Re: [Xen-devel] Is: 'basic pci bridge and root device support. 'Was:Re: Discussion about virtual iommu support for Xen guest

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Mon, Jun 06, 2016 at 03:55:06AM -0600, Jan Beulich wrote:
> >>> On 03.06.16 at 21:51, <konrad.wilk@xxxxxxxxxx> wrote:
> >>  For HVMLite, there is specifically no qemu, and we need something which
> >> can function when we want PCI Passthrough to work.  I am quite confident
> >> that the correct solution here is to have a basic host bridge/root port
> >> implementation in Xen (as we already have 80% of this already), at which
> >> point we don't need any qemu interaction for PCI Passthough at all, even
> >> for HVM guests.
> > 
> > Could you expand on this a bit?
> > 
> > I am asking b/c some time ago I wrote in Xen code to construct a full view
> > of the bridges->devices (and various in branching) so that I could renumber
> > the bus values and its devices (expand them) on bridges. This was solely 
> > done
> > so that I could use SR-IOV devices on non-SR-IOV capable BIOSes.
> > 
> > I am wondering how much of the basic functionality (enumeration, keeping
> > track, etc) could be worked in this 'basic host bridge/root port' 
> > implementation
> > idea of yours.
> 
> Keep in mind that your work was for the host's PCI, while here
> we're talking about the guest's.

Right, but some of this accounting code could be added in Xen to help
with keeping track of physical vs virtual layouts.

> 
> Jan
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel