Re: [PATCH] interrupt preemption support

Avi Kivity
2007-03-19T14:00:51Z

Gregory Haskins wrote:
> Hi Avi,
> You make good points. I will convert to a nest lock design and resubmit. Should I use two mutexes, or a mutex and spinlock?
>
> Also, do you have any suggestions on the signum I should use to IPI the running guest? Should I use one of the normal signals (SIGUSR) or should I start a block of defined signals in the RT range (>32)?
>

For a short term solution, where the apic is in userspace, we can just
say ipi == signal, and not require any locking. Qemu will catch the
signal and call the appropriate apic function. The signal number should
be set from userspace.

Longer term, with the apic in the kernel, we'll need to protect the
apic/interrupt data structures with a spinlock, and use kick_process()
or similar instead of a signal.

--
error compiling committee.c: too many arguments to function