From mboxrd@z Thu Jan 1 00:00:00 1970 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 3F33FC433F5 for ; Thu, 19 May 2022 19:24:55 +0000 (UTC) Received: from localhost ([::1]:43450 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nrllW-0005hd-BA for qemu-devel@archiver.kernel.org; Thu, 19 May 2022 15:24:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48168) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nrlam-0005OB-A1 for qemu-devel@nongnu.org; Thu, 19 May 2022 15:13:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:56816) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nrlak-0006PL-G7 for qemu-devel@nongnu.org; Thu, 19 May 2022 15:13:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652987623; 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=4Rk5vuJjlEY7VO/1pCIBCwcJaBWNUxkAO+ircCyr+84=; b=f8m+oPNaG4+er28xWKz8GpdLbdmlsKoUNJ/59iOuhd5SAfqtYyrvewvZdBvEeYQVaXfWAf Zbc3giRTGNEsgxo9OSd7VsBnNil7AyKad2rPzAY29lr8Bw39RQ4cdnerxIrIqoB2Llh20i J31Od8pm3wftbgeJd3ybwPMOnAHx5BU= 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-401-LTRMZHbePYyNPZUxoVGy8w-1; Thu, 19 May 2022 15:13:40 -0400 X-MC-Unique: LTRMZHbePYyNPZUxoVGy8w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3956A29AB3E1; Thu, 19 May 2022 19:13:40 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.193.126]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9F4962026D6A; Thu, 19 May 2022 19:13:37 +0000 (UTC) From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Gautam Dawar , "Michael S. Tsirkin" , Markus Armbruster , "Gonglei (Arei)" , Harpreet Singh Anand , Cornelia Huck , Zhu Lingshan , Laurent Vivier , Eli Cohen , Paolo Bonzini , Liuxiangdong , Eric Blake , Cindy Lu , Jason Wang , Parav Pandit Subject: [RFC PATCH v8 10/21] vhost: Add vhost_svq_inject Date: Thu, 19 May 2022 21:12:55 +0200 Message-Id: <20220519191306.821774-11-eperezma@redhat.com> In-Reply-To: <20220519191306.821774-1-eperezma@redhat.com> References: <20220519191306.821774-1-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 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: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" This allows qemu to inject buffers to the device without guest's notice. This will be use to inject net CVQ messages to restore status in the destination. Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.h | 5 +++ hw/virtio/vhost-shadow-virtqueue.c | 72 +++++++++++++++++++++++++----- 2 files changed, 65 insertions(+), 12 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index 79cb2d301f..8fe0367944 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -23,6 +23,9 @@ typedef struct SVQElement { /* Length of in buffer */ size_t in_len; + + /* Buffer has been injected by QEMU, not by the guest */ + bool not_from_guest; } SVQElement; typedef void (*VirtQueueElementCallback)(VirtIODevice *vdev, @@ -115,6 +118,8 @@ typedef struct VhostShadowVirtqueue { bool vhost_svq_valid_features(uint64_t features, Error **errp); +int vhost_svq_inject(VhostShadowVirtqueue *svq, const struct iovec *iov, + size_t out_num, size_t in_num); void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd); void vhost_svq_set_svq_call_fd(VhostShadowVirtqueue *svq, int call_fd); void vhost_svq_get_vring_addr(const VhostShadowVirtqueue *svq, diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 5a8feb1cbc..c535c99905 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -312,6 +312,43 @@ static void vhost_svq_kick(VhostShadowVirtqueue *svq) event_notifier_set(&svq->hdev_kick); } +/** + * Inject a chain of buffers to the device + * + * @svq: Shadow VirtQueue + * @iov: Descriptors buffer + * @out_num: Number of out elements + * @in_num: Number of in elements + */ +int vhost_svq_inject(VhostShadowVirtqueue *svq, const struct iovec *iov, + size_t out_num, size_t in_num) +{ + SVQElement *svq_elem; + uint16_t num_slots = (in_num ? 1 : 0) + (out_num ? 1 : 0); + + /* + * To inject buffers in a SVQ that does not copy descriptors is not + * supported. All vhost_svq_inject calls are controlled by qemu so we won't + * hit these assertions. + */ + assert(svq->copy_descs); + assert(num_slots > 0); + + if (unlikely(svq->next_guest_avail_elem)) { + error_report("Injecting in a full queue"); + return -ENOMEM; + } + + svq_elem = virtqueue_alloc_element(sizeof(*svq_elem), out_num, in_num); + iov_copy(svq_elem->elem.in_sg, in_num, iov + out_num, in_num, 0, SIZE_MAX); + iov_copy(svq_elem->elem.out_sg, out_num, iov, out_num, 0, SIZE_MAX); + svq_elem->not_from_guest = true; + vhost_svq_add(svq, svq_elem); + vhost_svq_kick(svq); + + return 0; +} + /** * Forward available buffers. * @@ -350,6 +387,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) break; } + svq_elem->not_from_guest = false; elem = &svq_elem->elem; needed_slots = svq->copy_descs ? 1 : elem->out_num + elem->in_num; if (needed_slots > vhost_svq_available_slots(svq)) { @@ -575,19 +613,24 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq, svq->ops->used_elem_handler(svq->vdev, elem); } - if (unlikely(i >= svq->vring.num)) { - qemu_log_mask(LOG_GUEST_ERROR, - "More than %u used buffers obtained in a %u size SVQ", - i, svq->vring.num); - virtqueue_fill(vq, elem, len, i); - virtqueue_flush(vq, i); - return; + if (!svq_elem->not_from_guest) { + if (unlikely(i >= svq->vring.num)) { + qemu_log_mask( + LOG_GUEST_ERROR, + "More than %u used buffers obtained in a %u size SVQ", + i, svq->vring.num); + virtqueue_fill(vq, elem, len, i); + virtqueue_flush(vq, i); + return; + } + virtqueue_fill(vq, elem, len, i++); } - virtqueue_fill(vq, elem, len, i++); } - virtqueue_flush(vq, i); - event_notifier_set(&svq->svq_call); + if (i > 0) { + virtqueue_flush(vq, i); + event_notifier_set(&svq->svq_call); + } if (check_for_avail_queue && svq->next_guest_avail_elem) { /* @@ -755,7 +798,10 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) if (svq->copy_descs) { vhost_svq_unmap_elem(svq, svq_elem, 0, false); } - virtqueue_detach_element(svq->vq, &svq_elem->elem, 0); + + if (!svq_elem->not_from_guest) { + virtqueue_detach_element(svq->vq, &svq_elem->elem, 0); + } } } @@ -764,7 +810,9 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) if (svq->copy_descs) { vhost_svq_unmap_elem(svq, next_avail_elem, 0, false); } - virtqueue_detach_element(svq->vq, &next_avail_elem->elem, 0); + if (!next_avail_elem->not_from_guest) { + virtqueue_detach_element(svq->vq, &next_avail_elem->elem, 0); + } } svq->vq = NULL; g_free(svq->desc_next); -- 2.27.0