On Thu, Sep 04, 2014 at 02:28:26PM +0400, Ekaterina Tumanova wrote: > On 09/03/2014 07:46 PM, Stefan Hajnoczi wrote: > >On Tue, Jul 29, 2014 at 02:27:19PM +0200, Ekaterina Tumanova wrote: > >>This patch add the blkconf_blocksize call to all > >>devices, which use DEFINE_BLOCK_PROPERTIES. > >>If the underlying driver function fails, blkconf_blocksizes > >>will set blocksizes to default (512) value. > >> > >>Signed-off-by: Ekaterina Tumanova <tuman...@linux.vnet.ibm.com> > >>Reviewed-by: David Hildenbrand <d...@linux.vnet.ibm.com> > >>Acked-by: Cornelia Huck <cornelia.h...@de.ibm.com> > >>--- > >> hw/block/nvme.c | 1 + > >> hw/block/virtio-blk.c | 1 + > >> hw/ide/qdev.c | 1 + > >> hw/scsi/scsi-disk.c | 1 + > >> hw/usb/dev-storage.c | 1 + > >> include/hw/block/block.h | 4 ++-- > >> 6 files changed, 7 insertions(+), 2 deletions(-) > > > >Wasn't this NACKed before on the grounds that it is likely to upset the > >guest after live migration? QEMU doesn't automatically query the > >storage because these parameters must be preserved across migration. > > > > Sorry, haven't found this discussion in the mail list. Do you have a link?
I don't have the link but am referring to the last time these patches were discussed - ~1 year ago? > As far as I understand, the xxxxxx_init functions of the qemu block devices, > which contain blkconf_blocksize calls, will > be called again on the destination host before the guest is resumed. And > since migration requests qemu to be brought on the same disk, the > configuration will receive the same block size from the ioctl, as > before. What do I miss? Live storage migration is supported. This means non-shared storage is possible. Therefore the host block device that a guest runs on can change. > >If you want specific parameters, please put them in your guest > >configuration. QEMU and libvirt support that. > > > >I'm concerned that this patch serious is likely to break things and > >autodetection doesn't add much value since the management tool needs to > >be aware of this information anyway. > > > > Can you please explain what do you mean by "AUTOdetection"? > Do you simply mean "detection by ioctl" or "detection performed without > guest request"? I mean passing through the host block device attributes to the guest. Stefan
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