From patchwork Fri Jan 29 20:54:14 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: 12056575 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 C5067C433DB for ; Fri, 29 Jan 2021 21:07:07 +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 0778164E09 for ; Fri, 29 Jan 2021 21:07:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0778164E09 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]:54988 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l5ayw-0000uQ-1i for qemu-devel@archiver.kernel.org; Fri, 29 Jan 2021 16:07:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57944) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l5anh-0007Jk-VC for qemu-devel@nongnu.org; Fri, 29 Jan 2021 15:55:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:28329) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l5anc-0002pv-GQ for qemu-devel@nongnu.org; Fri, 29 Jan 2021 15:55:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611953722; 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=0cPGpoRxd4fEYQvZIXJavl9w+cFdWJK9vsZiBYUG+JA=; b=S+pE2Pghb8BZpNmZrx0dZqYXB3zCHfx0PP+xSxSHkaJ5I+4dIryAprB5CWNvpid/X+213x t8zvAOs/kFlHSWbonXqRw8mcaVkL2ojKXCBisIgS8tPeN9BJl06g8Sj2kx3YVsrvxjezsN /LbeepS79zWrGEphETl1CXXza+bRj/Q= 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-460-8peUIH-gOe29QMAyRyCXnA-1; Fri, 29 Jan 2021 15:55:21 -0500 X-MC-Unique: 8peUIH-gOe29QMAyRyCXnA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C2EE10054FF; Fri, 29 Jan 2021 20:55:17 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-113-115.ams2.redhat.com [10.36.113.115]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF2E619C66; Fri, 29 Jan 2021 20:55:13 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC 09/10] vhost: Route guest->host notification through shadow virtqueue Date: Fri, 29 Jan 2021 21:54:14 +0100 Message-Id: <20210129205415.876290-10-eperezma@redhat.com> In-Reply-To: <20210129205415.876290-1-eperezma@redhat.com> References: <20210129205415.876290-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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=63.128.21.124; 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=-0.249, 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_H4=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 , 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. Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.h | 5 ++ include/hw/virtio/vhost.h | 4 + hw/virtio/vhost-shadow-virtqueue.c | 123 +++++++++++++++++++++++++- hw/virtio/vhost.c | 135 ++++++++++++++++++++++++++++- 4 files changed, 264 insertions(+), 3 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index 6cc18d6acb..466f8ae595 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -17,6 +17,11 @@ typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; +bool vhost_shadow_vq_start_rcu(struct vhost_dev *dev, + VhostShadowVirtqueue *svq); +void vhost_shadow_vq_stop_rcu(struct vhost_dev *dev, + 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 2be782cefd..732a4b2a2b 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 c0c967a7c5..908c36c66d 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -8,15 +8,129 @@ */ #include "hw/virtio/vhost-shadow-virtqueue.h" +#include "hw/virtio/vhost.h" +#include "hw/virtio/virtio-access.h" + +#include "standard-headers/linux/vhost_types.h" +#include "standard-headers/linux/virtio_ring.h" #include "qemu/error-report.h" -#include "qemu/event_notifier.h" +#include "qemu/main-loop.h" typedef struct VhostShadowVirtqueue { EventNotifier kick_notifier; EventNotifier call_notifier; + const struct vhost_virtqueue *hvq; + VirtIODevice *vdev; + VirtQueue *vq; } VhostShadowVirtqueue; +static uint16_t vhost_shadow_vring_used_flags(VhostShadowVirtqueue *svq) +{ + const struct vring_used *used = svq->hvq->used; + return virtio_tswap16(svq->vdev, used->flags); +} + +static bool vhost_shadow_vring_should_kick(VhostShadowVirtqueue *vq) +{ + return !(vhost_shadow_vring_used_flags(vq) & VRING_USED_F_NO_NOTIFY); +} + +static void vhost_shadow_vring_kick(VhostShadowVirtqueue *vq) +{ + if (vhost_shadow_vring_should_kick(vq)) { + event_notifier_set(&vq->kick_notifier); + } +} + +static void handle_shadow_vq(VirtIODevice *vdev, VirtQueue *vq) +{ + struct vhost_dev *hdev = vhost_dev_from_virtio(vdev); + uint16_t idx = virtio_get_queue_index(vq); + + VhostShadowVirtqueue *svq = hdev->shadow_vqs[idx]; + + vhost_shadow_vring_kick(svq); +} + +/* + * Start shadow virtqueue operation. + * @dev vhost device + * @svq Shadow Virtqueue + * + * Run in RCU context + */ +bool vhost_shadow_vq_start_rcu(struct vhost_dev *dev, + VhostShadowVirtqueue *svq) +{ + const VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(dev->vdev); + EventNotifier *vq_host_notifier = virtio_queue_get_host_notifier(svq->vq); + unsigned idx = virtio_queue_get_idx(svq->vdev, svq->vq); + struct vhost_vring_file kick_file = { + .index = idx, + .fd = event_notifier_get_fd(&svq->kick_notifier), + }; + int r; + bool ok; + + /* Check that notifications are still going directly to vhost dev */ + assert(virtio_queue_host_notifier_status(svq->vq)); + + ok = k->set_vq_handler(dev->vdev, idx, handle_shadow_vq); + if (!ok) { + error_report("Couldn't set the vq handler"); + goto err_set_kick_handler; + } + + r = dev->vhost_ops->vhost_set_vring_kick(dev, &kick_file); + if (r != 0) { + error_report("Couldn't set kick fd: %s", strerror(errno)); + goto err_set_vring_kick; + } + + event_notifier_set_handler(vq_host_notifier, + virtio_queue_host_notifier_read); + virtio_queue_set_host_notifier_enabled(svq->vq, false); + virtio_queue_host_notifier_read(vq_host_notifier); + + return true; + +err_set_vring_kick: + k->set_vq_handler(dev->vdev, idx, NULL); + +err_set_kick_handler: + return false; +} + +/* + * Stop shadow virtqueue operation. + * @dev vhost device + * @svq Shadow Virtqueue + * + * Run in RCU context + */ +void vhost_shadow_vq_stop_rcu(struct vhost_dev *dev, + VhostShadowVirtqueue *svq) +{ + const VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(svq->vdev); + unsigned idx = virtio_queue_get_idx(svq->vdev, svq->vq); + 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(vq_host_notifier, NULL); + virtio_queue_set_host_notifier_enabled(svq->vq, true); + k->set_vq_handler(svq->vdev, idx, NULL); +} + /* * Creates vhost shadow virtqueue, and instruct vhost device to use the shadow * methods and file descriptors. @@ -24,8 +138,13 @@ 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->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + idx); int r; + svq->vq = virtio_get_queue(dev->vdev, vq_idx); + svq->hvq = &dev->vqs[idx]; + svq->vdev = dev->vdev; + r = event_notifier_init(&svq->kick_notifier, 0); if (r != 0) { error_report("Couldn't create kick event notifier: %s", @@ -40,7 +159,7 @@ 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 42836e45f3..bde688f278 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" @@ -945,6 +946,82 @@ 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, 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) { + int stop_idx = idx; + bool ok = vhost_shadow_vq_start_rcu(dev, + dev->shadow_vqs[idx]); + + if (!ok) { + while (--stop_idx >= 0) { + vhost_shadow_vq_stop_rcu(dev, 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) @@ -1389,6 +1466,7 @@ 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); @@ -1816,6 +1894,11 @@ 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, hdev->shadow_vqs[i]); + vhost_shadow_vq_free(hdev->shadow_vqs[i]); + } + vhost_virtqueue_stop(hdev, vdev, hdev->vqs + i, @@ -1829,6 +1912,8 @@ 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; } @@ -1845,5 +1930,53 @@ 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; + const char *err_cause = NULL; + const VirtioDeviceClass *k; + int r; + ErrorClass err_class = ERROR_CLASS_GENERIC_ERROR; + + QLIST_FOREACH(hdev, &vhost_devices, entry) { + if (hdev->vdev && 0 == strcmp(hdev->vdev->name, name)) { + break; + } + } + + if (!hdev) { + err_class = ERROR_CLASS_DEVICE_NOT_FOUND; + err_cause = "Device not found"; + goto err; + } + + if (!hdev->started) { + err_cause = "Device is not started"; + goto err; + } + + if (hdev->acked_features & BIT_ULL(VIRTIO_F_RING_PACKED)) { + err_cause = "Use packed vq"; + goto err; + } + + if (vhost_dev_has_iommu(hdev)) { + err_cause = "Device use IOMMU"; + goto err; + } + + k = VIRTIO_DEVICE_GET_CLASS(hdev->vdev); + if (!k->set_vq_handler) { + err_cause = "Virtio device type does not support reset of vq handler"; + goto err; + } + + r = vhost_sw_live_migration_enable(hdev, enable); + if (unlikely(r)) { + err_cause = "Error enabling (see monitor)"; + } + +err: + if (err_cause) { + error_set(errp, err_class, + "Can't enable shadow vq on %s: %s", name, err_cause); + } }