On 01/16/2017 05:04 PM, Fam Zheng wrote: > This series implements the proposed fc_host feature of virtio-scsi. > > The first patch updates the data structure changes according to the spec > proposal; the second patch actually implements the operations. > > Fam Zheng (2): > virtio_scsi: Add fc_host definitions > virtio_scsi: Implement fc_host > > drivers/scsi/virtio_scsi.c | 55 +++++++++++++++++++++++++++++++++++++++- > include/uapi/linux/virtio_scsi.h | 6 +++++ > 2 files changed, 60 insertions(+), 1 deletion(-) > Hmm. How it this supposed to work? You do export the WWPN/WWNN of the associated host to the guest (nb: will get interesting for non NPIV setups ...), but virtio scsi will still do a LUN remapping. IE the LUNs you see on the host will be different from the LUNs presented to the guest. This makes reliable operations very tricky. Plus you don't _actually_ expose the FC host, but rather the WWPN of the host presenting the LUN. So how do you handle LUNs from different FC hosts on the guest? >From what I've seen virtio will either presenting you with with one host per LUN (so you'll end up with different SCSI hosts on the guest each having the _same_ WWPN/WWNN), or a single host presenting all LUNs, making the WWPN setting ... interesting. Overall, I'm not overly happy with this approach. You already added WWPN ids to the virtio transport, so why didn't you update the LUN field, too, to avoid this ominous LUN remapping? And we really should make sure to have a single FC host in the guest presenting all LUNs. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
