From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O2PtO-0003Sm-Fg for qemu-devel@nongnu.org; Thu, 15 Apr 2010 10:18:06 -0400 Received: from [140.186.70.92] (port=50377 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O2PtM-0003H8-3c for qemu-devel@nongnu.org; Thu, 15 Apr 2010 10:18:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O2Pn2-0000Jj-0C for qemu-devel@nongnu.org; Thu, 15 Apr 2010 10:11:48 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:60136) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O2Pmx-0000HO-8v for qemu-devel@nongnu.org; Thu, 15 Apr 2010 10:11:31 -0400 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by e28smtp03.in.ibm.com (8.14.3/8.13.1) with ESMTP id o3FEBN1R031789 for ; Thu, 15 Apr 2010 19:41:23 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o3FEBNQg3420258 for ; Thu, 15 Apr 2010 19:41:23 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o3FEBMKf030612 for ; Thu, 15 Apr 2010 19:41:22 +0530 From: "Aneesh Kumar K.V" Date: Thu, 15 Apr 2010 19:40:58 +0530 Message-Id: <1271340671-19558-9-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1271340671-19558-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1271340671-19558-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH -V5 08/21] virtio-9p: Add sg helper functions List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: ericvh@gmail.com, aliguori@us.ibm.com, aneesh.kumar@linux.vnet.ibm.com From: Anthony Liguori Add scatter-gather helper functions. Signed-off-by: Anthony Liguori Signed-off-by: Aneesh Kumar K.V --- hw/virtio-9p.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 53 insertions(+), 0 deletions(-) diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c index 4b3ce2f..5dab1d3 100644 --- a/hw/virtio-9p.c +++ b/hw/virtio-9p.c @@ -764,6 +764,56 @@ static int stat_to_v9stat(V9fsState *s, V9fsString *name, return 0; } +static struct iovec *adjust_sg(struct iovec *sg, int len, int *iovcnt) +{ + while (len && *iovcnt) { + if (len < sg->iov_len) { + sg->iov_len -= len; + sg->iov_base += len; + len = 0; + } else { + len -= sg->iov_len; + sg++; + *iovcnt -= 1; + } + } + + return sg; +} + +static struct iovec *cap_sg(struct iovec *sg, int cap, int *cnt) +{ + int i; + int total = 0; + + for (i = 0; i < *cnt; i++) { + if ((total + sg[i].iov_len) > cap) { + sg[i].iov_len -= ((total + sg[i].iov_len) - cap); + i++; + break; + } + total += sg[i].iov_len; + } + + *cnt = i; + + return sg; +} + +static void print_sg(struct iovec *sg, int cnt) +{ + int i; + + printf("sg[%d]: {", cnt); + for (i = 0; i < cnt; i++) { + if (i) { + printf(", "); + } + printf("(%p, %zd)", sg[i].iov_base, sg[i].iov_len); + } + printf("}\n"); +} + static void v9fs_dummy(V9fsState *s, V9fsPDU *pdu) { /* Note: The following have been added to prevent GCC from complaining @@ -788,6 +838,9 @@ static void v9fs_dummy(V9fsState *s, V9fsPDU *pdu) (void) donttouch_stat; (void) v9fs_stat_free; (void) stat_to_v9stat; + (void) adjust_sg; + (void) cap_sg; + (void) print_sg; } static void v9fs_version(V9fsState *s, V9fsPDU *pdu) -- 1.7.0.4.360.g11766c