Messages in this thread | | | Date | Mon, 14 Jun 2010 15:22:49 +0900 | Subject | Re: [PATCH] [BSG]: Add support for struct sg_io_v4->d[out,in]_iovec_count | From | FUJITA Tomonori <> |
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On Sun, 13 Jun 2010 23:11:29 -0700 "Nicholas A. Bellinger" <nab@linux-iscsi.org> wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org> > > Greetings Jens and co, > > This patch adds the missing support to block/bsg.c:bsg_map_hdr() to accept > struct sg_io_v4->d[out,in]_iovec_count and process struct sg_io_v4->d[out,in]_xferp memory > containing userspace iovecs for kernel level BSG. It adds a new wrapper bsg_rq_map_user_iov() > that will call copy_from_user() and blk_rq_map_user_iov() following the original SG_IO logic in > drivers/scsi/sg.c:sg_start_req(). > > So far this has been tested on a x86_64 v2.6.34 KVM Host with TCM_Loop Virtual SAS Port/LUNs > into a x86_64 v2.6.26 KVM Guest with Megasas 8707EM2 HBA Emulation + my new scsi-bsg backstore code. > > Please consider this for v2.6.36 as it will be required in order for QEMU-KVM MegaSAS and VirtIO HBA > emulation using QEMU scatterlist memory and BSG backstores. > > Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org> > --- > block/bsg.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++-------- > 1 files changed, 47 insertions(+), 8 deletions(-)
This have been rejected several times.
This doesn't work on 32bit user/64bit kernel.
The compat code doesn't work for the read/write interface (does for the ioctl interface though). So we can't support this feature cleanly.
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