virtio-blk: add SGI_IO passthru support

[had the qemu list address wrong the first time, reply to this message,
 not the previous if you were on Cc]

Add support for SG_IO passthru (packet commands) to the virtio-blk
backend.  Conceptually based on an older patch from Hannes Reinecke
but largely rewritten to match the code structure and layering in
virtio-blk.

Note that currently we issue the hose SG_IO synchronously.  We could
easily switch to async I/O, but that would required either bloating
the VirtIOBlockReq by the size of struct sg_io_hdr or an additional
memory allocation for each SG_IO request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Christoph Hellwig 2009-04-27 10:29:14 +02:00 committed by Anthony Liguori
parent 451c4abd8c
commit 1063b8b15f
2 changed files with 128 additions and 7 deletions

View file

@ -28,6 +28,9 @@
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
#define VIRTIO_BLK_F_GEOMETRY 4 /* Indicates support of legacy geometry */
#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
struct virtio_blk_config
{
@ -70,6 +73,15 @@ struct virtio_blk_inhdr
unsigned char status;
};
/* SCSI pass-through header */
struct virtio_scsi_inhdr
{
uint32_t errors;
uint32_t data_len;
uint32_t sense_len;
uint32_t residual;
};
void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs);
#endif