Messages in this thread | | | From | "Nicholas A. Bellinger" <> | Subject | [RFCv2 0/7] vhost/scsi: Add T10 PI SGL passthrough support | Date | Mon, 17 Mar 2014 05:32:54 +0000 |
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From: Nicholas Bellinger <nab@linux-iscsi.org>
Hi MST, MKP, Paolo & Co,
This is an updated -v2 series for adding T1O protection information (PI) SGL passthrough support between virtio-scsi LLD + vhost-scsi fabric endpoints.
The patch series is available at:
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending.git vhost-dif
Following Paolo's recommendations, this patch adds a new virtio_scsi command header (virtio_scsi_cmd_req_pi) with the following elements to signal the existence of protection information:
->do_pi_niov (DataOUT PI number of iovecs) ->di_pi_noiv (DataIN PI number of iovecs)
Also included is the change to attach protection information preceeding the actual DataOUT + DataIN data payload, thus making a future improvement of processing virtio buffers inline a possibility.
vhost-scsi code has also been updated to determine virtio_scsi_cmd_req or virtio_scsi_cmd_req_pi usage based upon the first iovec's (header) length, and then continues to process in either mode accordingly.
As with the original RFC, the virtio-scsi patch still contains a hack to force DIX/DIF to be enabled, regardless of host provided feature bits. This regression bug still needs to be tracked down.
v2 changes: - Add virtio_scsi_cmd_req_pi header (Paolo + nab) - Use virtio_scsi_cmd_req_pi instead of existing ->prio (Paolo + nab) - Make protection buffer come before data buffer (Paolo + nab) - Update vhost_scsi_get_tag() parameter usage (nab)
Please review.
Thanks!
--nab
Nicholas Bellinger (7): virtio-scsi.h: Add virtio_scsi_cmd_req_pi header definition vhost/scsi: Move sanity check into vhost_scsi_map_iov_to_sgl vhost/scsi: Add preallocation of protection SGLs vhost/scsi: Add T10 PI IOV -> SGL memory mapping logic vhost/scsi: Enable T10 PI IOV -> SGL memory mapping vhost/scsi: Add new VIRTIO_SCSI_F_T10_PI feature bit virtio-scsi: Enable DIF/DIX modes in SCSI host LLD
drivers/scsi/virtio_scsi.c | 79 +++++++++--- drivers/vhost/scsi.c | 289 +++++++++++++++++++++++++++++-------------- include/linux/virtio_scsi.h | 15 ++- 3 files changed, 273 insertions(+), 110 deletions(-)
-- 1.7.2.5
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