Re: [PATCH 4/6] hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events

Jan Kiszka
2009-10-26T08:17:30Z

[-- Attachment #1: Type: text/plain, Size: 748 bytes --]

Frederic Weisbecker wrote:
> 2009/10/24 Jan Kiszka <jan.kiszka@web.de>:
>> Since commit 3d53c27d05, KVM uses current->thread.debugregs for
>> restoring the host state in case the guest played with breakpoints. We
>> need an equivalent interface to restore ptrace breakpoints and all
>> others currently in use.
>>
>> Jan
>
>
> Well, dr6 is still stored in the current thread.
> dr7 has a per cpu variable containing its value.
>
> So what remains is to have a per cpu variable for dr0-3
> which is updated when perf schedules in/out a profiled context.
> I can do that in a v3.

Sounds great. Maybe you can stuff all this into some function kvm can
call to avoid that it has to peek into various internal structures.

Jan

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 257 bytes --]