From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Mon, 26 Jan 2015 05:14:58 +0000 (-0800)
Subject: vhost/scsi: Add ANY_LAYOUT support in vhost_scsi_handle_vq
X-Git-Tag: omap-for-v4.1/prcm-dts-mfd-syscon-fix~13^2~17
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09b13fa8c1a1093e9458549ac8bb203a7c65c62a;p=pandora-kernel.git

vhost/scsi: Add ANY_LAYOUT support in vhost_scsi_handle_vq

This patch adds ANY_LAYOUT compatible support within the existing
vhost_scsi_handle_vq() ->handle_kick() callback.

It calculates data_direction + exp_data_len for the new tcm_vhost_cmd
descriptor by walking both outgoing + incoming iovecs using iov_iter,
assuming the layout of outgoing request header + T10_PI + Data payload
comes first.

It also uses copy_from_iter() to copy leading virtio-scsi request header
that may or may not include SCSI CDB, that returns a re-calculated iovec
to start of T10_PI or Data SGL memory.

Also, go ahead and drop the legacy pre virtio v1.0 !ANY_LAYOUT logic.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---

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