From 136be99e6e2130d3cd960b6b7d0ca86b6f011e5f Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 24 May 2012 13:22:55 +0200 Subject: 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 CC: Christoph Hellwig Reviewed-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- hw/virtio-blk.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 60750cb..fe07746 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -491,7 +491,22 @@ 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; -- cgit v1.1