Mini-OS and force_evtchn_callback()

Mini-OS and force_evtchn_callback()

[Simon Kagstrom]

Hello!

I'm trying to understand the event channel handling more in detail, and was
playing around a bit with the Mini-OS. However, it does not behave quite as
I had expected.

After having done a sti(), I do a force_evtchn_callback() which I though would
cause an event to be sent to hypervisor_callback(), which was registered as
the channel callback with HYPERVISOR_set_callacks().

The callback is not called until the domain issues a HYPERVISOR_set_timer_op() and
thereafter blocks with HYPERVISOR_sched_op(). Is this the expected behavior,
or is there something wrong with the Mini-OS or did I simply miss something?

-- 
// Simon

Re: Mini-OS and force_evtchn_callback()

[Keir Fraser]

On 27 Jan 2006, at 14:27, Simon Kagstrom wrote:

> I'm trying to understand the event channel handling more in detail, 
> and was
> playing around a bit with the Mini-OS. However, it does not behave 
> quite as
> I had expected.
>
> After having done a sti(), I do a force_evtchn_callback() which I 
> though would
> cause an event to be sent to hypervisor_callback(), which was 
> registered as
> the channel callback with HYPERVISOR_set_callacks().

It'll only force a callback if an event is pending.

  -- Keir

Re: Mini-OS and force_evtchn_callback()

[Simon Kagstrom]

On 2006-01-27, 14:41, Keir Fraser wrote:
> 
> On 27 Jan 2006, at 14:27, Simon Kagstrom wrote:
> 
> >After having done a sti(), I do a force_evtchn_callback() which I though
> >would cause an event to be sent to hypervisor_callback(), which was
> >registered as the channel callback with HYPERVISOR_set_callacks().
> 
> It'll only force a callback if an event is pending.

Is it possible to insert an event through e.g., xm on dom0?

-- 
// Simon

Re: Mini-OS and force_evtchn_callback()

[Keir Fraser]

On 30 Jan 2006, at 08:53, Simon Kagstrom wrote:

>> It'll only force a callback if an event is pending.
>
> Is it possible to insert an event through e.g., xm on dom0?

You have console and xenstore event channels set up for you. You can 
unmask those in the mini-os and then trigger them in dom0, sure.

  -- Keir