Re: To use xcs or not?

[Anthony Liguori <anthony@codemonkey.ws>]

Jacob Gorm Hansen wrote:

> I am creating a graphics system where each VM draws into an OpenGL 
> surface of a process running in dom0. I need to syncronize updates, 
> ideally with the vertical blanking of the screen, but in the world of 
> stupid PC hardware probably just with some refresh timer that my 
> OpenGL process is tied to.

Neat, is this some sort of specialized application or are you 
implementing a virtual frame buffer?

> So when the screen has been redrawn, I need to wake up my domUs, and 
> for this I wanted to use the ctrl_if mechanism. I borrowed some code 
> from vm-shutdown in the (very nice) vm-tools package, setup a 
> semaphore in the guest kernel, and for every screen update I send an 
> XCS_REQUEST (only type that seems to do anything) up to the domU.

This is probably a little overkill.  If all you need is notification, 
you probably just want to setup your own evtchn. 

> This works fine for a little while (1000 updates or so), whereafter 
> xcs seems to go into an infinite loop. I am going

xcs has some problems.  It needs some work.

Regards,

-- 
Anthony Liguori
anthony@codemonkey.ws



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