| Message ID | 20220718170205.2972215-5-atishp@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM perf support | expand |
On Mon, Jul 18, 2022 at 10:02:00AM -0700, Atish Patra wrote: > Currently, the host driver doesn't have any method to identify if the > requested perf event is from kvm or bare metal. As KVM runs in HS > mode, there are no separate hypervisor privilege mode to distinguish > between the attributes for guest/host. > > Improve the privilege mode filtering by using the event specific > config1 field. > > Signed-off-by: Atish Patra <atishp@rivosinc.com> > --- > drivers/perf/riscv_pmu_sbi.c | 27 ++++++++++++++++++++++----- > include/linux/perf/riscv_pmu.h | 2 ++ > 2 files changed, 24 insertions(+), 5 deletions(-) > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > index 5d0eef3ef136..34f9fcc221a8 100644 > --- a/drivers/perf/riscv_pmu_sbi.c > +++ b/drivers/perf/riscv_pmu_sbi.c > @@ -275,6 +275,27 @@ int riscv_pmu_sbi_hpmc_width(void) > } > EXPORT_SYMBOL(riscv_pmu_sbi_hpmc_width); > > +static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event) > +{ > + unsigned long cflags = 0; > + bool guest_events = false; > + > + if (event->attr.config1 & RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS) > + guest_events = true; > + if (event->attr.exclude_kernel) > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH; > + if (event->attr.exclude_user) > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH; > + if (guest_events && event->attr.exclude_hv) > + cflags |= SBI_PMU_CFG_FLAG_SET_SINH; > + if (event->attr.exclude_host) > + cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH; > + if (event->attr.exclude_guest) > + cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH; > + > + return cflags; > +} > + > static int pmu_sbi_ctr_get_idx(struct perf_event *event) > { > struct hw_perf_event *hwc = &event->hw; > @@ -286,11 +307,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) > uint64_t cmask = GENMASK_ULL(rvpmu->num_counters - 1, 0); > unsigned long cflags = 0; > > - if (event->attr.exclude_kernel) > - cflags |= SBI_PMU_CFG_FLAG_SET_SINH; > - if (event->attr.exclude_user) > - cflags |= SBI_PMU_CFG_FLAG_SET_UINH; > - > + cflags = pmu_sbi_get_filter_flags(event); > /* retrieve the available counter index */ > #if defined(CONFIG_32BIT) > ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask, > diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h > index 6fee211c27b5..825b95253bc5 100644 > --- a/include/linux/perf/riscv_pmu.h > +++ b/include/linux/perf/riscv_pmu.h > @@ -26,6 +26,8 @@ > > #define RISCV_PMU_STOP_FLAG_RESET 1 > > +#define RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS 0x1 > + > struct cpu_hw_events { > /* currently enabled events */ > int n_events; > -- > 2.25.1 > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Hi Atish, > Currently, the host driver doesn't have any method to identify if the > requested perf event is from kvm or bare metal. As KVM runs in HS > mode, there are no separate hypervisor privilege mode to distinguish > between the attributes for guest/host. > > Improve the privilege mode filtering by using the event specific > config1 field. ... [snip] > +static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event) > +{ > + unsigned long cflags = 0; > + bool guest_events = false; > + > + if (event->attr.config1 & RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS) > + guest_events = true; > + if (event->attr.exclude_kernel) > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH; IIUC we should inhibit host counting if we want guest events: cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_SINH : SBI_PMU_CFG_FLAG_SET_VSINH; > + if (event->attr.exclude_user) > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH; Same here. > + if (guest_events && event->attr.exclude_hv) > + cflags |= SBI_PMU_CFG_FLAG_SET_SINH; > + if (event->attr.exclude_host) > + cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH; > + if (event->attr.exclude_guest) > + cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH; > + > + return cflags; > +} Regards, Sergey
On Wed, Nov 9, 2022 at 5:42 AM Sergey Matyukevich <geomatsi@gmail.com> wrote: > > Hi Atish, > > > Currently, the host driver doesn't have any method to identify if the > > requested perf event is from kvm or bare metal. As KVM runs in HS > > mode, there are no separate hypervisor privilege mode to distinguish > > between the attributes for guest/host. > > > > Improve the privilege mode filtering by using the event specific > > config1 field. > > ... [snip] > > > +static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event) > > +{ > > + unsigned long cflags = 0; > > + bool guest_events = false; > > + > > + if (event->attr.config1 & RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS) > > + guest_events = true; > > + if (event->attr.exclude_kernel) > > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH; > > IIUC we should inhibit host counting if we want guest events: > cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_SINH : SBI_PMU_CFG_FLAG_SET_VSINH; > guest_events indicate that the user in the guest VM is configured to exclude the kernel i.e. the guest kernel which is running in VS mode. That's why, we have to set SBI_PMU_CFG_FLAG_SET_VSINH To inhibit host counting, the user needs to specify exclude_host and/or exclude_hv which happens below as well. > > + if (event->attr.exclude_user) > > + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH; > > Same here. > Same explanation as above. > > + if (guest_events && event->attr.exclude_hv) > > + cflags |= SBI_PMU_CFG_FLAG_SET_SINH; > > + if (event->attr.exclude_host) > > + cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH; > > + if (event->attr.exclude_guest) > > + cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH; > > + > > + return cflags; > > +} > > Regards, > Sergey
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 5d0eef3ef136..34f9fcc221a8 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -275,6 +275,27 @@ int riscv_pmu_sbi_hpmc_width(void) } EXPORT_SYMBOL(riscv_pmu_sbi_hpmc_width); +static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event) +{ + unsigned long cflags = 0; + bool guest_events = false; + + if (event->attr.config1 & RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS) + guest_events = true; + if (event->attr.exclude_kernel) + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH; + if (event->attr.exclude_user) + cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH; + if (guest_events && event->attr.exclude_hv) + cflags |= SBI_PMU_CFG_FLAG_SET_SINH; + if (event->attr.exclude_host) + cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH; + if (event->attr.exclude_guest) + cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH; + + return cflags; +} + static int pmu_sbi_ctr_get_idx(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; @@ -286,11 +307,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) uint64_t cmask = GENMASK_ULL(rvpmu->num_counters - 1, 0); unsigned long cflags = 0; - if (event->attr.exclude_kernel) - cflags |= SBI_PMU_CFG_FLAG_SET_SINH; - if (event->attr.exclude_user) - cflags |= SBI_PMU_CFG_FLAG_SET_UINH; - + cflags = pmu_sbi_get_filter_flags(event); /* retrieve the available counter index */ #if defined(CONFIG_32BIT) ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask, diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h index 6fee211c27b5..825b95253bc5 100644 --- a/include/linux/perf/riscv_pmu.h +++ b/include/linux/perf/riscv_pmu.h @@ -26,6 +26,8 @@ #define RISCV_PMU_STOP_FLAG_RESET 1 +#define RISCV_KVM_PMU_CONFIG1_GUEST_EVENTS 0x1 + struct cpu_hw_events { /* currently enabled events */ int n_events;
Currently, the host driver doesn't have any method to identify if the requested perf event is from kvm or bare metal. As KVM runs in HS mode, there are no separate hypervisor privilege mode to distinguish between the attributes for guest/host. Improve the privilege mode filtering by using the event specific config1 field. Signed-off-by: Atish Patra <atishp@rivosinc.com> --- drivers/perf/riscv_pmu_sbi.c | 27 ++++++++++++++++++++++----- include/linux/perf/riscv_pmu.h | 2 ++ 2 files changed, 24 insertions(+), 5 deletions(-)