Rusty,
I currently try to make my guest boot from an virtio root device
without having an external kernel. Some of the tools that I tried
expect HDIO_GETGEO to work. The most interesting value is likely
the geo.start value to get the offset of a partition. This value
is filled by block/ioctl.c if fops->getgeo is set. This patch also
fills in some standard values for heads, sectors and cylinders.
Makes sense?
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
drivers/block/virtio_blk.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
Index: kvm/drivers/block/virtio_blk.c
===================================================================
--- kvm.orig/drivers/block/virtio_blk.c
+++ kvm/drivers/block/virtio_blk.c
@@ -154,9 +154,20 @@ static int virtblk_ioctl(struct inode *i
(void __user *)data);
}
+/* 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;
+ return 0;
+}
+
static struct block_device_operations virtblk_fops = {
- .ioctl = virtblk_ioctl,
- .owner = THIS_MODULE,
+ .ioctl = virtblk_ioctl,
+ .owner = THIS_MODULE,
+ .getgeo = virtblk_getgeo,
};
static int virtblk_probe(struct virtio_device *vdev)
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