Re: [PATCH RFC 0/9] Basic guest memory introspection support

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

On 07/02/2014 05:30 PM, Jan Beulich wrote:
>>>> On 02.07.14 at 15:34, <rcojocaru@bitdefender.com> wrote:
>> 4. Add an additional mem_event type, namely a VMCALL event - in order to
>> do its work, our application occasionally triggers VMCALLs in the guest.
> 
> That seems like bending the mem_event interface quite a bit - VMCALL
> isn't really memory (or event) specific.

First, thank you for the reply.

I don't disagree that it's somewhat bending mem_event, however in the
context of our application it became necessary to know exactly when a
triggered VMCALL occured, so conceptually this was a noteworthy event
for us.

As for using mem_event for it, we chose it because it seems to be the
closest thing to a standard Xen way of handling events, it is quite
stable, and we thought it might not be such a stretch since there's also
MEM_EVENT_REASON_SINGLESTEP.

We thought that adding an extra mem_event type would solve the problem
while adding as little unnecessary complications to the existing code,
and making it as trouble-free as possible for Xen maintainers / testers.


Thanks again,
Razvan Cojocaru