From patchwork Thu Mar 31 18:03:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 1611896 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=gAyrzoXv; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4KTrmy3wdZz9sG4 for ; Fri, 1 Apr 2022 05:05:06 +1100 (AEDT) Received: from localhost ([::1]:60244 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZzAO-0003PB-3F for incoming@patchwork.ozlabs.org; Thu, 31 Mar 2022 14:05:04 -0400 Received: from eggs.gnu.org ([209.51.188.92]:43814) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZz9m-0003Nt-Be for qemu-devel@nongnu.org; Thu, 31 Mar 2022 14:04:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:59135) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZz9k-0007Jn-92 for qemu-devel@nongnu.org; Thu, 31 Mar 2022 14:04:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648749863; 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=1geVC60KOCBqYcV0yzBh5c9nGhEBBky47+bYEoJUFqQ=; b=gAyrzoXvVH7GWhpdKVdH8S1WtI2Y9UlSojtQPQ/3THmOYIzrUgNFtWuWrYNWkd07Rfc9B0 1wQJfEak4ZWYdGNktmsN0J7QGd115XTuqCtj3KXAhT13lGXnecPKJZfVzTbDakSHgByImt tf9v8QqfMPNULupWS/o9vHk7zokI7eQ= 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-468-Lu7TbR_3O7uawgSaYmvItA-1; Thu, 31 Mar 2022 14:04:18 -0400 X-MC-Unique: Lu7TbR_3O7uawgSaYmvItA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 597CE3C01C00; Thu, 31 Mar 2022 18:04:18 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.194.94]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1FAB840D0160; Thu, 31 Mar 2022 18:04:15 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC PATCH v4 01/20] vhost: Fix bad return of descriptors Date: Thu, 31 Mar 2022 20:03:51 +0200 Message-Id: <20220331180410.531837-2-eperezma@redhat.com> In-Reply-To: <20220331180410.531837-1-eperezma@redhat.com> References: <20220331180410.531837-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eperezma@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; 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, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Cc: Laurent Vivier , Parav Pandit , Cindy Lu , "Michael S. Tsirkin" , Jason Wang , Markus Armbruster , Gautam Dawar , Harpreet Singh Anand , Peter Xu , Eli Cohen , Liuxiangdong , Zhu Lingshan Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Only the first one of them were properly enqueued back. Fixes: 100890f7ca ("vhost: Shadow virtqueue buffers forwarding") Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index b232803d1b..c17506df20 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -333,13 +333,25 @@ static void vhost_svq_disable_notification(VhostShadowVirtqueue *svq) svq->vring.avail->flags |= cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT); } +static uint16_t vhost_svq_last_desc_of_chain(VhostShadowVirtqueue *svq, + uint16_t i) +{ + vring_desc_t *descs = svq->vring.desc; + + while (le16_to_cpu(descs[i].flags) & VRING_DESC_F_NEXT) { + i = le16_to_cpu(descs[i].next); + } + + return i; +} + static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq, uint32_t *len) { vring_desc_t *descs = svq->vring.desc; const vring_used_t *used = svq->vring.used; vring_used_elem_t used_elem; - uint16_t last_used; + uint16_t last_used, last_used_chain; if (!vhost_svq_more_used(svq)) { return NULL; @@ -365,7 +377,8 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq, return NULL; } - descs[used_elem.id].next = svq->free_head; + last_used_chain = vhost_svq_last_desc_of_chain(svq, used_elem.id); + descs[last_used_chain].next = svq->free_head; svq->free_head = used_elem.id; *len = used_elem.len;