linux/drivers/vhost
Greg Kurz 2751c9882b vhost: cross-endian support for legacy devices
This patch brings cross-endian support to vhost when used to implement
legacy virtio devices. Since it is a relatively rare situation, the
feature availability is controlled by a kernel config option (not set
by default).

The vq->is_le boolean field is added to cache the endianness to be
used for ring accesses. It defaults to native endian, as expected
by legacy virtio devices. When the ring gets active, we force little
endian if the device is modern. When the ring is deactivated, we
revert to the native endian default.

If cross-endian was compiled in, a vq->user_be boolean field is added
so that userspace may request a specific endianness. This field is
used to override the default when activating the ring of a legacy
device. It has no effect on modern devices.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2015-06-01 15:48:55 +02:00
..
Kconfig vhost: cross-endian support for legacy devices 2015-06-01 15:48:55 +02:00
Makefile vhost: Make vhost a separate module 2013-07-07 17:33:44 +03:00
net.c new helper: msg_data_left() 2015-04-11 15:53:35 -04:00
scsi.c target: Fix se_tpg_tfo->tf_subsys regression + remove tf_subsystem 2015-05-30 18:04:20 -07:00
test.c vhost: move memory pointer to VQs 2014-06-09 16:21:07 +03:00
test.h vhost test module 2010-12-09 16:00:21 +02:00
vhost.c vhost: cross-endian support for legacy devices 2015-06-01 15:48:55 +02:00
vhost.h vhost: cross-endian support for legacy devices 2015-06-01 15:48:55 +02:00
vringh.c vringh: update for virtio 1.0 APIs 2014-12-15 23:49:28 +02:00