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 136be99e6e
)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
parent
78260a5f08
commit
c63c453889
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@ -489,7 +489,22 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
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stw_raw(&blkcfg.min_io_size, s->conf->min_io_size / blk_size);
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stw_raw(&blkcfg.opt_io_size, s->conf->opt_io_size / blk_size);
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blkcfg.heads = heads;
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blkcfg.sectors = secs & ~s->sector_mask;
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/*
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* We must ensure that the block device capacity is a multiple of
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* the logical block size. If that is not the case, lets use
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* sector_mask to adopt the geometry to have a correct picture.
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* For those devices where the capacity is ok for the given geometry
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* we dont touch the sector value of the geometry, since some devices
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* (like s390 dasd) need a specific value. Here the capacity is already
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* cyls*heads*secs*blk_size and the sector value is not block size
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* divided by 512 - instead it is the amount of blk_size blocks
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* per track (cylinder).
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*/
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if (bdrv_getlength(s->bs) / heads / secs % blk_size) {
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blkcfg.sectors = secs & ~s->sector_mask;
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} else {
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blkcfg.sectors = secs;
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}
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blkcfg.size_max = 0;
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blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
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blkcfg.alignment_offset = 0;
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