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    Subject[PATCH v3 02/14] perf: RISC-V: Improve privilege mode filtering for perf
    Date
    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.

    Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
    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 6b53adc..e862b13 100644
    --- a/drivers/perf/riscv_pmu_sbi.c
    +++ b/drivers/perf/riscv_pmu_sbi.c
    @@ -301,6 +301,27 @@ int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr)
    }
    EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info);

    +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;
    @@ -311,11 +332,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event)
    uint64_t cbase = 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,
    diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h
    index a1c3f77..1c42146 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
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