From patchwork Fri Nov 20 18:50:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 11922005 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=unavailable 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 8E65AC2D0E4 for ; Fri, 20 Nov 2020 19:02:58 +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 CC70520760 for ; Fri, 20 Nov 2020 19:02:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QLgW7Thk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC70520760 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]:54460 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kgBgO-0005tv-KJ for qemu-devel@archiver.kernel.org; Fri, 20 Nov 2020 14:02:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41370) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kgBYM-0006Kb-H0 for qemu-devel@nongnu.org; Fri, 20 Nov 2020 13:54:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40787) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kgBYJ-0007dN-O3 for qemu-devel@nongnu.org; Fri, 20 Nov 2020 13:54:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605898473; 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=DBP6ZYk56FcgCXgaWqpbvzcgYqNFQcFTrZnQ3USZwTQ=; b=QLgW7ThkHg9++LdDA7A4xuZD2t4QbDVsCdYuwFze2SH/swZU6G8R/G1TWnKiHokSKv/9IG b+Kk9KVzl/mYk+elhAaPzolgrWMmv/2eszT3QYuOVBKO4v2E52V+ygGve1jp9O3Bc+8hwk MV5sRFzn7gAZp4t/zRQKlQvR/4rZVAo= 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-289-lEeqo5FhPaaoSZsN_h9FbQ-1; Fri, 20 Nov 2020 13:54:31 -0500 X-MC-Unique: lEeqo5FhPaaoSZsN_h9FbQ-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 64E8B184215F; Fri, 20 Nov 2020 18:54:28 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-112-88.ams2.redhat.com [10.36.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id BD0785C1D5; Fri, 20 Nov 2020 18:54:08 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC PATCH 13/27] vhost: Send buffers to device Date: Fri, 20 Nov 2020 19:50:51 +0100 Message-Id: <20201120185105.279030-14-eperezma@redhat.com> In-Reply-To: <20201120185105.279030-1-eperezma@redhat.com> References: <20201120185105.279030-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: kvm@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Daniel Daly , virtualization@lists.linux-foundation.org, Liran Alon , Eli Cohen , Nitin Shrivastav , Alex Barba , Christophe Fontaine , Juan Quintela , Lee Ballard , Lars Ganrot , Rob Miller , Stefano Garzarella , Howard Cai , Parav Pandit , vm , Salil Mehta , Stephen Finucane , Xiao W Wang , Sean Mooney , Stefan Hajnoczi , Jim Harford , Dmytro Kazantsev , Siwei Liu , Harpreet Singh Anand , Michael Lilja , Max Gurtovoy Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-sw-lm-ring.h | 3 + hw/virtio/vhost-sw-lm-ring.c | 134 +++++++++++++++++++++++++++++++++-- hw/virtio/vhost.c | 59 ++++++++++++++- 3 files changed, 189 insertions(+), 7 deletions(-) diff --git a/hw/virtio/vhost-sw-lm-ring.h b/hw/virtio/vhost-sw-lm-ring.h index 86dc081b93..29d21feaf4 100644 --- a/hw/virtio/vhost-sw-lm-ring.h +++ b/hw/virtio/vhost-sw-lm-ring.h @@ -18,6 +18,9 @@ typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; bool vhost_vring_kick(VhostShadowVirtqueue *vq); +int vhost_vring_add(VhostShadowVirtqueue *vq, VirtQueueElement *elem); +void vhost_vring_write_addr(const VhostShadowVirtqueue *vq, + struct vhost_vring_addr *addr); VhostShadowVirtqueue *vhost_sw_lm_shadow_vq(struct vhost_dev *dev, int idx); diff --git a/hw/virtio/vhost-sw-lm-ring.c b/hw/virtio/vhost-sw-lm-ring.c index cd7b5ba772..aed005c2d9 100644 --- a/hw/virtio/vhost-sw-lm-ring.c +++ b/hw/virtio/vhost-sw-lm-ring.c @@ -9,6 +9,7 @@ #include "hw/virtio/vhost-sw-lm-ring.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" @@ -19,21 +20,140 @@ typedef struct VhostShadowVirtqueue { struct vring vring; EventNotifier hdev_notifier; VirtQueue *vq; + VirtIODevice *vdev; + + /* Map for returning guest's descriptors */ + VirtQueueElement **ring_id_maps; + + /* Next head to expose to device */ + uint16_t avail_idx_shadow; + + /* Number of descriptors added since last notification */ + uint16_t num_added; + + /* Next free descriptor */ + uint16_t free_head; vring_desc_t descs[]; } VhostShadowVirtqueue; -static inline bool vhost_vring_should_kick(VhostShadowVirtqueue *vq) +static bool vhost_vring_should_kick_rcu(VhostShadowVirtqueue *vq) { - return virtio_queue_get_used_notify_split(vq->vq); + VirtIODevice *vdev = vq->vdev; + vq->num_added = 0; + + smp_rmb(); + return !(vq->vring.used->flags + & virtio_tswap16(vdev, VRING_USED_F_NO_NOTIFY)); } +static bool vhost_vring_should_kick(VhostShadowVirtqueue *vq) +{ + RCU_READ_LOCK_GUARD(); + return vhost_vring_should_kick_rcu(vq); +} + + bool vhost_vring_kick(VhostShadowVirtqueue *vq) { return vhost_vring_should_kick(vq) ? event_notifier_set(&vq->hdev_notifier) : true; } +static void vhost_vring_write_descs(VhostShadowVirtqueue *vq, + const struct iovec *iovec, + size_t num, bool more_descs, bool write) +{ + uint16_t i = vq->free_head, last = vq->free_head; + unsigned n; + const VirtIODevice *vdev = vq->vdev; + uint16_t flags = write ? virtio_tswap16(vdev, VRING_DESC_F_WRITE) : 0; + vring_desc_t *descs = vq->vring.desc; + + if (num == 0) { + return; + } + + for (n = 0; n < num; n++) { + if (more_descs || (n + 1 < num)) { + descs[i].flags = flags | virtio_tswap16(vdev, VRING_DESC_F_NEXT); + } else { + descs[i].flags = flags; + } + descs[i].addr = virtio_tswap64(vdev, (hwaddr)iovec[n].iov_base); + descs[i].len = virtio_tswap32(vdev, iovec[n].iov_len); + + last = i; + i = virtio_tswap16(vdev, descs[i].next); + } + + vq->free_head = virtio_tswap16(vdev, descs[last].next); +} + +/* virtqueue_add: + * @vq: The #VirtQueue + * @elem: The #VirtQueueElement + * + * Add an avail element to a virtqueue. + */ +static int vhost_vring_add_split(VhostShadowVirtqueue *vq, + const VirtQueueElement *elem) +{ + int head; + unsigned avail_idx; + const VirtIODevice *vdev; + vring_avail_t *avail; + + RCU_READ_LOCK_GUARD(); + vdev = vq->vdev; + avail = vq->vring.avail; + + head = vq->free_head; + + /* We need some descriptors here */ + assert(elem->out_num || elem->in_num); + + vhost_vring_write_descs(vq, elem->out_sg, elem->out_num, + elem->in_num > 0, false); + vhost_vring_write_descs(vq, elem->in_sg, elem->in_num, false, true); + + /* Put entry in available array (but don't update avail->idx until they + * do sync). */ + avail_idx = vq->avail_idx_shadow & (vq->vring.num - 1); + avail->ring[avail_idx] = virtio_tswap16(vdev, head); + vq->avail_idx_shadow++; + + /* Expose descriptors to device */ + smp_wmb(); + avail->idx = virtio_tswap16(vdev, vq->avail_idx_shadow); + + /* threoretically possible. Kick just in case */ + if (unlikely(vq->num_added++ == (uint16_t)-1)) { + vhost_vring_kick(vq); + } + + return head; +} + +int vhost_vring_add(VhostShadowVirtqueue *vq, VirtQueueElement *elem) +{ + int host_head = vhost_vring_add_split(vq, elem); + if (vq->ring_id_maps[host_head]) { + g_free(vq->ring_id_maps[host_head]); + } + + vq->ring_id_maps[host_head] = elem; + return 0; +} + +void vhost_vring_write_addr(const VhostShadowVirtqueue *vq, + struct vhost_vring_addr *addr) +{ + addr->desc_user_addr = (uint64_t)vq->vring.desc; + addr->avail_user_addr = (uint64_t)vq->vring.avail; + addr->used_user_addr = (uint64_t)vq->vring.used; +} + VhostShadowVirtqueue *vhost_sw_lm_shadow_vq(struct vhost_dev *dev, int idx) { struct vhost_vring_file file = { @@ -43,9 +163,11 @@ VhostShadowVirtqueue *vhost_sw_lm_shadow_vq(struct vhost_dev *dev, int idx) unsigned num = virtio_queue_get_num(dev->vdev, idx); size_t ring_size = vring_size(num, VRING_DESC_ALIGN_SIZE); VhostShadowVirtqueue *svq; - int r; + int r, i; svq = g_malloc0(sizeof(*svq) + ring_size); + svq->ring_id_maps = g_new0(VirtQueueElement *, num); + svq->vdev = dev->vdev; svq->vq = vq; r = event_notifier_init(&svq->hdev_notifier, 0); @@ -55,8 +177,9 @@ VhostShadowVirtqueue *vhost_sw_lm_shadow_vq(struct vhost_dev *dev, int idx) r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); assert(r == 0); - vhost_virtqueue_mask(dev, dev->vdev, idx, true); - vhost_virtqueue_pending(dev, idx); + vring_init(&svq->vring, num, svq->descs, VRING_DESC_ALIGN_SIZE); + for (i = 0; i < num - 1; i++) + svq->descs[i].next = virtio_tswap16(dev->vdev, i + 1); return svq; } @@ -64,5 +187,6 @@ VhostShadowVirtqueue *vhost_sw_lm_shadow_vq(struct vhost_dev *dev, int idx) void vhost_sw_lm_shadow_vq_free(VhostShadowVirtqueue *vq) { event_notifier_cleanup(&vq->hdev_notifier); + g_free(vq->ring_id_maps); g_free(vq); } diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 9352c56bfa..304e0baa61 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -956,8 +956,34 @@ static void handle_sw_lm_vq(VirtIODevice *vdev, VirtQueue *vq) uint16_t idx = virtio_get_queue_index(vq); VhostShadowVirtqueue *svq = hdev->sw_lm_shadow_vq[idx]; + VirtQueueElement *elem; - vhost_vring_kick(svq); + /* + * Make available all buffers as possible. + */ + do { + if (virtio_queue_get_notification(vq)) { + virtio_queue_set_notification(vq, false); + } + + while (true) { + int r; + if (virtio_queue_full(vq)) { + break; + } + + elem = virtqueue_pop(vq, sizeof(*elem)); + if (!elem) { + break; + } + + r = vhost_vring_add(svq, elem); + assert(r >= 0); + vhost_vring_kick(svq); + } + + virtio_queue_set_notification(vq, true); + } while(!virtio_queue_empty(vq)); } static void vhost_handle_call(EventNotifier *n) @@ -975,6 +1001,11 @@ static void vhost_handle_call(EventNotifier *n) } } +static void vhost_virtqueue_stop(struct vhost_dev *dev, + struct VirtIODevice *vdev, + struct vhost_virtqueue *vq, + unsigned idx); + static int vhost_sw_live_migration_stop(struct vhost_dev *dev) { int idx; @@ -991,17 +1022,41 @@ static int vhost_sw_live_migration_stop(struct vhost_dev *dev) static int vhost_sw_live_migration_start(struct vhost_dev *dev) { - int idx; + int idx, r; + + assert(dev->vhost_ops->vhost_set_vring_enable); + dev->vhost_ops->vhost_set_vring_enable(dev, false); for (idx = 0; idx < dev->nvqs; ++idx) { struct vhost_virtqueue *vq = &dev->vqs[idx]; + struct vhost_vring_addr addr = { + .index = idx, + }; + struct vhost_vring_state s = { + .index = idx, + }; + + vhost_virtqueue_stop(dev, dev->vdev, &dev->vqs[idx], idx); dev->sw_lm_shadow_vq[idx] = vhost_sw_lm_shadow_vq(dev, idx); event_notifier_set_handler(&vq->masked_notifier, vhost_handle_call); + + vhost_vring_write_addr(dev->sw_lm_shadow_vq[idx], &addr); + r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); + assert(r == 0); + + r = dev->vhost_ops->vhost_set_vring_base(dev, &s); + assert(r == 0); } + dev->vhost_ops->vhost_set_vring_enable(dev, true); vhost_dev_disable_notifiers(dev, dev->vdev); + for (idx = 0; idx < dev->nvqs; ++idx) { + vhost_virtqueue_mask(dev, dev->vdev, idx, true); + vhost_virtqueue_pending(dev, idx); + } + return 0; }