On 01/18/2010 10:55 PM, Gleb Natapov wrote: >> >> What I mean is that vector 14 is page faults -- that's what it is all >> about. Why on Earth do you need another vector? >> > Because this is not usual pagefault that tell the OS that page is not > mapped. This is a notification to a guest OS that the page it is trying > to access is swapped out by the host OS. There is nothing guest can do > about it except schedule another task. So the guest should handle both > type of exceptions: usual #PF when page is not mapped by the guest and > new type of notifications. Ideally we would use one of unused exception > vectors for new type of notifications. > Ah, this kind of stuff. We have talked about this in the past, and the right way to do that is to have the guest OS pick a vector our of the standard 0x20-0xff range, and then notify the hypervisor via a hypercall which vector to use. In Linux this means marking it as a system vector. Note that there are real hardware system vectors which will be mutually exclusive with this, e.g. the UV one. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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
