Commit 8929283a authored by Atish Patra's avatar Atish Patra Committed by Anup Patel
Browse files

perf: RISC-V: Improve privilege mode filtering for perf 



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: default avatarAndrew Jones <ajones@ventanamicro.com>
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Signed-off-by: default avatarAtish Patra <atishp@rivosinc.com>
Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 585e351f

drivers/perf/riscv_pmu_sbi.c

+22 −5
Original line number Diff line number Diff line
@@ -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_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,

include/linux/perf/riscv_pmu.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 


#define RISCV_PMU_STOP_FLAG_RESET 1



#define RISCV_PMU_CONFIG1_GUEST_EVENTS 0x1



struct cpu_hw_events {

	/* currently enabled events */

	int			n_events;