Messages in this thread | | | Date | Mon, 16 Jan 2017 15:17:59 -0500 (EST) | From | Paolo Bonzini <> | Subject | Re: [PATCH 0/2] virtio-scsi: Implement FC_HOST feature |
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> 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 is taken care of in the host by presenting to the host all LUNs from a host's NPIV vHBA. (Libvirt probably would be the one taking care of this, because QEMU may not have enough permissions).
> 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?
I'm not sure I understand.
Neither I nor Fam know this stuff very well, but we are trying to do the same as Hyper-V (and other proprietary hypervisors too).
> 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?
Is this your old idea of adding a separate target field to commands, in order to support 64-bit LUNs? That is separate, and most FC drivers only default to 16-bit LUNs anyway.
> And we really should make sure to have a single FC host in the guest > presenting all LUNs.
Yes, of course.
Paolo
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