Re: KVM PMU virtualization

["Zhang, Yanmin" <yanmin_zhang@linux.intel.com>]

On Wed, 2010-03-03 at 11:15 +0100, Peter Zijlstra wrote:
> On Wed, 2010-03-03 at 17:27 +0800, Zhang, Yanmin wrote:
> > -#ifndef perf_misc_flags
> > -#define perf_misc_flags(regs)  (user_mode(regs) ? PERF_RECORD_MISC_USER : \
> > -                                PERF_RECORD_MISC_KERNEL)
> > -#define perf_instruction_pointer(regs) instruction_pointer(regs)
> > -#endif 
> 
> Ah, that #ifndef is for powerpc, which I think you just broke.
Thanks for the reminder. I deleted powerpc codes when building cscope
lib.

It seems perf_save_virt_ip/perf_reset_virt_ip interfaces are ugly. I plan to
change them to a callback function struct and kvm registers its version to perf.

Such like:
struct perf_guest_info_callbacks {
	int (*is_in_guest)();
	u64 (*get_guest_ip)();
	int (*copy_guest_stack)();
	int (*reset_in_guest)();
	...
};
int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *);
int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *);

It's more scalable and neater.