> -----Original Message-----
> From: Jason Gunthorpe <[email protected]>
> Sent: 04 November 2025 15:13
> To: Shameer Kolothum <[email protected]>
> Cc: Eric Auger <[email protected]>; [email protected]; qemu-
> [email protected]; [email protected]; Nicolin Chen
> <[email protected]>; [email protected]; [email protected]; Nathan
> Chen <[email protected]>; Matt Ochs <[email protected]>;
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> Krishnakant Jaju <[email protected]>
> Subject: Re: [PATCH v5 15/32] hw/pci/pci: Introduce optional
> get_msi_address_space() callback
>
> On Tue, Nov 04, 2025 at 02:58:44PM +0000, Shameer Kolothum wrote:
> > > Sure it is trapped, but nothing should be looking at the MSI address
> > > from the guest, it is meaningless and wrong information. Just ignore
> > > it.
> >
> > Hmm.. we need to setup the doorbell address correctly.
>
> > If we don't do the translation here, it will use the Guest IOVA
> > address. Remember, we are using the IORT RMR identity mapping to get
> > MSI working.
>
> Either you use the RMR value, which is forced by the kernel into the
> physical MSI through iommufd and kernel ignores anything qemu
> does. So fully ignore the guest's vMSI address.
Well, we are sort of trying to do the same through this patch here.
But to avoid a "translation" completely it will involve some changes to
Qemu pci subsystem. I think this is the least intrusive path I can think
of now. And this is a one time setup mostly.
Thanks,
Shameer
