Re: [PATCH] nvme-pci: Use PCI bus address for data/queues in CMB

From: Keith Busch
Date: Tue Oct 03 2017 - 11:02:14 EST


On Sat, Sep 30, 2017 at 02:30:16PM +0530, Abhishek Shah wrote:
> > On a similar note, we also break CMB usage in virutalization with direct
> > assigned devices: the guest doesn't know the host physical bus address,
> > so it sets the CMB queue address incorrectly there, too. I don't know of
> > a way to fix that other than disabling CMB.
>
> I don't have much idea on CMB usage in virtualization... will let
> someone else comment on this.

It's okay, I think it's a gap in the NVMe specification that would allow
such usage.