Re: [PATCH] xen: Disable REP MOVSD optimization if introspection is active

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

On 10/27/2014 03:01 PM, Jan Beulich wrote:
>>>> On 27.10.14 at 12:09, <rcojocaru@bitdefender.com> wrote:
>> If you feel that the patch is acceptable, I'll correct the description
>> when submitting V2.
> 
> I think it's not unreasonable conceptually, but I somewhat doubt the
> place you put the change is the right one. For one it only covers
> "rep movs", but not "rep ins" or "rep outs", and then even non-rep
> memory access may be broken up (due to the 8 byte limit of the
> channel to qemu). For me (lacking sufficient mem-event knowledge)
> it is quite hard to tell whether your change perhaps should be near
> the actual generation of the mem-event (simply because I can't -
> without spending more time than I have for this - right now see
> where exactly that event gets generated). Perhaps
> hvmemul_virtual_to_linear() should be made force *reps to 1 in
> that case instead of making various functions return failure?

Thank you, that's certainly a more elegant way to handle it than my
hack. I'll test it with reps set to 1 in hvmemul_virtual_to_linear(),
and if all goes well and there are no objections to this way of handling
it, will submit a new patch.


Thanks,
Razvan