linux-toradex.git/include/linux/virtio_config.h, branch v2.6.31.2

lguest and virtio: cleanup struct definitions to Linux style.

2009-07-30T06:33:46+00:00

I've been doing this for years, and akpm picked me up on it about 12
months ago.  lguest partly serves as example code, so let's do it Right.

Also, remove two unused fields in struct vblk_info in the example launcher.

Signed-off-by: Rusty Russell 
Cc: Ingo Molnar

virtio: teach virtio_has_feature() about transport features

2009-06-12T12:46:38+00:00

Drivers don't add transport features to their table, so we
shouldn't check these with virtio_check_driver_offered_feature().

We could perhaps add an ->offered_feature() virtio_config_op,
but that perhaps that would be overkill for a consitency check
like this.

Signed-off-by: Mark McLoughlin 
Signed-off-by: Rusty Russell

virtio: find_vqs/del_vqs virtio operations

2009-06-12T12:46:36+00:00

This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Rusty Russell  (+ lguest/9p compile fixes)

virtio: add names to virtqueue struct, mapping from devices to queues.

2009-06-12T12:46:36+00:00

Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.

Signed-off-by: Rusty Russell

virtio: Rename set_features to finalize_features

2008-07-25T02:06:12+00:00

Rather than explicitly handing the features to the lower-level, we just
hand the virtio_device and have it set the features.  This make it clear
that it has the chance to manipulate the features of the device at this
point (and that all feature negotiation is already done).

Signed-off-by: Rusty Russell

virtio: Formally reserve bits 28-31 to be 'transport' features.

2008-07-25T02:06:07+00:00

We assign feature bits as required, but it makes sense to reserve some
for the particular transport, rather than the particular device.

Signed-off-by: Rusty Russell

virtio: clarify that ABI is usable by any implementations

2008-07-25T02:06:04+00:00

We want others to implement and use virtio, so it makes sense to BSD
license the non-__KERNEL__ parts of the headers to make this crystal
clear.

Signed-off-by: Rusty Russell 
Acked-by: Christian Borntraeger 
Acked-by: Mark McLoughlin 
Acked-by: Ryan Harper 
Acked-by: Eric Van Hensbergen 
Acked-by: Anthony Liguori

virtio: force callback on empty.

2008-05-30T05:09:46+00:00

virtio allows drivers to suppress callbacks (ie. interrupts) for
efficiency (no locking, it's just an optimization).

There's a similar mechanism for the host to suppress notifications
coming from the guest: in that case, we ignore the suppression if the
ring is completely full.

It turns out that life is simpler if the host similarly ignores
callback suppression when the ring is completely empty: the network
driver wants to free up old packets in a timely manner, and otherwise
has to use a timer to poll.

We have to remove the code which ignores interrupts when the driver
has disabled them (again, it had no locking and hence was unreliable
anyway).

Signed-off-by: Rusty Russell

virtio_config: fix len calculation of config elements

2008-05-30T05:09:45+00:00

Rusty,

This patch is a prereq for the virtio_blk blocksize patch, please apply it
first.

Adding an u32 value to the virtio_blk_config unconvered a small bug the config
space defintions:
v is a pointer, to we have to use sizeof(*v) instead of sizeof(v).

Signed-off-by: Christian Borntraeger 
Signed-off-by: Rusty Russell

virtio: explicit advertisement of driver features

2008-05-02T11:50:50+00:00

A recent proposed feature addition to the virtio block driver revealed
some flaws in the API: in particular, we assume that feature
negotiation is complete once a driver's probe function returns.

There is nothing in the API to require this, however, and even I
didn't notice when it was violated.

So instead, we require the driver to specify what features it supports
in a table, we can then move the feature negotiation into the virtio
core.  The intersection of device and driver features are presented in
a new 'features' bitmap in the struct virtio_device.

Note that this highlights the difference between Linux unsigned-long
bitmaps where each unsigned long is in native endian, and a
straight-forward little-endian array of bytes.

Drivers can still remove feature bits in their probe routine if they
really have to.

API changes:
- dev->config->feature() no longer gets and acks a feature.
- drivers should advertise their features in the 'feature_table' field
- use virtio_has_feature() for extra sanity when checking feature bits

Signed-off-by: Rusty Russell