On Tue, Nov 1, 2022 at 5:30 AM Andrew Jones <ajones@xxxxxxxxxxxxxxxx> wrote: > > On Mon, Jul 18, 2022 at 10:01:57AM -0700, Atish Patra wrote: > > KVM module needs to know how many hardware counters the platform supports. > > Otherwise, it will not be able to show optimal value of virtual > ^ the > > counters to the guest. > > > > Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> > > --- > > drivers/perf/riscv_pmu_sbi.c | 23 +++++++++++++++++------ > > include/linux/perf/riscv_pmu.h | 4 ++++ > > 2 files changed, 21 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > > index 24124546844c..1723af68ffa1 100644 > > --- a/drivers/perf/riscv_pmu_sbi.c > > +++ b/drivers/perf/riscv_pmu_sbi.c > > @@ -27,6 +27,7 @@ > > */ > > static union sbi_pmu_ctr_info *pmu_ctr_list; > > static unsigned int riscv_pmu_irq; > > +static struct riscv_pmu *rvpmu; > > Do we really need rvpmu? From a quick scan of the series it's only used > for num_hw_counters, which has to be added to struct riscv_pmu, and > num_counters. How about instead creating a static global for num_counters Yes. I added rvpmu just for future usage if any. > and then getting num_hw_counters by iterating pmu_ctr_list. If we want iteration is fine as we are doing that for hpm_width anyways. > riscv_pmu_sbi_get_num_hw_ctrs() to be faster, then we can cache the value > in a static variable in the function. > We have cmask now which can be cached in a static variable. We need to retrieve the counter width and the hardware counters for kvm. I have combined PATCH 1 & PATCH 2 to return both the values in one function. > Thanks, > drew -- Regards, Atish
