On 2024-11-06 2:53 p.m., Oliver Upton wrote:
> On Wed, Nov 06, 2024 at 11:07:53AM -0500, Liang, Kan wrote:
>>> +#ifndef perf_arch_guest_misc_flags
>>> +static inline unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
>>> +{
>>> + unsigned long guest_state = perf_guest_state();
>>> +
>>> + if (guest_state & PERF_GUEST_USER)
>>> + return PERF_RECORD_MISC_GUEST_USER;
>>> +
>>> + if (guest_state & PERF_GUEST_ACTIVE)
>>> + return PERF_RECORD_MISC_GUEST_KERNEL;
>>
>> Is there by any chance to add a PERF_GUEST_KERNEL flag in KVM?
>
> Why do we need another flag? As it stands today, the vCPU is either in
> user mode or kernel mode.
>
>> The PERF_GUEST_ACTIVE flag check looks really confusing.
>
> Perhaps instead:
>
> static inline unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
> {
> unsigned long guest_state = perf_guest_state();
>
> if (!(guest_state & PERF_GUEST_ACTIVE))
> return 0;
>
> return (guest_state & PERF_GUEST_USER) ? PERF_RECORD_MISC_GUEST_USER :
> PERF_RECORD_MISC_GUEST_KERNEL;
> }
Yes, this one is much clear.
Can a similar change be done for the x86 perf_arch_guest_misc_flags() in
the previous patch?
Thanks,
Kan
