Xen (HVM) and NMI

[Andriy Gapon]

On 07/11/2019 20:08, Andriy Gapon wrote:
> For CPUs that do get interrupted I see stack traces like:
> cpustop_handler+0x28 ipi_nmi_handler+0x44 xen_cpustophard_handler+0x9
> intr_event_handle+0x8b intr_execute_handlers+0x58 xen_intr_handle_upcall+0x15a
> xen_intr_upcall_u+0x96 ...
> So, it looks like the NMI is delivered by the same mechanism as normal
> interrupts.  If a processor has interrupts disabled then the NMI would not get
> delivered?
> 
> Is there anything we could do to improve this?

I found this in Linux code:
    HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu), NULL);
It's in xen_send_IPI_one().
I wonder if that's that or if there is more to this than meets the eye.
Any help and advice is appreciated!

-- 
Andriy Gapon