Re: Design doc of adding ACPI support for arm64 on Xen - version 4

["Roger Pau Monné" <roger.pau@citrix.com>]

El 19/08/15 a les 14.13, Shannon Zhao ha escrit:
> 4. Map MMIO regions
> -------------------
> Register a bus_notifier for platform and amba bus in Linux. Add a new

Can we make this OS agnostic? Could you explain what you mean with the
above sentence without using Linux kernel internals?

> XENMAPSPACE "XENMAPSPACE_dev_mmio". The usage of this hypercall
> parameters:
> - domid: DOMID_SELF.
> - space: XENMAPSPACE_dev_mmio.
> - gpfns: guest physical addresses where the mapping should appear.

This is not complete, you have forgotten to add the idxs field, and I
don't think the domid field needs an explanation TBH.

>
> Within the register, check if the device is newly added, then call
> hypercall XENMEM_add_to_physmap to map the mmio regions.
>
> For PCI bus device, it could reuse the existing PCI bus_notifier like
> X86.

What is a PCI bus_notifier? I don't see any mention of bus_notifier in
Xen code.

In general the text above seems more like a description of the Linux
implementation rather than a Xen design document. Could you explain
without using Linux internals how/when this new hypercall should be used?

If you want you can provide examples about how this new interface is
going to be used in Linux, but the general description should remain OS
agnostic IMHO.

Roger.