From patchwork Tue Feb 9 15:37:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 12078495 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C41DC433E0 for ; Tue, 9 Feb 2021 15:49:48 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0A97C64E05 for ; Tue, 9 Feb 2021 15:49:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A97C64E05 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38370 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9VGs-0003fe-Sf for qemu-devel@archiver.kernel.org; Tue, 09 Feb 2021 10:49:46 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40768) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9V6J-0003kj-PM for qemu-devel@nongnu.org; Tue, 09 Feb 2021 10:38:51 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25529) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9V6F-0008Kr-S8 for qemu-devel@nongnu.org; Tue, 09 Feb 2021 10:38:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612885125; 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: in-reply-to:in-reply-to:references:references; bh=gpifSbnjYPCdwCNzWIyzHdufTbFFRRTIJ6we5pSJcKY=; b=JdT5dXnJ1a+uV7llNmTxifklaXovoas3UiGx+rXTQnupOoobB6RZH7EbQtHvuPdGwAHh7N Rs+dKxhuOaBE1oi2qBqkizKxpA4XJmislneJnSNHvR7SVoHEtPeKuOYIdP3lrXoKyomrHk imQif8q4DEhmnusLjYvjHbxaxyyaet4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-237-qwUDRcXxPt6kt1KNItsPIw-1; Tue, 09 Feb 2021 10:38:41 -0500 X-MC-Unique: qwUDRcXxPt6kt1KNItsPIw-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id E48A080197B; Tue, 9 Feb 2021 15:38:39 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-113-210.ams2.redhat.com [10.36.113.210]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8592760861; Tue, 9 Feb 2021 15:38:36 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC v2 6/7] vhost: Route guest->host notification through shadow virtqueue Date: Tue, 9 Feb 2021 16:37:56 +0100 Message-Id: <20210209153757.1653598-7-eperezma@redhat.com> In-Reply-To: <20210209153757.1653598-1-eperezma@redhat.com> References: <20210209153757.1653598-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eperezma@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Parav Pandit , "Michael S. Tsirkin" , Jason Wang , Juan Quintela , Markus Armbruster , virtualization@lists.linux-foundation.org, Harpreet Singh Anand , Xiao W Wang , Stefan Hajnoczi , Eli Cohen , Rob Miller , Michael Lilja , Jim Harford , Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Shadow virtqueue notifications forwarding is disabled when vhost_dev stops. Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.h | 7 ++ include/hw/virtio/vhost.h | 4 + hw/virtio/vhost-shadow-virtqueue.c | 97 ++++++++++++++++++- hw/virtio/vhost.c | 148 ++++++++++++++++++++++++++++- 4 files changed, 253 insertions(+), 3 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index 6cc18d6acb..c45035c4b7 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -17,6 +17,13 @@ typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; +bool vhost_shadow_vq_start_rcu(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq); +void vhost_shadow_vq_stop_rcu(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq); + VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx); void vhost_shadow_vq_free(VhostShadowVirtqueue *vq); diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index ac963bf23d..884818b109 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -55,6 +55,8 @@ struct vhost_iommu { QLIST_ENTRY(vhost_iommu) iommu_next; }; +typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; + typedef struct VhostDevConfigOps { /* Vhost device config space changed callback */ @@ -83,7 +85,9 @@ struct vhost_dev { uint64_t backend_cap; bool started; bool log_enabled; + bool sw_lm_enabled; uint64_t log_size; + VhostShadowVirtqueue **shadow_vqs; Error *migration_blocker; const VhostOps *vhost_ops; void *opaque; diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index b5d2645ae0..01f282d434 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -8,9 +8,12 @@ */ #include "hw/virtio/vhost-shadow-virtqueue.h" +#include "hw/virtio/vhost.h" + +#include "standard-headers/linux/vhost_types.h" #include "qemu/error-report.h" -#include "qemu/event_notifier.h" +#include "qemu/main-loop.h" /* Shadow virtqueue to relay notifications */ typedef struct VhostShadowVirtqueue { @@ -18,8 +21,95 @@ typedef struct VhostShadowVirtqueue { EventNotifier kick_notifier; /* Shadow call notifier, sent to vhost */ EventNotifier call_notifier; + + /* Borrowed virtqueue's guest to host notifier. */ + EventNotifier host_notifier; + + /* Virtio queue shadowing */ + VirtQueue *vq; } VhostShadowVirtqueue; +/* Forward guest notifications */ +static void vhost_handle_guest_kick(EventNotifier *n) +{ + VhostShadowVirtqueue *svq = container_of(n, VhostShadowVirtqueue, + host_notifier); + + if (event_notifier_test_and_clear(n)) { + event_notifier_set(&svq->kick_notifier); + } +} + +/* + * Start shadow virtqueue operation. + * @dev vhost device + * @hidx vhost virtqueue index + * @svq Shadow Virtqueue + * + * Run in RCU context + */ +bool vhost_shadow_vq_start_rcu(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq) +{ + EventNotifier *vq_host_notifier = virtio_queue_get_host_notifier(svq->vq); + struct vhost_vring_file kick_file = { + .index = idx, + .fd = event_notifier_get_fd(&svq->kick_notifier), + }; + int r; + + /* Check that notifications are still going directly to vhost dev */ + assert(virtio_queue_host_notifier_status(svq->vq)); + + event_notifier_init_fd(&svq->host_notifier, + event_notifier_get_fd(vq_host_notifier)); + event_notifier_set_handler(&svq->host_notifier, vhost_handle_guest_kick); + + r = dev->vhost_ops->vhost_set_vring_kick(dev, &kick_file); + if (unlikely(r != 0)) { + error_report("Couldn't set kick fd: %s", strerror(errno)); + goto err_set_vring_kick; + } + + /* Check for pending notifications from the guest */ + vhost_handle_guest_kick(&svq->host_notifier); + + return true; + +err_set_vring_kick: + event_notifier_set_handler(&svq->host_notifier, NULL); + + return false; +} + +/* + * Stop shadow virtqueue operation. + * @dev vhost device + * @idx vhost queue index + * @svq Shadow Virtqueue + * + * Run in RCU context + */ +void vhost_shadow_vq_stop_rcu(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq) +{ + EventNotifier *vq_host_notifier = virtio_queue_get_host_notifier(svq->vq); + struct vhost_vring_file kick_file = { + .index = idx, + .fd = event_notifier_get_fd(vq_host_notifier), + }; + int r; + + /* Restore vhost kick */ + r = dev->vhost_ops->vhost_set_vring_kick(dev, &kick_file); + /* Cannot do a lot of things */ + assert(r == 0); + + event_notifier_set_handler(&svq->host_notifier, NULL); +} + /* * Creates vhost shadow virtqueue, and instruct vhost device to use the shadow * methods and file descriptors. @@ -27,8 +117,11 @@ typedef struct VhostShadowVirtqueue { VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx) { g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1); + int vq_idx = dev->vq_index + idx; int r; + svq->vq = virtio_get_queue(dev->vdev, vq_idx); + r = event_notifier_init(&svq->kick_notifier, 0); if (r != 0) { error_report("Couldn't create kick event notifier: %s", @@ -43,7 +136,7 @@ VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx) goto err_init_call_notifier; } - return svq; + return g_steal_pointer(&svq); err_init_call_notifier: event_notifier_cleanup(&svq->kick_notifier); diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 8fbf14385e..9d4728e545 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -25,6 +25,7 @@ #include "exec/address-spaces.h" #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" +#include "hw/virtio/vhost-shadow-virtqueue.h" #include "migration/blocker.h" #include "migration/qemu-file-types.h" #include "sysemu/dma.h" @@ -937,6 +938,84 @@ static void vhost_log_global_stop(MemoryListener *listener) } } +static int vhost_sw_live_migration_stop(struct vhost_dev *dev) +{ + int idx; + + WITH_RCU_READ_LOCK_GUARD() { + dev->sw_lm_enabled = false; + + for (idx = 0; idx < dev->nvqs; ++idx) { + vhost_shadow_vq_stop_rcu(dev, idx, dev->shadow_vqs[idx]); + } + } + + for (idx = 0; idx < dev->nvqs; ++idx) { + vhost_shadow_vq_free(dev->shadow_vqs[idx]); + } + + g_free(dev->shadow_vqs); + dev->shadow_vqs = NULL; + return 0; +} + +static int vhost_sw_live_migration_start(struct vhost_dev *dev) +{ + int idx; + + dev->shadow_vqs = g_new0(VhostShadowVirtqueue *, dev->nvqs); + for (idx = 0; idx < dev->nvqs; ++idx) { + dev->shadow_vqs[idx] = vhost_shadow_vq_new(dev, idx); + if (unlikely(dev->shadow_vqs[idx] == NULL)) { + goto err; + } + } + + WITH_RCU_READ_LOCK_GUARD() { + for (idx = 0; idx < dev->nvqs; ++idx) { + bool ok = vhost_shadow_vq_start_rcu(dev, idx, + dev->shadow_vqs[idx]); + + if (!ok) { + int stop_idx = idx; + + while (--stop_idx >= 0) { + vhost_shadow_vq_stop_rcu(dev, idx, + dev->shadow_vqs[stop_idx]); + } + + goto err; + } + } + } + + dev->sw_lm_enabled = true; + return 0; + +err: + for (; idx >= 0; --idx) { + vhost_shadow_vq_free(dev->shadow_vqs[idx]); + } + g_free(dev->shadow_vqs[idx]); + + return -1; +} + +static int vhost_sw_live_migration_enable(struct vhost_dev *dev, + bool enable_lm) +{ + int r; + + if (enable_lm == dev->sw_lm_enabled) { + return 0; + } + + r = enable_lm ? vhost_sw_live_migration_start(dev) + : vhost_sw_live_migration_stop(dev); + + return r; +} + static void vhost_log_start(MemoryListener *listener, MemoryRegionSection *section, int old, int new) @@ -1381,6 +1460,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, hdev->log = NULL; hdev->log_size = 0; hdev->log_enabled = false; + hdev->sw_lm_enabled = false; hdev->started = false; memory_listener_register(&hdev->memory_listener, &address_space_memory); QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); @@ -1486,6 +1566,10 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); int i, r; + if (hdev->sw_lm_enabled) { + vhost_sw_live_migration_enable(hdev, false); + } + for (i = 0; i < hdev->nvqs; ++i) { r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, false); @@ -1808,6 +1892,11 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) hdev->vhost_ops->vhost_dev_start(hdev, false); } for (i = 0; i < hdev->nvqs; ++i) { + if (hdev->sw_lm_enabled) { + vhost_shadow_vq_stop_rcu(hdev, i, hdev->shadow_vqs[i]); + vhost_shadow_vq_free(hdev->shadow_vqs[i]); + } + vhost_virtqueue_stop(hdev, vdev, hdev->vqs + i, @@ -1821,6 +1910,8 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) memory_listener_unregister(&hdev->iommu_listener); } vhost_log_put(hdev, true); + g_free(hdev->shadow_vqs); + hdev->sw_lm_enabled = false; hdev->started = false; hdev->vdev = NULL; } @@ -1837,5 +1928,60 @@ int vhost_net_set_backend(struct vhost_dev *hdev, void qmp_x_vhost_enable_shadow_vq(const char *name, bool enable, Error **errp) { - error_setg(errp, "Shadow virtqueue still not implemented"); + struct vhost_dev *hdev, *hdev_err; + VirtIODevice *vdev; + const char *err_cause = NULL; + int r; + ErrorClass err_class = ERROR_CLASS_GENERIC_ERROR; + + QLIST_FOREACH(hdev, &vhost_devices, entry) { + if (hdev->vdev && 0 == strcmp(hdev->vdev->name, name)) { + vdev = hdev->vdev; + break; + } + } + + if (!hdev) { + err_class = ERROR_CLASS_DEVICE_NOT_FOUND; + err_cause = "Device not found"; + goto not_found_err; + } + + for ( ; hdev; hdev = QLIST_NEXT(hdev, entry)) { + if (vdev != hdev->vdev) { + continue; + } + + if (!hdev->started) { + err_cause = "Device is not started"; + goto err; + } + + r = vhost_sw_live_migration_enable(hdev, enable); + if (unlikely(r)) { + err_cause = "Error enabling (see monitor)"; + goto err; + } + } + + return; + +err: + QLIST_FOREACH(hdev_err, &vhost_devices, entry) { + if (hdev_err == hdev) { + break; + } + + if (vdev != hdev->vdev) { + continue; + } + + vhost_sw_live_migration_enable(hdev, !enable); + } + +not_found_err: + if (err_cause) { + error_set(errp, err_class, + "Can't enable shadow vq on %s: %s", name, err_cause); + } }