Re: [Xen-devel] [RFC/WIP] xen: clk: introudce pvclk for device passthrough

[George Dunlap]

On Sat, Jan 16, 2016 at 5:22 AM, Peng Fan <van.freenix@xxxxxxxxx> wrote:
> This patch was just a initial patch, not sure whether this way
> is ok from you side for handlding clk when doing platform device
> passhthrough. Any comments are appreciated, and your comments may
> give me a better direction.

Hey Peng,

Just speaking from the perspective of a Xen dev who's not an ARM dev:
a few more words on the relationship between pvclk and
device-passthrough would be helpful to set the context.  It sounds
like:

* On ARM, passing through a device requires a clocksource (at least
for many devices)

* dom0 has the hardware clocksource, but at the moment domUs don't
have a suitable clocksource

* This patch implements pvclk front/backend suitable for such devices

Is that right?  In which case something like the following would be helpful:

"This patch introduces pvclk, a paravirtualized clock source suitable
for devices to use when passing through to domUs on ARM systems."

(Obviously change it as necessary to make it accurate.)

Thanks,
 -George