Re: [Xen-devel] [PATCH V3] vmx/nmi: Do not use self_nmi() in VMEXIT handler

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 22.11.12 at 17:05, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
> On 22/11/12 15:55, Jan Beulich wrote:
>>>>> On 22.11.12 at 16:37, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
>>> A quick solution would be to execute a noop function with
>>> run_in_exception_handler().  Alternatively, I can code enable_nmi() or
>>> so which does an inline iret to itself.  Which of these would you prefer?
>> I would actually consider avoiding to run softirqs altogether in that
>> case, just like native Linux doesn't do any event or scheduler
>> processing in that case.
> 
> That would probably be the easiest solution.
> 
> I was already going to do the same for the rentrant NMI and MCE handling
> case (and also the process pending upcalls checking), due to the
> complexities of fixing the race condition at the end of the handler.
> 
> Unfortunately, I don't think I have time to look at this issue
> immediately, but if it is ok to wait till the beginning of next week, I

That's fine of course.

> can roll it into the main dev work for the other NMI/MCE work.

Hmm, that would mean it's going to be more difficult to backport.
I'd prefer having this in as simple a fashion as possible in the
patch here, and then have your other patch(es) build on top of
that.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel