On Thu, Aug 01, 2024 at 04:58:23AM +0000, Mingwei Zhang wrote:
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> There will be a dedicated interrupt vector for guests on some platforms,
> e.g., Intel. Add an interface to switch the interrupt vector while
> entering/exiting a guest.
>
> When PMI switch into a new guest vector, guest_lvtpc value need to be
> reflected onto HW, e,g., guest clear PMI mask bit, the HW PMI mask
> bit should be cleared also, then PMI can be generated continuously
> for guest. So guest_lvtpc parameter is added into perf_guest_enter()
> and switch_interrupt().
>
> At switch_interrupt(), the target pmu with PASSTHROUGH cap should
> be found. Since only one passthrough pmu is supported, we keep the
> implementation simply by tracking the pmu as a global variable.
>
> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> [Simplify the commit with removal of srcu lock/unlock since only one pmu is
> supported.]
>
> Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
> ---
> include/linux/perf_event.h | 9 +++++++--
> kernel/events/core.c | 36 ++++++++++++++++++++++++++++++++++--
> 2 files changed, 41 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 75773f9890cc..aeb08f78f539 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -541,6 +541,11 @@ struct pmu {
> * Check period value for PERF_EVENT_IOC_PERIOD ioctl.
> */
> int (*check_period) (struct perf_event *event, u64 value); /* optional */
> +
> + /*
> + * Switch the interrupt vectors, e.g., guest enter/exit.
> + */
> + void (*switch_interrupt) (bool enter, u32 guest_lvtpc); /* optional */
> };
I'm thinking the guets_lvtpc argument shouldn't be part of the
interface. That should be PMU implementation data and accessed by the
method implementation.
