Commit Graph

6 Commits

Author SHA1 Message Date
Wei Liu
ccc9d90a9a xenbus_client: Extend interface to support multi-page ring
Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-15 10:56:47 +01:00
Juergen Gross
85617dc7ee xen: support suspend/resume in pvscsi frontend
Up to now the pvscsi frontend hasn't supported domain suspend and
resume. When a domain with an assigned pvscsi device was suspended
and resumed again, it was not able to use the device any more: trying
to do so resulted in hanging processes.

Support suspend and resume of pvscsi devices.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-03-16 14:49:15 +00:00
David Vrabel
95afae4814 xen: remove DEFINE_XENBUS_DRIVER() macro
The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.

Replace the uses with standard structure definitions instead.  This is
similar to pci and usb device registration.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-10-06 10:27:57 +01:00
David Vrabel
7921a11c7b xen-scsifront: don't deadlock if the ring becomes full
scsifront_action_handler() will deadlock on host->host_lock, if the
ring is full and it has to wait for entries to become available.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2014-10-03 12:34:40 +01:00
Dan Carpenter
d9b1e6374b xen-scsifront: use GFP_ATOMIC under spin_lock
This function is only called with a spin_lock held and IRQs disabled.
The allocation is not allowed to sleep and NOIO is not sufficient, it
has to be ATOMIC.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-09-23 13:36:19 +00:00
Juergen Gross
8beb8d4c91 xen-scsifront: Add Xen PV SCSI frontend driver
Introduces the Xen pvSCSI frontend. With pvSCSI it is possible for a
Xen domU to issue SCSI commands to a SCSI LUN assigned to that
domU. The SCSI commands are passed to the pvSCSI backend in a driver
domain (usually Dom0) which is owner of the physical device. This
allows e.g. to use SCSI tape drives in a Xen domU.

The code is taken from the pvSCSI implementation in Xen done by
Fujitsu based on Linux kernel 2.6.18.

Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- move module to appropriate location in kernel tree
- adapt to Linux style guide
- some minor code simplifications
- replace constants with defines
- remove not used defines
- add support for larger SG lists by putting them in a granted page

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-09-23 13:36:19 +00:00