[tip:x86/debug] x86/kdump: No need to disable ioapic/ lapic in crash path

[Vivek Goyal]

On Wed, Mar 07, 2012 at 07:53:16PM +0900, Fernando Luis Vázquez Cao wrote:
> On 03/01/2012 08:19 AM, Eric W. Biederman wrote:
> 
> >Don Zickus<dzickus at redhat.com>  writes:
> >>It probably is, except I never hacked on idt code before and my assembly
> >>isn't that good.  I have been trying to find examples to copy from to give
> >>it a try.  So far I was using early_idt_handlers with early_printk to see
> >>if I could capture some printk messages while jumping from the first
> >>kernel to the second kernel (when the other early_idt_handlers would kick
> >>in for the second kernel).
> >>
> >>Tips?  Better examples?
> >That is a particularly good example.  When I took a quick look earlier
> >that is the first place we reload the idt in the kernel boot so that is
> >one of two places that needs to be modified.
> 
> Hi Eric, Don
> 
> Sorry for chiming in so late.
> 
> We run into the same NMI problems and wrote some patches that tackle
> the kernel boot side of things. They have been extensively tested using
> qemu-kvm and things seem to be working as expected (after receiving an
> early NMI the kernel continues without problem; after the iret there is no
> stack corruption or register corruption).

What happens if NMI happens while we are still in purgatory code?

Thanks
Vivek