Re: [PATCH] x86: make compat_iret() domain crash cases distinguishable

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 02/11/15 10:56, Jan Beulich wrote:
>>>> On 30.10.15 at 20:05, <andrew.cooper3@citrix.com> wrote:
>> On 30/10/15 17:46, Jan Beulich wrote:
>>> Rather than issuing a (mostly) useless separate message, rely on
>>> domain_crash() providing enough data, and leverage the line number
>>> information it prints.
>>>
>>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> The messages are not completely useless, and they do save a round-trip
>> to the debug symbols (which can be a very long RTT when dealing with
>> customers).
>>
>> I agree that moving the domain_crash()'s is a good idea, but can we get
>> away with just demoing the gprintk()s to gdprintk()s ?
> How would that aid with the customer case (who wouldn't normally run
> debug hypervisors)?

I suppose it wouldn't in the general case.

XenServer now ships both regular and debug hypervisors to short circuit
the first RTT when dealing with host crashes.  A side effect is that
guest crashes can be diagnosed more easily by switching to the debug
hypervisor.

~Andrew