This adds virtio-scsi multi-queue support to tcm_vhost. In order to use
multi-queue, guest side multi-queue support is need. It can
be found here:
https://lkml.org/lkml/2012/12/18/166
Currently, only one thread is created by vhost core code for each
vhost_scsi instance. Even if there are multi-queues, all the handling of
guest kick (vhost_scsi_handle_kick) are processed in one thread. This is
not optimal. Luckily, most of the work is offloaded to the tcm_vhost
workqueue.
Some initial perf numbers:
1 queue, 4 targets, 1 lun per target
4K request size, 50% randread + 50% randwrite: 127K/127k IOPS
4 queues, 4 targets, 1 lun per target
4K request size, 50% randread + 50% randwrite: 181K/181k IOPS
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
In order to take advantages of Paolo's multi-queue virito-scsi, we need
multi-target support in tcm_vhost first. Otherwise all the requests go
to one queue and other queues are idle.
This patch makes:
1. All the targets under the wwpn is seen and can be used by guest.
2. No need to pass the tpgt number in struct vhost_scsi_target to
tcm_vhost.ko. Only wwpn is needed.
3. We can always pass max_target = 255 to guest now, since we abort the
request who's target id does not exist.
Changes in v2:
- Handle non-contiguous tpgt
Changes in v3:
- Simplfy lock in vhost_scsi_set_endpoint
- Return -EEXIST when does not match
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We can get all the pages in one time instead of calling
gup N times.
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Add a helper to calculate the number of pages needed for a iov entry.
(nab: Drop unnecessary inline)
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This drops the cmd completion list spin lock and makes the cmd
completion queue lock-less.
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
It's OK to get kick before backend is set or after
it is cleared, we can just ignore it.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull target updates from Nicholas Bellinger:
"It has been a very busy development cycle this time around in target
land, with the highlights including:
- Kill struct se_subsystem_dev, in favor of direct se_device usage
(hch)
- Simplify reservations code by combining SPC-3 + SCSI-2 support for
virtual backends only (hch)
- Simplify ALUA code for virtual only backends, and remove left over
abstractions (hch)
- Pass sense_reason_t as return value for I/O submission path (hch)
- Refactor MODE_SENSE emulation to allow for easier addition of new
mode pages. (roland)
- Add emulation of MODE_SELECT (roland)
- Fix bug in handling of ExpStatSN wrap-around (steve)
- Fix bug in TMR ABORT_TASK lookup in qla2xxx target (steve)
- Add WRITE_SAME w/ UNMAP=0 support for IBLOCK backends (nab)
- Convert ib_srpt to use modern target_submit_cmd caller + drop
legacy ioctx->kref usage (nab)
- Convert ib_srpt to use modern target_submit_tmr caller (nab)
- Add link_magic for fabric allow_link destination target_items for
symlinks within target_core_fabric_configfs.c code (nab)
- Allocate pointers in instead of full structs for
config_group->default_groups (sebastian)
- Fix 32-bit highmem breakage for FILEIO (sebastian)
All told, hch was able to shave off another ~1K LOC by killing the
se_subsystem_dev abstraction, along with a number of PR + ALUA
simplifications. Also, a nice patch by Roland is the refactoring of
MODE_SENSE handling, along with the addition of initial MODE_SELECT
emulation support for virtual backends.
Sebastian found a long-standing issue wrt to allocation of full
config_group instead of pointers for config_group->default_group[]
setup in a number of areas, which ends up saving memory with big
configurations. He also managed to fix another long-standing BUG wrt
to broken 32-bit highmem support within the FILEIO backend driver.
Thank you again to everyone who contributed this round!"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (50 commits)
target/iscsi_target: Add NodeACL tags for initiator group support
target/tcm_fc: fix the lockdep warning due to inconsistent lock state
sbp-target: fix error path in sbp_make_tpg()
sbp-target: use simple assignment in tgt_agent_rw_agent_state()
iscsi-target: use kstrdup() for iscsi_param
target/file: merge fd_do_readv() and fd_do_writev()
target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
target: Add link_magic for fabric allow_link destination target_items
ib_srpt: Convert TMR path to target_submit_tmr
ib_srpt: Convert I/O path to target_submit_cmd + drop legacy ioctx->kref
target: Make spc_get_write_same_sectors return sector_t
target/configfs: use kmalloc() instead of kzalloc() for default groups
target/configfs: allocate only 6 slots for dev_cg->default_groups
target/configfs: allocate pointers instead of full struct for default_groups
target: update error handling for sbc_setup_write_same()
iscsit: use GFP_ATOMIC under spin lock
iscsi_target: Remove redundant null check before kfree
target/iblock: Forward declare bio helpers
target: Clean up flow in transport_check_aborted_status()
target: Clean up logic in transport_put_cmd()
...
Pull trivial branch from Jiri Kosina:
"Usual stuff -- comment/printk typo fixes, documentation updates, dead
code elimination."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
HOWTO: fix double words typo
x86 mtrr: fix comment typo in mtrr_bp_init
propagate name change to comments in kernel source
doc: Update the name of profiling based on sysfs
treewide: Fix typos in various drivers
treewide: Fix typos in various Kconfig
wireless: mwifiex: Fix typo in wireless/mwifiex driver
messages: i2o: Fix typo in messages/i2o
scripts/kernel-doc: check that non-void fcts describe their return value
Kernel-doc: Convention: Use a "Return" section to describe return values
radeon: Fix typo and copy/paste error in comments
doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
various: Fix spelling of "asynchronous" in comments.
Fix misspellings of "whether" in comments.
eisa: Fix spelling of "asynchronous".
various: Fix spelling of "registered" in comments.
doc: fix quite a few typos within Documentation
target: iscsi: fix comment typos in target/iscsi drivers
treewide: fix typo of "suport" in various comments and Kconfig
treewide: fix typo of "suppport" in various comments
...
The variable se_sess is initialized but never used
otherwise, so remove the unused variable.
dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vring changes already do a flush internally where appropriate, so we do
not need a second flush.
It's currently not very expensive but a follow-up patch makes flush more
heavy-weight, so remove the extra flush here to avoid regressing
performance if call or kick fds are changed on data path.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
linux/vhost.h was included twice.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values. This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.
(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Zerocopy handling code is vhost-net specific.
Move it from vhost.c/vhost.h out to net.c
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch converts tcm_vhost to use target_submit_cmd_map_sgls() for
I/O submission and mapping of pre-allocated SGL memory from incoming
virtio-scsi SGL memory -> se_cmd descriptors.
This includes removing the original open-coded fabric uses of target
core callers to support transport_generic_map_mem_to_cmd() between
target_setup_cmd_from_cdb() and transport_handle_cdb_direct() logic.
It also includes adding a handful of new tcm_vhost_cmnd member +
assignments in vhost_scsi_allocate_cmd() used from cmwq process
context I/O submission within tcm_vhost_submission_work()
(v2: Use renamed target_submit_cmd_map_sgls)
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Every fabric driver has to supply a se_tfo->set_fabric_sense_len()
method, just so iSCSI can return an offset of 2. However, every fabric
driver is already allocating a sense buffer and passing it into the
target core, either via transport_init_se_cmd() or target_submit_cmd().
So instead of having iSCSI pass the start of its sense buffer into the
core and then later tell the core to skip the first 2 bytes, it seems
easier for iSCSI just to do the offset of 2 when it passes the sense
buffer into the core. Then we can drop the se_tfo->set_fabric_sense_len()
everywhere, and just add a couple of lines of code to iSCSI to set the
sense data length to the beginning of the buffer right before it sends
it over the network.
(nab: Remove .set_fabric_sense_len usage from tcm_qla2xxx_npiv_ops +
change transport_get_sense_buffer to follow v3.6-rc6 code w/o
->set_fabric_sense_len usage)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
There are no callers of se_tfo->get_fabric_sense_len(), so we should
stop having every fabric driver implement it.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Here TRANSPORT_IQN_LEN is 224, which is a multiple of 4.
Since vhost_tpgt is 2 bytes and abi_version is 4, the total size would
be 230. But gcc needs struct size be aligned to first field size, which
is 4 bytes, so it pads the structure by extra 2 bytes to the total of
232.
This padding is very undesirable in an ABI:
- it can not be initialized easily
- it can not be checked easily
- it can leak information between kernel and userspace
Simplest solution is probably just to make the padding
explicit.
(v2: Add check for zero'ed backend->reserved field for VHOST_SCSI_SET_ENDPOINT
and VHOST_SCSI_CLEAR_ENDPOINT ops as requested by MST)
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the post RFC-v5 (post-merge) changes, this includes:
- Add locking comment
- Move vhost_scsi_complete_cmd ahead of TFO callbacks in order to
drop forward declarations
- Drop extra '!= NULL' usage in vhost_scsi_complete_cmd_work()
- Change vhost_scsi_*_handle_kick() to use pr_debug
- Fix possible race in vhost_scsi_set_endpoint() for vs->vs_tpg checking
+ assignment.
- Convert tv_tpg->tpg_vhost_count + ->tv_tpg_port_count from atomic_t ->
int, and make sure reference is protected by ->tv_tpg_mutex.
- Drop unnecessary vhost_scsi->vhost_ref_cnt
- Add 'err:' label for exception path in vhost_scsi_clear_endpoint()
- Add enum for VQ numbers, add usage in vhost_scsi_open()
- Add vhost_scsi_flush() + vhost_scsi_flush_vq() following
drivers/vhost/net.c
- Add smp_wmb() + vhost_scsi_flush() call during vhost_scsi_set_features()
- Drop unnecessary copy_from_user() usage with GET_ABI_VERSION ioctl
- Add missing vhost_scsi_compat_ioctl() caller for vhost_scsi_fops
- Fix function parameter definition first line to follow existing
vhost code style
- Change 'vHost' usage -> 'vhost' in handful of locations
- Change -EPERM -> -EBUSY usage for two failures in tcm_vhost_drop_nexus()
- Add comment for tcm_vhost_workqueue in tcm_vhost_init()
- Make GET_ABI_VERSION return 'int' + add comment in tcm_vhost.h
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds the initial code for tcm_vhost, a Vhost level TCM
fabric driver for virtio SCSI initiators into KVM guest.
This code is currently up and running on v3.5-rc2 host+guest
from target-pending/for-next-merge.
Using tcm_vhost requires Zhi's -> Stefan -> nab's qemu vhost-scsi tree here:
http://git.kernel.org/?p=virt/kvm/nab/qemu-kvm.git;a=shortlog;h=refs/heads/vhost-scsi
--
Changelog v4 -> v5:
Expose ABI version via VHOST_SCSI_GET_ABI_VERSION + use Rev 0 as
starting point for v3.6-rc code (Stefan + ALiguori + nab)
Convert vhost_scsi_handle_vq() to vq_err() (nab + MST)
Minor style fixes from checkpatch (nab)
Changelog v3 -> v4:
Rename vhost_vring_target -> vhost_scsi_target (mst + nab)
Use TRANSPORT_IQN_LEN in vhost_scsi_target->vhost_wwpn[] def (nab)
Move back to drivers/vhost/, and just use drivers/vhost/Kconfig.tcm (mst)
Move TCM_VHOST related ioctl defines from include/linux/vhost.h ->
drivers/vhost/tcm_vhost.h as requested by MST (nab)
Move Kbuild.tcm include from drivers/staging -> drivers/vhost/, and
just use 'if STAGING' around 'source drivers/vhost/Kbuild.tcm'
Changelog v2 -> v3:
Unlock on error in tcm_vhost_drop_nexus() (DanC)
Fix strlen() doesn't count the terminator (DanC)
Call kfree() on an error path (DanC)
Convert tcm_vhost_write_pending to use target_execute_cmd (hch + nab)
Fix another strlen() off by one in tcm_vhost_make_tport (DanC)
Add option under drivers/staging/Kconfig, and move to drivers/vhost/tcm/
as requested by MST (nab)
Changelog v1 -> v2:
Fix tv_cmd completion -> release SGL memory leak (nab)
Fix sparse warnings for static variable usage ((Fengguang Wu)
Fix sparse warnings for min() typing + printk format specs (Fengguang Wu)
Convert to cmwq submission for I/O dispatch (nab + hch)
Changelog v0 -> v1:
Merge into single source + header file, and move to drivers/vhost/
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
