Re: Hypervisor to dom0 communication

[Razvan Cojocaru <rzvncj@gmail.com>]

>> OK, my immediate end-goal is real-time logging of hypervisor events via
>> a dom0 userspace application. These events are always about a currently
>> running virtual machine, and said virtual machine is paused at the time.
>> The userspace tool should be immediately notified, so no polling.
>
> This is very like the ioreq model, where the domain (or maybe just the
> vcpu, I'm not sure) is paused while qemu does its thing.
>
> What sort of events are we talking about here?

A list of interesting registers that changed, that a page fault occured, 
things like that, occasionally containing some small string messages 
with extra information. Should be around 64 bytes or so.

> The right thing to do here is for the userspace tool to communicate with
> the toolstack (by whatever means) rather the hypervisor in order to
> control the domains.

That's what I was thinking too.

> You might also find some inspiration for this sort of model in the
> xenpaging and memshare code.

Will look those things up, I appreciate the replies.

Thanks,
Razvan