From patchwork Mon Mar 15 19:48:34 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: 12140565 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 B518EC433DB for ; Mon, 15 Mar 2021 19:51:34 +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 1967B64DF0 for ; Mon, 15 Mar 2021 19:51:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1967B64DF0 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]:52520 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lLtFU-0007FF-LM for qemu-devel@archiver.kernel.org; Mon, 15 Mar 2021 15:51:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37666) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lLtDW-0005Rc-U9 for qemu-devel@nongnu.org; Mon, 15 Mar 2021 15:49:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20785) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lLtDM-00040s-J0 for qemu-devel@nongnu.org; Mon, 15 Mar 2021 15:49:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615837759; 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=7SOcpUXr4KJY4dwgxs4jw9yDkBbfxO7eDLVPHAfKXOo=; b=QA0MDt3C1pduRwdIYsbaMhwCu/Ms4eyTSDlR0gccnn7jZ+KpsCHbuYOVsz+XILXoUjpTD1 xErlsgUAKx2cJL9JbUa+bW5gnUKtDKinrawOAAWPWXSEZxLqNRTdFsNWjgIuUumsAyi5JA Tmt9rJ0GCEdOePthyMsjx7QIWUoMHzE= 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-253-DCqqoff8Ob6Ajf6esBBChg-1; Mon, 15 Mar 2021 15:49:17 -0400 X-MC-Unique: DCqqoff8Ob6Ajf6esBBChg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B5C5A19200CD; Mon, 15 Mar 2021 19:49:15 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-112-173.ams2.redhat.com [10.36.112.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 623BD5F9B8; Mon, 15 Mar 2021 19:49:12 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC v2 05/13] vhost: Route guest->host notification through shadow virtqueue Date: Mon, 15 Mar 2021 20:48:34 +0100 Message-Id: <20210315194842.277740-6-eperezma@redhat.com> In-Reply-To: <20210315194842.277740-1-eperezma@redhat.com> References: <20210315194842.277740-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.25, 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" , Guru Prasad , Jason Wang , Juan Quintela , Markus Armbruster , virtualization@lists.linux-foundation.org, Harpreet Singh Anand , Xiao W Wang , Eli Cohen , Stefano Garzarella , Michael Lilja , Jim Harford , Rob Miller 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, so code flow follows usual cleanup. Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.h | 7 ++ include/hw/virtio/vhost.h | 4 + hw/virtio/vhost-shadow-virtqueue.c | 113 ++++++++++++++++++++++- hw/virtio/vhost.c | 143 ++++++++++++++++++++++++++++- 4 files changed, 265 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index 6cc18d6acb..c891c6510d 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(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq); +void vhost_shadow_vq_stop(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..7ffdf9aea0 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 shadow_vqs_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 4512e5b058..3e43399e9c 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 { @@ -18,14 +21,121 @@ typedef struct VhostShadowVirtqueue { EventNotifier kick_notifier; /* Shadow call notifier, sent to vhost */ EventNotifier call_notifier; + + /* + * Borrowed virtqueue's guest to host notifier. + * To borrow it in this event notifier allows to register on the event + * loop and access the associated shadow virtqueue easily. If we use the + * VirtQueue, we don't have an easy way to retrieve it. + * + * So shadow virtqueue must not clean it, or we would lose VirtQueue one. + */ + 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 (unlikely(!event_notifier_test_and_clear(n))) { + return; + } + + event_notifier_set(&svq->kick_notifier); +} + +/* + * Restore the vhost guest to host notifier, i.e., disables svq effect. + */ +static int vhost_shadow_vq_restore_vdev_host_notifier(struct vhost_dev *dev, + unsigned vhost_index, + VhostShadowVirtqueue *svq) +{ + EventNotifier *vq_host_notifier = virtio_queue_get_host_notifier(svq->vq); + struct vhost_vring_file file = { + .index = vhost_index, + .fd = event_notifier_get_fd(vq_host_notifier), + }; + int r; + + /* Restore vhost kick */ + r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); + return r ? -errno : 0; +} + +/* + * Start shadow virtqueue operation. + * @dev vhost device + * @hidx vhost virtqueue index + * @svq Shadow Virtqueue + */ +bool vhost_shadow_vq_start(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq) +{ + EventNotifier *vq_host_notifier = virtio_queue_get_host_notifier(svq->vq); + struct vhost_vring_file 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_is_host_notifier_enabled(svq->vq)); + + /* + * event_notifier_set_handler already checks for guest's notifications if + * they arrive in the switch, so there is no need to explicitely check for + * them. + */ + 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, &file); + if (unlikely(r != 0)) { + error_report("Couldn't set kick fd: %s", strerror(errno)); + goto err_set_vring_kick; + } + + 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 + */ +void vhost_shadow_vq_stop(struct vhost_dev *dev, + unsigned idx, + VhostShadowVirtqueue *svq) +{ + int r = vhost_shadow_vq_restore_vdev_host_notifier(dev, idx, svq); + if (unlikely(r < 0)) { + error_report("Couldn't restore vq kick fd: %s", strerror(-r)); + } + + event_notifier_set_handler(&svq->host_notifier, NULL); +} + /* * Creates vhost shadow virtqueue, and instruct vhost device to use the shadow * methods and file descriptors. */ VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx) { + int vq_idx = dev->vq_index + idx; g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1); int r; @@ -43,6 +153,7 @@ VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx) goto err_init_call_notifier; } + svq->vq = virtio_get_queue(dev->vdev, vq_idx); return g_steal_pointer(&svq); err_init_call_notifier: diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 97f1bcfa42..4858a35df6 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" @@ -1219,6 +1220,74 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev, 0, virtio_queue_get_desc_size(vdev, idx)); } +static int vhost_sw_live_migration_stop(struct vhost_dev *dev) +{ + int idx; + + dev->shadow_vqs_enabled = false; + + for (idx = 0; idx < dev->nvqs; ++idx) { + vhost_shadow_vq_stop(dev, idx, dev->shadow_vqs[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, stop_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_new; + } + } + + dev->shadow_vqs_enabled = true; + for (idx = 0; idx < dev->nvqs; ++idx) { + bool ok = vhost_shadow_vq_start(dev, idx, dev->shadow_vqs[idx]); + if (unlikely(!ok)) { + goto err_start; + } + } + + return 0; + +err_start: + dev->shadow_vqs_enabled = false; + for (stop_idx = 0; stop_idx < idx; stop_idx++) { + vhost_shadow_vq_stop(dev, idx, dev->shadow_vqs[stop_idx]); + } + +err_new: + for (idx = 0; idx < dev->nvqs; ++idx) { + vhost_shadow_vq_free(dev->shadow_vqs[idx]); + } + g_free(dev->shadow_vqs); + + return -1; +} + +static int vhost_sw_live_migration_enable(struct vhost_dev *dev, + bool enable_lm) +{ + int r; + + if (enable_lm == dev->shadow_vqs_enabled) { + return 0; + } + + r = enable_lm ? vhost_sw_live_migration_start(dev) + : vhost_sw_live_migration_stop(dev); + + return r; +} + static void vhost_eventfd_add(MemoryListener *listener, MemoryRegionSection *section, bool match_data, uint64_t data, EventNotifier *e) @@ -1381,6 +1450,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, hdev->log = NULL; hdev->log_size = 0; hdev->log_enabled = false; + hdev->shadow_vqs_enabled = false; hdev->started = false; memory_listener_register(&hdev->memory_listener, &address_space_memory); QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); @@ -1484,6 +1554,10 @@ 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->shadow_vqs_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); @@ -1798,6 +1872,7 @@ fail_features: void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) { int i; + bool is_shadow_vqs_enabled = hdev->shadow_vqs_enabled; /* should only be called after backend is connected */ assert(hdev->vhost_ops); @@ -1805,7 +1880,16 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) if (hdev->vhost_ops->vhost_dev_start) { hdev->vhost_ops->vhost_dev_start(hdev, false); } + if (is_shadow_vqs_enabled) { + /* Shadow virtqueue will be stopped */ + hdev->shadow_vqs_enabled = false; + } for (i = 0; i < hdev->nvqs; ++i) { + if (is_shadow_vqs_enabled) { + vhost_shadow_vq_stop(hdev, i, hdev->shadow_vqs[i]); + vhost_shadow_vq_free(hdev->shadow_vqs[i]); + } + vhost_virtqueue_stop(hdev, vdev, hdev->vqs + i, @@ -1819,6 +1903,8 @@ 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->shadow_vqs_enabled = false; hdev->started = false; hdev->vdev = NULL; } @@ -1835,5 +1921,60 @@ 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); + } }