Re: VIRTIO - compatibility with different virtualization solutions

[Rusty Russell <rusty@au1.ibm.com>]

Daniel Kiper <daniel.kiper@oracle.com> writes:
> Hi,
>
> Below you could find a summary of work in regards to VIRTIO compatibility with
> different virtualization solutions. It was done mainly from Xen point of view
> but results are quite generic and can be applied to wide spectrum
> of virtualization platforms.

Hi Daniel,

        Sorry for the delayed response, I was pondering...  CC changed
to virtio-dev.

From a standard POV: It's possible to abstract out the where we use
'physical address' for 'address handle'.  It's also possible to define
this per-platform (ie. Xen-PV vs everyone else).  This is sane, since
Xen-PV is a distinct platform from x86.

For platforms using EPT, I don't think you want anything but guest
addresses, do you?

From an implementation POV:

On IOMMU, start here for previous Linux discussion:
        http://thread.gmane.org/gmane.linux.kernel.virtualization/14410/focus=14650

And this is the real problem.  We don't want to use the PCI IOMMU for
PCI devices.  So it's not just a matter of using existing Linux APIs.

Cheers,
Rusty.