From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:52907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SrVrl-0005VD-55 for qemu-devel@nongnu.org; Wed, 18 Jul 2012 11:08:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SrVrk-0000k7-3I for qemu-devel@nongnu.org; Wed, 18 Jul 2012 11:08:41 -0400 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:49677) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SrVrj-0000jz-QB for qemu-devel@nongnu.org; Wed, 18 Jul 2012 11:08:40 -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 16:08:39 +0100 Received: from d06av06.portsmouth.uk.ibm.com (d06av06.portsmouth.uk.ibm.com [9.149.37.217]) by d06nrmr1507.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q6IF8ZFM2412642 for ; Wed, 18 Jul 2012 16:08:35 +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 q6IF8Zcu013334 for ; Wed, 18 Jul 2012 09:08:35 -0600 From: Stefan Hajnoczi Date: Wed, 18 Jul 2012 16:07:40 +0100 Message-Id: <1342624074-24650-14-git-send-email-stefanha@linux.vnet.ibm.com> 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> Subject: [Qemu-devel] [RFC v9 13/27] virtio-blk: Increase max requests for indirect vring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Anthony Liguori , Stefan Hajnoczi , kvm@vger.kernel.org, "Michael S. Tsirkin" , Khoa Huynh , Paolo Bonzini , Asias He 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 { -- 1.7.10.4