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 D2823C43334 for ; Tue, 19 Jul 2022 10:13:26 +0000 (UTC) Received: from localhost ([::1]:56168 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oDkEH-0001JO-V0 for qemu-devel@archiver.kernel.org; Tue, 19 Jul 2022 06:13:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50168) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDjyR-0008E1-LY for qemu-devel@nongnu.org; Tue, 19 Jul 2022 05:57:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:40384) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDjyQ-00055X-0J for qemu-devel@nongnu.org; Tue, 19 Jul 2022 05:57:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658224621; 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=h6W/2l6vVPJQ+V1MhR2WFP0BYdPkLezivgYrVHhlzMA=; b=OQvZACbmd/GgavWjk/5kqtXRwpIrEVcnlaZZoDSZNgfGKfuTHpfnCZ20LkY9xi0P9BGLrH Nq3oxsc0K/FiZr3mpw62JQZWD8udF4qVYn3fco1s2Th29Izd/m4LHmWySA8qUdafl1iH5T tDOzxxJ6MABGfE8OaEapf7A8xt2Pih4= 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-43-knczKPAKNneSICJnJY8HVg-1; Tue, 19 Jul 2022 05:56:57 -0400 X-MC-Unique: knczKPAKNneSICJnJY8HVg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8CDDE1C006A5; Tue, 19 Jul 2022 09:56:56 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.113]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC6DB18EB7; Tue, 19 Jul 2022 09:56:53 +0000 (UTC) From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Gautam Dawar , Liuxiangdong , Paolo Bonzini , Markus Armbruster , Jason Wang , Cornelia Huck , Parav Pandit , Eric Blake , "Michael S. Tsirkin" , Laurent Vivier , Zhu Lingshan , Eli Cohen , Cindy Lu , "Gonglei (Arei)" , Stefano Garzarella , Harpreet Singh Anand Subject: [PATCH v5 07/20] vhost: Check for queue full at vhost_svq_add Date: Tue, 19 Jul 2022 11:56:16 +0200 Message-Id: <20220719095629.3031338-8-eperezma@redhat.com> In-Reply-To: <20220719095629.3031338-1-eperezma@redhat.com> References: <20220719095629.3031338-1-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 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" The series need to expose vhost_svq_add with full functionality, including checking for full queue. Signed-off-by: Eugenio Pérez --- 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 e272c3318a..11302ea1f2 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; } } -- 2.31.1