linux-toradex.git/include/linux/virtio_blk.h, branch v2.6.27.31

virtio_blk: check for hardsector size from host

2008-07-25T02:06:05+00:00

Currently virtio_blk assumes a 512 byte hard sector size. This can cause
trouble / performance issues if the backing has a different block size
(like a file on an ext3 file system formatted with 4k block size or a dasd).

Lets add a feature flag that tells the guest to use a different hard sector
size than 512 byte.

Signed-off-by: Christian Borntraeger 
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_blk: fix endianess annotations

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

Since commit 72e61eb40b55dd57031ec5971e810649f82b0259 (virtio: change config
to guest endian) config space is no longer fixed endian.

Lets change the virtio_blk_config variables.

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

virtio_blk: allow read-only disks

2008-05-30T05:09:44+00:00

Hello Rusty,

sometimes it is useful to share a disk (e.g. usr). To avoid file system
corruption, the disk should be mounted read-only in that case. This patch
adds a new feature flag, that allows the host to specify, if the disk should
be considered read-only.

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

virtio: add virtio disk geometry feature

2008-05-02T11:50:51+00:00

Rather than faking up some geometry, allow the backend to push the disk
geometry via virtio pci config option.  Keep the old geo code around for
compatibility.

Signed-off-by: Ryan Harper 
Reviewed-by: Anthony Liguori 
Signed-off-by: Rusty Russell  (modified to single struct)

virtio: de-structify virtio_block status byte

2008-05-02T11:50:45+00:00

Ron Minnich points out that a struct containing a char is not always
sizeof(char); simplest to remove the structure to avoid confusion.

Cc: "ron minnich" 

Signed-off-by: Rusty Russell

virtio: remove unused id field from struct virtio_blk_outhdr

2008-02-04T12:50:01+00:00

This field has been unused since an older version of virtio.  Remove
it now before we freeze the ABI.

Signed-off-by: Rusty Russell

virtio: simplify config mechanism.

2008-02-04T12:49:57+00:00

Previously we used a type/len pair within the config space, but this
seems overkill.  We now simply define a structure which represents the
layout in the config space: the config space can now only be extended
at the end.

The main driver-visible changes:
1) We indicate what fields are present with an explicit feature bit.
2) Virtqueues are explicitly numbered, and not in the config space.

Signed-off-by: Rusty Russell

Block driver using virtio.

2007-10-23T05:49:54+00:00

The block driver uses scatter-gather lists with sg[0] being the
request information (struct virtio_blk_outhdr) with the type, sector
and inbuf id.  The next N sg entries are the bio itself, then the last
sg is the status byte.  Whether the N entries are in or out depends on
whether it's a read or a write.

We accept the normal (SCSI) ioctls: they get handed through to the other
side which can then handle it or reply that it's unsupported.  It's
not clear that this actually works in general, since I don't know
if blk_pc_request() requests have an accurate rq_data_dir().

Although we try to reply -ENOTTY on unsupported commands, ioctl(fd,
CDROMEJECT) returns success to userspace.  This needs a separate
patch.

Signed-off-by: Rusty Russell 
Cc: Jens Axboe