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

Frederic Weisbecker
2009-10-25T23:31:46Z

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.

Thanks.