 19:28:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 88F2D61462 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dgilbert@redhat.com From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, maxime.coquelin@redhat.com, a.perevalov@samsung.com, mst@redhat.com, marcandre.lureau@redhat.com Date: Thu, 24 Aug 2017 20:27:06 +0100 Message-Id: <20170824192730.8440-9-dgilbert@redhat.com> In-Reply-To: <20170824192730.8440-1-dgilbert@redhat.com> References: <20170824192730.8440-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 24 Aug 2017 19:28:11 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC v2 08/32] postcopy: Add vhost-user flag for postcopy and check it X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, aarcange@redhat.com, felipe@nutanix.com, peterx@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" Add a vhost feature flag for postcopy support, and use the postcopy notifier to check it before allowing postcopy. Signed-off-by: Dr. David Alan Gilbert --- contrib/libvhost-user/libvhost-user.h | 1 + docs/interop/vhost-user.txt | 10 +++++++++ hw/virtio/vhost-user.c | 40 +++++++++++++++++++++++++++++++= +++- 3 files changed, 50 insertions(+), 1 deletion(-) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/= libvhost-user.h index acd019876d..95d0d34a28 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -34,6 +34,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_MQ =3D 0, VHOST_USER_PROTOCOL_F_LOG_SHMFD =3D 1, VHOST_USER_PROTOCOL_F_RARP =3D 2, + VHOST_USER_PROTOCOL_F_PAGEFAULT =3D 7, =20 VHOST_USER_PROTOCOL_F_MAX }; diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index 954771d0d8..a279560eb0 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -273,6 +273,15 @@ Once the source has finished migration, rings will be = stopped by the source. No further update must be done before rings are restarted. =20 +In postcopy migration the slave is started before all the memory has been +received from the source host, and care must be taken to avoid accessing p= ages +that have yet to be received. The slave opens a 'userfault'-fd and regist= ers +the memory with it; this fd is then passed back over to the master. +The master services requests on the userfaultfd for pages that are accessed +and when the page is available it performs WAKE ioctl's on the userfaultfd +to wake the stalled slave. The client indicates support for this via the +VHOST_USER_PROTOCOL_F_PAGEFAULT feature. + IOMMU support ------------- =20 @@ -327,6 +336,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_MTU 4 #define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 #define VHOST_USER_PROTOCOL_F_CROSS_ENDIAN 6 +#define VHOST_USER_PROTOCOL_F_PAGEFAULT 7 =20 Master message types -------------------- diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 093675ed98..c51bbd1296 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -17,6 +17,8 @@ #include "sysemu/kvm.h" #include "qemu/error-report.h" #include "qemu/sockets.h" +#include "migration/migration.h" +#include "migration/postcopy-ram.h" =20 #include #include @@ -34,7 +36,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_NET_MTU =3D 4, VHOST_USER_PROTOCOL_F_SLAVE_REQ =3D 5, VHOST_USER_PROTOCOL_F_CROSS_ENDIAN =3D 6, - + VHOST_USER_PROTOCOL_F_PAGEFAULT =3D 7, VHOST_USER_PROTOCOL_F_MAX }; =20 @@ -123,8 +125,10 @@ static VhostUserMsg m __attribute__ ((unused)); #define VHOST_USER_VERSION (0x1) =20 struct vhost_user { + struct vhost_dev *dev; CharBackend *chr; int slave_fd; + NotifierWithReturn postcopy_notifier; }; =20 static bool ioeventfd_enabled(void) @@ -720,6 +724,33 @@ out: return ret; } =20 +static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier, + void *opaque) +{ + struct PostcopyNotifyData *pnd =3D opaque; + struct vhost_user *u =3D container_of(notifier, struct vhost_user, + postcopy_notifier); + struct vhost_dev *dev =3D u->dev; + + switch (pnd->reason) { + case POSTCOPY_NOTIFY_PROBE: + if (!virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_PAGEFAULT)) { + /* TODO: Get the device name into this error somehow */ + error_setg(pnd->errp, + "vhost-user backend not capable of postcopy"); + return -ENOENT; + } + break; + + default: + /* We ignore notifications we don't know */ + break; + } + + return 0; +} + static int vhost_user_init(struct vhost_dev *dev, void *opaque) { uint64_t features, protocol_features; @@ -731,6 +762,7 @@ static int vhost_user_init(struct vhost_dev *dev, void = *opaque) u =3D g_new0(struct vhost_user, 1); u->chr =3D opaque; u->slave_fd =3D -1; + u->dev =3D dev; dev->opaque =3D u; =20 err =3D vhost_user_get_features(dev, &features); @@ -787,6 +819,9 @@ static int vhost_user_init(struct vhost_dev *dev, void = *opaque) return err; } =20 + u->postcopy_notifier.notify =3D vhost_user_postcopy_notifier; + postcopy_add_notifier(&u->postcopy_notifier); + return 0; } =20 @@ -797,6 +832,9 @@ static int vhost_user_cleanup(struct vhost_dev *dev) assert(dev->vhost_ops->backend_type =3D=3D VHOST_BACKEND_TYPE_USER); =20 u =3D dev->opaque; + if (u->postcopy_notifier.notify) { + postcopy_remove_notifier(&u->postcopy_notifier); + } if (u->slave_fd >=3D 0) { qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL); close(u->slave_fd); --=20 2.13.5