Subject: add virtio disk geometry feature Date: Wed, 16 Apr 2008 13:56:37 -0500 From: Ryan Harper 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) --- drivers/block/virtio_blk.c | 24 ++++++++++++++++++++---- include/linux/virtio_blk.h | 7 +++++++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -157,10 +157,25 @@ static int virtblk_ioctl(struct inode *i /* We provide getgeo only to please some old bootloader/partitioning tools */ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) { - /* some standard values, similar to sd */ - geo->heads = 1 << 6; - geo->sectors = 1 << 5; - geo->cylinders = get_capacity(bd->bd_disk) >> 11; + struct virtio_blk *vblk = bd->bd_disk->private_data; + struct virtio_blk_geometry vgeo; + int err; + + /* see if the host passed in geometry config */ + err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY, + offsetof(struct virtio_blk_config, geometry), + &vgeo); + + if (!err) { + geo->heads = vgeo.heads; + geo->sectors = vgeo.sectors; + geo->cylinders = vgeo.cylinders; + } else { + /* some standard values, similar to sd */ + geo->heads = 1 << 6; + geo->sectors = 1 << 5; + geo->cylinders = get_capacity(bd->bd_disk) >> 11; + } return 0; } @@ -312,6 +327,7 @@ static struct virtio_device_id id_table[ static unsigned int features[] = { VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, + VIRTIO_BLK_F_GEOMETRY, }; static struct virtio_driver virtio_blk = { diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -9,6 +9,7 @@ #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ #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 /* Legacy geometry available */ struct virtio_blk_config { @@ -18,6 +19,12 @@ struct virtio_blk_config __le32 size_max; /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ __le32 seg_max; + /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ + struct virtio_blk_geometry { + __le16 cylinders; + __u8 heads; + __u8 sectors; + } geometry; } __attribute__((packed)); /* These two define direction. */