> Second, I wanted to use NMIs as a way of waking up a vcpu sleeping with 
> interrupts disabled (in the context of Jeremy's paravirt spinlock 
> patches).  Looks like we'll have to use paravirtualization for that.

Just use a mode of perf that doesn't use NMIs.
Interrupt off profiling is rarely needed if at all on modern kernels.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.