Gleb Natapov wrote:
On Sun, Apr 19, 2009 at 05:20:37PM +0300, Avi Kivity wrote:
Gleb Natapov wrote:
Could you elaborate on that? How/why does it use NMIs for task
switching?
During WHQL testing (or if you just enable verifier on windows 2003)
windows changes hibernate to not power down a PC, but resume
immediately. During this immediate resume it sends NMI to non-boot CPUs
while IDT for nmi is configured as a task gate. I am not sure it
actually calls IRET after that.
If it doesn't call IRET, it will never see another NMI.
But of course it will execute IRET, as part of normal execution. You
can't do anything without it.
Boot CPU can send INIT after task switch (and I think this is what
happens).
But eventually it will execute IRET.
(We need to fix INIT to clear the NMI blocking flag, not that it matters
so much)
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
--
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
