Commit Graph

9 Commits

Author SHA1 Message Date
Dariusz Stojaczyk
6ccc262022 virtio: remove g_virtio_driver
g_virtio_driver contained just a list of all
Virtio-SCSI devices. It's now being removed for
two reasons:
 * it's backend-specific, doesn't fit a generic virtio lib
 * it's difficult to ensure thread-safety for it

Virtio bdev modules will now manage their Virtio
devices by themselves. Virtio-SCSI has now an internal
device list. (And VirtioBlk module maps devices to
bdevs 1:1, so doesn't need any additional work here.)

Change-Id: I3bc68d76d6904df5c56f00fca7ab387871ecf88f
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/405179
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
2018-03-27 00:58:14 -04:00
Dariusz Stojaczyk
face9eb258 virtio: add mb() before checking notify flag
The kernel vhost target enables notifying after processing
each interrupt in a following manner.

 * unset NO_NOTIFY flag
 * mb()
 * check avail ring for slipped requests

And we do the following after issuing each I/O.

 * update avail ring
 * check NO_NOTIFY

If NO_NOTIFY check is reordered and read first, we might read
old `true` value, and avail ring might be updated after the
kernel has already done its check. This easily leads to deadlock.

Change-Id: I6bb4490775dfed6fb2987e97c39b713054ae26ad
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/396499
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
2018-02-06 19:27:46 -05:00
Dariusz Stojaczyk
5926647156 virtio: inline internal functions
These didn't make much sense anyway.
Removed them so there's less code

Change-Id: I3247c640b13e5847b5f6d822072b63cad269ac8c
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/398467
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
2018-02-06 19:27:46 -05:00
Dariusz Stojaczyk
7f0c2bf4b4 virtio: remove virtio_dev_get_status asserts
virtio_dev_get_status may result in an MMIO read,
which is quite expensive. Removed it to improve
performance on debug builds.

Change-Id: Ibe2d13ad381f02f8d258d630283c14ce20b7a340
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/398468
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2018-02-05 19:06:11 -05:00
Dariusz Stojaczyk
fb12bbecd2 virtio: move vdev->name allocation to generic virtio
Previously vdev->name was being allocated/freed
separately in virtio_pci and virtio_user backends.
Now it's all done in generic virtio library and
cleans up some code.

Change-Id: I810e976d09781c0c9b25c6f7fd957a83aad6c7b8
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/394704
Reviewed-by: <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2018-01-23 22:49:21 -05:00
Dariusz Stojaczyk
8b94174a4e virtio: fix full-virtqueue handling
Distinguish between "not enough descriptors available"
and "iovcnt > queue depth".

This patch brings back I/O re-queueing for virtio bdev
module. It was temporarily disabled by 451de7e1 [1].

[1] 451de7e1: "virtio: switch to the new virtqueue API"

Change-Id: I4c4f6a6d9d91373ee647ea7cafd53ad999aa6aa2
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/393447
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2018-01-03 14:35:36 -05:00
Dariusz Stojaczyk
7755bed389 virtio: split device initialization to separate functions
Previously we used to manually set
vdev->max_queues and called virtio_dev_restart
to go through all virtio init states, negotiate
features and allocate virtqueues. This is,
however, insufficient for Virtio-Blk, where we
e.g. need to check against negotiated multiqueue
flag before deciding how many queues we can use
(reading num_queues field from device config is
forbidden unless VIRTIO_BLK_F_MQ is negotiated).

This patch refactors queue-num related code
and also removes various restrictions. If device
supports less queues than requested, a warning
will be printed during initialization, but
the device will now continue to init normally.

The queue-num negotiation for virtio-user should
be eventually moved to upper layers, but that is
not necessary for now.

Change-Id: I418b56fa62c17b547243422ea077f0d76555bd13
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/393087
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-27 15:13:03 -05:00
Dariusz Stojaczyk
a1ca7a12ff virtio: fix enqueuing zero-length descriptor chains
Previous descriptor chain was being corrupted
by setting invalid vq->req_end (virtio.c:538).

Change-Id: I4b27db02dc990e6af011a1b614e30e3050379e9f
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/392774
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-27 15:13:03 -05:00
Dariusz Stojaczyk
9dde5e5c27 virtio: add new library virtio
Exported lib/bdev/rte_virtio as a separate
library not dependent on bdev.

Virtio is now accessible via spdk_internal/virtio.h.
The header is marked `internal`, as it's
not meant to be used by end users. It's
not handy to handle all backend-specific
(e.g. Virtio-SCSI) logic in a user code.

For now the Virtio interface is publicly
exposed only via bdev_virtio module. We
might want to consider adding a separate,
public Virtio-SCSI library in the future.

Note: this patch doesn't do any changes
to the virtio code. Everything is
moved 1:1.

Change-Id: I805e5d12d265d82b0bc5784c89fbadb81abdb278
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/388166
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-26 13:03:29 -05:00