From patchwork Wed Jul 18 15:07:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1211651 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id AB2AB40071 for ; Wed, 18 Jul 2012 15:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754835Ab2GRPJB (ORCPT ); Wed, 18 Jul 2012 11:09:01 -0400 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:43972 "EHLO e06smtp12.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754811Ab2GRPIs (ORCPT ); Wed, 18 Jul 2012 11:08:48 -0400 Received: from /spool/local by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 18 Jul 2012 16:08:47 +0100 Received: from d06nrmr1806.portsmouth.uk.ibm.com (9.149.39.193) by e06smtp12.uk.ibm.com (192.168.101.142) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 18 Jul 2012 16:08:36 +0100 Received: from d06av06.portsmouth.uk.ibm.com (d06av06.portsmouth.uk.ibm.com [9.149.37.217]) by d06nrmr1806.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q6IF8aIX1990902 for ; Wed, 18 Jul 2012 16:08:36 +0100 Received: from d06av06.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q6IF8Zd2013334 for ; Wed, 18 Jul 2012 09:08:35 -0600 Received: from localhost (sig-9-145-185-169.de.ibm.com [9.145.185.169]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q6IF8Yx5013316; Wed, 18 Jul 2012 09:08:34 -0600 From: Stefan Hajnoczi To: Cc: , Anthony Liguori , Kevin Wolf , Paolo Bonzini , "Michael S. Tsirkin" , Asias He , Khoa Huynh , Stefan Hajnoczi Subject: [RFC v9 13/27] virtio-blk: Increase max requests for indirect vring Date: Wed, 18 Jul 2012 16:07:40 +0100 Message-Id: <1342624074-24650-14-git-send-email-stefanha@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1342624074-24650-1-git-send-email-stefanha@linux.vnet.ibm.com> References: <1342624074-24650-1-git-send-email-stefanha@linux.vnet.ibm.com> x-cbid: 12071815-8372-0000-0000-00000339CE10 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org With indirect vring descriptors, one can no longer assume that the maximum number of requests is VRING_MAX / 2 (outhdr and inhdr). Now a single indirect descriptor can contain the outhdr and inhdr so max requests becomes VRING_MAX. Signed-off-by: Stefan Hajnoczi --- hw/virtio-blk.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 591eace..7ae3c56 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -26,7 +26,9 @@ enum { SEG_MAX = 126, /* maximum number of I/O segments */ VRING_MAX = SEG_MAX + 2, /* maximum number of vring descriptors */ - REQ_MAX = VRING_MAX / 2, /* maximum number of requests in the vring */ + REQ_MAX = VRING_MAX, /* maximum number of requests in the vring, + * is VRING_MAX / 2 with traditional and + * VRING_MAX with indirect descriptors */ }; typedef struct {