From patchwork Fri Feb 24 15:54:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 13151474 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C5DF5C61DA4 for ; Fri, 24 Feb 2023 15:57:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pVaQD-0006Ho-8j; Fri, 24 Feb 2023 10:55:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pVaPp-0005cj-8N for qemu-devel@nongnu.org; Fri, 24 Feb 2023 10:55:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pVaPn-0005sz-09 for qemu-devel@nongnu.org; Fri, 24 Feb 2023 10:55:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677254115; 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=Frk975xz6+Mcnrep3pgYyZfXIO/JS3EQ5Ult5wZhqr4=; b=TPutveKoZkJv7xKssZ6kNzyRSxpHTo+lCJOT4wi3CBA2fouy38pPThdFi5o/7zvoEMb2Kg jayBNTosuRZZ7xM3MsRqBovhnmsacW74o3Mt155l9e+8Tr920EzsHorPggPF5J2zgd4tZo wM4gsaMwjcWttK3Br61bBfj+ssEUwI0= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-179-Fclhqr2UMbqu33C5kc0zuw-1; Fri, 24 Feb 2023 10:55:11 -0500 X-MC-Unique: Fclhqr2UMbqu33C5kc0zuw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 434923804530; Fri, 24 Feb 2023 15:55:10 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6461BC15BA0; Fri, 24 Feb 2023 15:55:07 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Stefano Garzarella , Shannon Nelson , Jason Wang , Gautam Dawar , Laurent Vivier , alvaro.karsz@solid-run.com, longpeng2@huawei.com, virtualization@lists.linux-foundation.org, Stefan Hajnoczi , Cindy Lu , "Michael S. Tsirkin" , si-wei.liu@oracle.com, Liuxiangdong , Parav Pandit , Eli Cohen , Zhu Lingshan , Harpreet Singh Anand , "Gonglei (Arei)" , Lei Yang Subject: [PATCH v4 08/15] vdpa: rewind at get_base, not set_base Date: Fri, 24 Feb 2023 16:54:31 +0100 Message-Id: <20230224155438.112797-9-eperezma@redhat.com> In-Reply-To: <20230224155438.112797-1-eperezma@redhat.com> References: <20230224155438.112797-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; 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_H2=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org At this moment it is only possible to migrate to a vdpa device running with x-svq=on. As a protective measure, the rewind of the inflight descriptors was done at the destination. That way if the source sent a virtqueue with inuse descriptors they are always discarded. Since this series allows to migrate also to passthrough devices with no SVQ, the right thing to do is to rewind at the source so the base of vrings are correct. Support for inflight descriptors may be added in the future. Signed-off-by: Eugenio Pérez Acked-by: Jason Wang --- v4: * Use virtqueue_unpop at vhost_svq_stop instead of rewinding at vhost_vdpa_get_vring_base. --- hw/virtio/vhost-shadow-virtqueue.c | 8 ++++++-- hw/virtio/vhost-vdpa.c | 11 ----------- 2 files changed, 6 insertions(+), 13 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 4307296358..523b379439 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -694,13 +694,17 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) g_autofree VirtQueueElement *elem = NULL; elem = g_steal_pointer(&svq->desc_state[i].elem); if (elem) { - virtqueue_detach_element(svq->vq, elem, 0); + /* + * TODO: This is ok for networking, but other kinds of devices + * might have problems with just unpop these. + */ + virtqueue_unpop(svq->vq, elem, 0); } } next_avail_elem = g_steal_pointer(&svq->next_guest_avail_elem); if (next_avail_elem) { - virtqueue_detach_element(svq->vq, next_avail_elem, 0); + virtqueue_unpop(svq->vq, next_avail_elem, 0); } svq->vq = NULL; g_free(svq->desc_next); diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index f542960a64..71e3dc21fe 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -1218,18 +1218,7 @@ static int vhost_vdpa_set_vring_base(struct vhost_dev *dev, struct vhost_vring_state *ring) { struct vhost_vdpa *v = dev->opaque; - VirtQueue *vq = virtio_get_queue(dev->vdev, ring->index); - /* - * vhost-vdpa devices does not support in-flight requests. Set all of them - * as available. - * - * TODO: This is ok for networking, but other kinds of devices might - * have problems with these retransmissions. - */ - while (virtqueue_rewind(vq, 1)) { - continue; - } if (v->shadow_vqs_enabled) { /* * Device vring base was set at device start. SVQ base is handled by