On Wed, Mar 21, 2012 at 11:18:16AM -0500, Corey Minyard wrote: > > >Look at drivers/char/ipmi/ipmi_msghandler.c. It has code to send panic > >event over IMPI. The code is pretty complex. Of course if we a going to > >implement something more complex than simple hypercall for panic > >notification we better do something more interesting with it than just > >saying "panic happened", like sending stack traces on all cpus for > >instance. > > I doubt that's the best example, unfortunately. The IPMI event log > has limited space and it has to be send a little piece at a time > since each log entry is 14 bytes. It just prints the panic string, > nothing else. Not that it isn't useful, it has saved my butt > before. > I gave ipmi example just to show that others do complex things on panic, not as an example of what we should do on a guest panic. > You have lots of interesting options with paravirtualization. You > could, for instance, create a console driver that delivered all > console output efficiently through a hypercall. That would be > really easy. Or, as you mention, a custom way to deliver panic > information. Collecting information like stack traces would be > harder to accomplish, as I don't think there is currently a way to > get it except by sending it to printk. > Why using hypercall for that though? You can do that with virtio-console. Make it zero config: virtio-console detected -> send console output there. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
