From nobody Sun Feb 8 11:51:46 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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 151878752782957.13251511192868; Fri, 16 Feb 2018 05:25:27 -0800 (PST) Received: from localhost ([::1]:48216 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1emg0y-000845-NY for importer@patchew.org; Fri, 16 Feb 2018 08:25:24 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51702) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1emfsT-0001E8-DL for qemu-devel@nongnu.org; Fri, 16 Feb 2018 08:16:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1emfsR-0005d2-VU for qemu-devel@nongnu.org; Fri, 16 Feb 2018 08:16:37 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34846 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1emfsR-0005cc-Q4 for qemu-devel@nongnu.org; Fri, 16 Feb 2018 08:16:35 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 71F58407519B for ; Fri, 16 Feb 2018 13:16:35 +0000 (UTC) Received: from dgilbert-t530.redhat.com (unknown [10.36.118.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 43E0B213AEE2; Fri, 16 Feb 2018 13:16:34 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, maxime.coquelin@redhat.com, marcandre.lureau@redhat.com, peterx@redhat.com, imammedo@redhat.com, mst@redhat.com Date: Fri, 16 Feb 2018 13:16:01 +0000 Message-Id: <20180216131625.9639-6-dgilbert@redhat.com> In-Reply-To: <20180216131625.9639-1-dgilbert@redhat.com> References: <20180216131625.9639-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 16 Feb 2018 13:16:35 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 16 Feb 2018 13:16:35 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dgilbert@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v3 05/29] 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: aarcange@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 Reviewed-by: Peter Xu --- contrib/libvhost-user/libvhost-user.h | 1 + docs/interop/vhost-user.txt | 10 +++++++++ hw/virtio/vhost-user.c | 41 +++++++++++++++++++++++++++++++= +++- 3 files changed, 51 insertions(+), 1 deletion(-) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/= libvhost-user.h index 18f95f65d7..a0dcc97c73 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -48,6 +48,7 @@ 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, =20 VHOST_USER_PROTOCOL_F_MAX }; diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index 9fcf48d611..e95cd82677 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -290,6 +290,15 @@ 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. + Memory access ------------- =20 @@ -368,6 +377,7 @@ 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 6eb97980ad..d60f89cc16 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 @@ -39,7 +41,7 @@ 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 @@ -148,8 +150,10 @@ 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) @@ -775,6 +779,33 @@ 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; @@ -786,6 +817,7 @@ 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); @@ -842,6 +874,9 @@ 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 @@ -852,6 +887,10 @@ 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); + u->postcopy_notifier.notify =3D NULL; + } if (u->slave_fd >=3D 0) { qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL); close(u->slave_fd); --=20 2.14.3