diff options
author | Christian Borntraeger <borntraeger@de.ibm.com> | 2012-05-24 13:22:55 +0200 |
---|---|---|
committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2012-06-25 08:47:47 -0500 |
commit | c63c453889d0bfbd183da686bc076590220fd44a (patch) | |
tree | 725d0fa09299ad7dad5dbbbeb11e3a2fb28a7961 | |
parent | 78260a5f085d34e4ae46e42bdc010dfcd6f6cc31 (diff) |
virtio-blk: Fix geometry sector calculation
Currently the sector value for the geometry is masked, even if the
user usesa command line parameter that explicitely gives a number.
This breaks dasd devices on s390. A dasd device can have
a physical block size of 4096 (== same for logical block size)
and a typcial geometry of 15 heads and 12 sectors per cyl.
The ibm partition detection relies on a correct geometry
reported by the device. Unfortunately the current code changes
12 to 8. This would be necessary if the total size is
not a multiple of logical sector size, but for dasd this
is not the case.
This patch checks the device size and only applies sector
mask if necessary.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 136be99e6e2130d3cd960b6b7d0ca86b6f011e5f)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r-- | hw/virtio-blk.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index f9e1896ea..4f5745033 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -489,7 +489,22 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) stw_raw(&blkcfg.min_io_size, s->conf->min_io_size / blk_size); stw_raw(&blkcfg.opt_io_size, s->conf->opt_io_size / blk_size); blkcfg.heads = heads; - blkcfg.sectors = secs & ~s->sector_mask; + /* + * We must ensure that the block device capacity is a multiple of + * the logical block size. If that is not the case, lets use + * sector_mask to adopt the geometry to have a correct picture. + * For those devices where the capacity is ok for the given geometry + * we dont touch the sector value of the geometry, since some devices + * (like s390 dasd) need a specific value. Here the capacity is already + * cyls*heads*secs*blk_size and the sector value is not block size + * divided by 512 - instead it is the amount of blk_size blocks + * per track (cylinder). + */ + if (bdrv_getlength(s->bs) / heads / secs % blk_size) { + blkcfg.sectors = secs & ~s->sector_mask; + } else { + blkcfg.sectors = secs; + } blkcfg.size_max = 0; blkcfg.physical_block_exp = get_physical_block_exp(s->conf); blkcfg.alignment_offset = 0; |