Re: [Qemu-devel] [PATCH] virtio-scsi spec: add per-LUN parameter query

[Paolo Bonzini <pbonzini@redhat.com>]

Il 20/08/2012 11:03, Cong Meng ha scritto:
> Each virtio scsi HBA has global request queue limits. But the passthrough
> LUNs (scsi-generic) come from different host HBAs may have different request
> queue limits. If the guest sends commands that exceed the host limits, the
> commands will be rejected by host HAB. 
> 
> To address this issue, this patch adds a per-LUN parameter query via the control
> queue, and defines some parameter query types. The driver can query and set the
> needed per-LUN parameters if the device enables this feature.
> 
> Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com>
> --
>  virtio-spec.lyx |  218 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 218 insertions(+), 0 deletions(-)

Do you have kernel and QEMU patches for this?  That would help me
evaluate whether the interface is the correct one.

In any case, I'd rather have a single command returning all three values
(VIRTIO_SCSI_T_LUN_QUEUE_PARAMS), since it's unlikely that you need just
one.

Paolo