linux/drivers/virtio, branch v2.6.24

virtio: fix module/device unloading

2007-11-19T00:20:42Z

The virtio code never hooked through the ->remove callback. Although noone supports device removal at the moment, this code is already needed for module unloading. This of course also revealed bugs in virtio_blk, virtio_net and lguest unloading paths. Signed-off-by: Rusty Russell

virtio: Force use of power-of-two for descriptor ring sizes

2007-11-12T02:59:40Z

The virtio descriptor rings of size N-1 were nicely set up to be aligned to an N-byte boundary. But as Anthony Liguori points out, the free-running indices used by virtio require that the sizes be a power of 2, otherwise we get problems on wrap (demonstrated with lguest). So we replace the clever "2^n-1" scheme with a simple "align to page boundary" scheme: this means that all virtio rings take at least two pages, but it's safer than guessing cache alignment. Signed-off-by: Rusty Russell

virtio: Fix used_idx wrap-around

2007-11-12T02:59:09Z

The more_used() function compares the vq->vring.used->idx with last_used_idx. Since vq->vring.used->idx is a 16-bit integer, and last_used_idx is an unsigned int, this results in unpredictable behavior when vq->vring.used->idx wraps around. This patch corrects this by changing last_used_idx to the correct type. Signed-off-by: Anthony Liguori Signed-off-by: Rusty Russell

Virtio helper routines for a descriptor ringbuffer implementation

2007-10-23T05:49:55Z

These helper routines supply most of the virtqueue_ops for hypervisors which want to use a ring for virtio. Unlike the previous lguest implementation: 1) The rings are variable sized (2^n-1 elements). 2) They have an unfortunate limit of 65535 bytes per sg element. 3) The page numbers are always 64 bit (PAE anyone?) 4) They no longer place used[] on a separate page, just a separate cacheline. 5) We do a modulo on a variable. We could be tricky if we cared. 6) Interrupts and notifies are suppressed using flags within the rings. Users need only get the ring pages and provide a notify hook (KVM wants the guest to allocate the rings, lguest does it sanely). Signed-off-by: Rusty Russell Cc: Dor Laor

Module autoprobing support for virtio drivers.

2007-10-23T05:49:55Z

This adds the logic to convert the virtio ids into module aliases, and includes a modalias entry in sysfs and the env var to make probing work. Signed-off-by: Rusty Russell

Virtio interface

2007-10-23T05:49:54Z

This attempts to implement a "virtual I/O" layer which should allow common drivers to be efficiently used across most virtual I/O mechanisms. It will no-doubt need further enhancement. The virtio drivers add buffers to virtio queues; as the buffers are consumed the driver "interrupt" callbacks are invoked. There is also a generic implementation of config space which drivers can query to get setup information from the host. Signed-off-by: Rusty Russell Cc: Dor Laor Cc: Arnd Bergmann