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 8488CC43334 for ; Wed, 20 Jul 2022 09:11:44 +0000 (UTC) Received: from localhost ([::1]:55254 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oE5k7-0003nt-Mj for qemu-devel@archiver.kernel.org; Wed, 20 Jul 2022 05:11:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58352) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oE5cN-00089L-D7 for qemu-devel@nongnu.org; Wed, 20 Jul 2022 05:03:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:56570) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oE5cL-0001Ov-PI for qemu-devel@nongnu.org; Wed, 20 Jul 2022 05:03:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658307821; 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=9NSQaMxFBqsbZB36hr3id0dMLvZuFrBmbbdTHzoh6go=; b=P4rBhRPVN2pWhp7WPwbBHu8YagQ1vTuxPE9kVSd1bKouGF5S+hkGz6Qk7R3amtczv4ZF6I 1kTJssIERTM6YDn6p4OZnT/iLIjMawZXY7zhy2CB/vHt0osL1WzPG7TDroRLA4G5zx+mvJ GThw58aV/h6J1vZkRzX4eQV9WvXYtPQ= 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-41-eqhNYJykOyCtyfUJVI0Ymw-1; Wed, 20 Jul 2022 05:03:40 -0400 X-MC-Unique: eqhNYJykOyCtyfUJVI0Ymw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C3DDB1C16B41; Wed, 20 Jul 2022 09:03:39 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-110.pek2.redhat.com [10.72.13.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id 358AE403358; Wed, 20 Jul 2022 09:03:36 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org, peter.maydell@linaro.org Cc: =?UTF-8?q?Eugenio=20P=C3=A9rez?= , "Michael S . Tsirkin" , Jason Wang Subject: [PULL V2 07/25] vhost: Check for queue full at vhost_svq_add Date: Wed, 20 Jul 2022 17:02:55 +0800 Message-Id: <20220720090313.55169-8-jasowang@redhat.com> In-Reply-To: <20220720090313.55169-1-jasowang@redhat.com> References: <20220720090313.55169-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Received-SPF: pass client-ip=170.10.129.124; envelope-from=jasowang@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" From: Eugenio Pérez The series need to expose vhost_svq_add with full functionality, including checking for full queue. Signed-off-by: Eugenio Pérez Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang --- hw/virtio/vhost-shadow-virtqueue.c | 59 +++++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 26 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index e272c33..11302ea 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -233,21 +233,29 @@ static void vhost_svq_kick(VhostShadowVirtqueue *svq) * Add an element to a SVQ. * * The caller must check that there is enough slots for the new element. It - * takes ownership of the element: In case of failure, it is free and the SVQ - * is considered broken. + * takes ownership of the element: In case of failure not ENOSPC, it is free. + * + * Return -EINVAL if element is invalid, -ENOSPC if dev queue is full */ -static bool vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *elem) +static int vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *elem) { unsigned qemu_head; - bool ok = vhost_svq_add_split(svq, elem, &qemu_head); + unsigned ndescs = elem->in_num + elem->out_num; + bool ok; + + if (unlikely(ndescs > vhost_svq_available_slots(svq))) { + return -ENOSPC; + } + + ok = vhost_svq_add_split(svq, elem, &qemu_head); if (unlikely(!ok)) { g_free(elem); - return false; + return -EINVAL; } svq->ring_id_maps[qemu_head] = elem; vhost_svq_kick(svq); - return true; + return 0; } /** @@ -274,7 +282,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) while (true) { VirtQueueElement *elem; - bool ok; + int r; if (svq->next_guest_avail_elem) { elem = g_steal_pointer(&svq->next_guest_avail_elem); @@ -286,25 +294,24 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) break; } - if (elem->out_num + elem->in_num > vhost_svq_available_slots(svq)) { - /* - * This condition is possible since a contiguous buffer in GPA - * does not imply a contiguous buffer in qemu's VA - * scatter-gather segments. If that happens, the buffer exposed - * to the device needs to be a chain of descriptors at this - * moment. - * - * SVQ cannot hold more available buffers if we are here: - * queue the current guest descriptor and ignore further kicks - * until some elements are used. - */ - svq->next_guest_avail_elem = elem; - return; - } - - ok = vhost_svq_add(svq, elem); - if (unlikely(!ok)) { - /* VQ is broken, just return and ignore any other kicks */ + r = vhost_svq_add(svq, elem); + if (unlikely(r != 0)) { + if (r == -ENOSPC) { + /* + * This condition is possible since a contiguous buffer in + * GPA does not imply a contiguous buffer in qemu's VA + * scatter-gather segments. If that happens, the buffer + * exposed to the device needs to be a chain of descriptors + * at this moment. + * + * SVQ cannot hold more available buffers if we are here: + * queue the current guest descriptor and ignore kicks + * until some elements are used. + */ + svq->next_guest_avail_elem = elem; + } + + /* VQ is full or broken, just return and ignore kicks */ return; } } -- 2.7.4