Re: [PATCH v1 2/3] KVM: selftests: aarch64: Move the pmu helper function into lib/
From: Raghavendra Rao Ananta
Date: Mon Nov 27 2023 - 16:49:12 EST
Hi Shaoqin,
On Wed, Nov 22, 2023 at 10:39 PM Shaoqin Huang <shahuang@xxxxxxxxxx> wrote:
>
> Move those pmu helper function into lib/, thus it can be used by other
> pmu test.
>
> Signed-off-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
> ---
> .../kvm/aarch64/vpmu_counter_access.c | 118 -----------------
> .../selftests/kvm/include/aarch64/vpmu.h | 119 ++++++++++++++++++
> 2 files changed, 119 insertions(+), 118 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> index 17305408a334..62d6315790ab 100644
> --- a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> +++ b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> @@ -20,12 +20,6 @@
> #include <perf/arm_pmuv3.h>
> #include <linux/bitfield.h>
>
> -/* The max number of the PMU event counters (excluding the cycle counter) */
> -#define ARMV8_PMU_MAX_GENERAL_COUNTERS (ARMV8_PMU_MAX_COUNTERS - 1)
> -
> -/* The cycle counter bit position that's common among the PMU registers */
> -#define ARMV8_PMU_CYCLE_IDX 31
> -
> static struct vpmu_vm *vpmu_vm;
>
> struct pmreg_sets {
> @@ -35,118 +29,6 @@ struct pmreg_sets {
>
> #define PMREG_SET(set, clr) {.set_reg_id = set, .clr_reg_id = clr}
>
> -static uint64_t get_pmcr_n(uint64_t pmcr)
> -{
> - return (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
> -}
> -
> -static void set_pmcr_n(uint64_t *pmcr, uint64_t pmcr_n)
> -{
> - *pmcr = *pmcr & ~(ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT);
> - *pmcr |= (pmcr_n << ARMV8_PMU_PMCR_N_SHIFT);
> -}
> -
> -static uint64_t get_counters_mask(uint64_t n)
> -{
> - uint64_t mask = BIT(ARMV8_PMU_CYCLE_IDX);
> -
> - if (n)
> - mask |= GENMASK(n - 1, 0);
> - return mask;
> -}
> -
> -/* Read PMEVTCNTR<n>_EL0 through PMXEVCNTR_EL0 */
> -static inline unsigned long read_sel_evcntr(int sel)
> -{
> - write_sysreg(sel, pmselr_el0);
> - isb();
> - return read_sysreg(pmxevcntr_el0);
> -}
> -
> -/* Write PMEVTCNTR<n>_EL0 through PMXEVCNTR_EL0 */
> -static inline void write_sel_evcntr(int sel, unsigned long val)
> -{
> - write_sysreg(sel, pmselr_el0);
> - isb();
> - write_sysreg(val, pmxevcntr_el0);
> - isb();
> -}
> -
> -/* Read PMEVTYPER<n>_EL0 through PMXEVTYPER_EL0 */
> -static inline unsigned long read_sel_evtyper(int sel)
> -{
> - write_sysreg(sel, pmselr_el0);
> - isb();
> - return read_sysreg(pmxevtyper_el0);
> -}
> -
> -/* Write PMEVTYPER<n>_EL0 through PMXEVTYPER_EL0 */
> -static inline void write_sel_evtyper(int sel, unsigned long val)
> -{
> - write_sysreg(sel, pmselr_el0);
> - isb();
> - write_sysreg(val, pmxevtyper_el0);
> - isb();
> -}
> -
> -static inline void enable_counter(int idx)
> -{
> - uint64_t v = read_sysreg(pmcntenset_el0);
> -
> - write_sysreg(BIT(idx) | v, pmcntenset_el0);
> - isb();
> -}
> -
> -static inline void disable_counter(int idx)
> -{
> - uint64_t v = read_sysreg(pmcntenset_el0);
> -
> - write_sysreg(BIT(idx) | v, pmcntenclr_el0);
> - isb();
> -}
> -
> -static void pmu_disable_reset(void)
> -{
> - uint64_t pmcr = read_sysreg(pmcr_el0);
> -
> - /* Reset all counters, disabling them */
> - pmcr &= ~ARMV8_PMU_PMCR_E;
> - write_sysreg(pmcr | ARMV8_PMU_PMCR_P, pmcr_el0);
> - isb();
> -}
> -
> -#define RETURN_READ_PMEVCNTRN(n) \
> - return read_sysreg(pmevcntr##n##_el0)
> -static unsigned long read_pmevcntrn(int n)
> -{
> - PMEVN_SWITCH(n, RETURN_READ_PMEVCNTRN);
> - return 0;
> -}
> -
> -#define WRITE_PMEVCNTRN(n) \
> - write_sysreg(val, pmevcntr##n##_el0)
> -static void write_pmevcntrn(int n, unsigned long val)
> -{
> - PMEVN_SWITCH(n, WRITE_PMEVCNTRN);
> - isb();
> -}
> -
> -#define READ_PMEVTYPERN(n) \
> - return read_sysreg(pmevtyper##n##_el0)
> -static unsigned long read_pmevtypern(int n)
> -{
> - PMEVN_SWITCH(n, READ_PMEVTYPERN);
> - return 0;
> -}
> -
> -#define WRITE_PMEVTYPERN(n) \
> - write_sysreg(val, pmevtyper##n##_el0)
> -static void write_pmevtypern(int n, unsigned long val)
> -{
> - PMEVN_SWITCH(n, WRITE_PMEVTYPERN);
> - isb();
> -}
> -
> /*
> * The pmc_accessor structure has pointers to PMEV{CNTR,TYPER}<n>_EL0
> * accessors that test cases will use. Each of the accessors will
> diff --git a/tools/testing/selftests/kvm/include/aarch64/vpmu.h b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
> index 0a56183644ee..e0cc1ca1c4b7 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/vpmu.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
> @@ -1,10 +1,17 @@
> /* SPDX-License-Identifier: GPL-2.0 */
>
> #include <kvm_util.h>
> +#include <perf/arm_pmuv3.h>
>
> #define GICD_BASE_GPA 0x8000000ULL
> #define GICR_BASE_GPA 0x80A0000ULL
>
> +/* The max number of the PMU event counters (excluding the cycle counter) */
> +#define ARMV8_PMU_MAX_GENERAL_COUNTERS (ARMV8_PMU_MAX_COUNTERS - 1)
> +
> +/* The cycle counter bit position that's common among the PMU registers */
> +#define ARMV8_PMU_CYCLE_IDX 31
> +
> struct vpmu_vm {
> struct kvm_vm *vm;
> struct kvm_vcpu *vcpu;
> @@ -14,3 +21,115 @@ struct vpmu_vm {
> struct vpmu_vm *create_vpmu_vm(void *guest_code);
>
> void destroy_vpmu_vm(struct vpmu_vm *vpmu_vm);
> +
> +static inline uint64_t get_pmcr_n(uint64_t pmcr)
> +{
> + return (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
> +}
> +
> +static inline void set_pmcr_n(uint64_t *pmcr, uint64_t pmcr_n)
> +{
> + *pmcr = *pmcr & ~(ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT);
> + *pmcr |= (pmcr_n << ARMV8_PMU_PMCR_N_SHIFT);
> +}
> +
> +static inline uint64_t get_counters_mask(uint64_t n)
> +{
> + uint64_t mask = BIT(ARMV8_PMU_CYCLE_IDX);
> +
> + if (n)
> + mask |= GENMASK(n - 1, 0);
> + return mask;
> +}
> +
> +/* Read PMEVTCNTR<n>_EL0 through PMXEVCNTR_EL0 */
> +static inline unsigned long read_sel_evcntr(int sel)
> +{
> + write_sysreg(sel, pmselr_el0);
> + isb();
> + return read_sysreg(pmxevcntr_el0);
> +}
> +
> +/* Write PMEVTCNTR<n>_EL0 through PMXEVCNTR_EL0 */
> +static inline void write_sel_evcntr(int sel, unsigned long val)
> +{
> + write_sysreg(sel, pmselr_el0);
> + isb();
> + write_sysreg(val, pmxevcntr_el0);
> + isb();
> +}
> +
> +/* Read PMEVTYPER<n>_EL0 through PMXEVTYPER_EL0 */
> +static inline unsigned long read_sel_evtyper(int sel)
> +{
> + write_sysreg(sel, pmselr_el0);
> + isb();
> + return read_sysreg(pmxevtyper_el0);
> +}
> +
> +/* Write PMEVTYPER<n>_EL0 through PMXEVTYPER_EL0 */
> +static inline void write_sel_evtyper(int sel, unsigned long val)
> +{
> + write_sysreg(sel, pmselr_el0);
> + isb();
> + write_sysreg(val, pmxevtyper_el0);
> + isb();
> +}
> +
> +static inline void enable_counter(int idx)
> +{
> + uint64_t v = read_sysreg(pmcntenset_el0);
> +
> + write_sysreg(BIT(idx) | v, pmcntenset_el0);
> + isb();
> +}
> +
> +static inline void disable_counter(int idx)
> +{
> + uint64_t v = read_sysreg(pmcntenset_el0);
> +
> + write_sysreg(BIT(idx) | v, pmcntenclr_el0);
> + isb();
> +}
> +
As mentioned in [1], the current implementation of disable_counter()
is buggy and would end up disabling all the counters.
However if you intend to keep it (even though it would remain unused),
may be change the definition something to:
static inline void disable_counter(int idx)
{
write_sysreg(BIT(idx), pmcntenclr_el0);
isb();
}
Thank you.
Raghavendra
[1]: https://lore.kernel.org/all/20231122221526.2750966-1-rananta@xxxxxxxxxx/
> +static inline void pmu_disable_reset(void)
> +{
> + uint64_t pmcr = read_sysreg(pmcr_el0);
> +
> + /* Reset all counters, disabling them */
> + pmcr &= ~ARMV8_PMU_PMCR_E;
> + write_sysreg(pmcr | ARMV8_PMU_PMCR_P, pmcr_el0);
> + isb();
> +}
> +
> +#define RETURN_READ_PMEVCNTRN(n) \
> + return read_sysreg(pmevcntr##n##_el0)
> +static inline unsigned long read_pmevcntrn(int n)
> +{
> + PMEVN_SWITCH(n, RETURN_READ_PMEVCNTRN);
> + return 0;
> +}
> +
> +#define WRITE_PMEVCNTRN(n) \
> + write_sysreg(val, pmevcntr##n##_el0)
> +static inline void write_pmevcntrn(int n, unsigned long val)
> +{
> + PMEVN_SWITCH(n, WRITE_PMEVCNTRN);
> + isb();
> +}
> +
> +#define READ_PMEVTYPERN(n) \
> + return read_sysreg(pmevtyper##n##_el0)
> +static inline unsigned long read_pmevtypern(int n)
> +{
> + PMEVN_SWITCH(n, READ_PMEVTYPERN);
> + return 0;
> +}
> +
> +#define WRITE_PMEVTYPERN(n) \
> + write_sysreg(val, pmevtyper##n##_el0)
> +static inline void write_pmevtypern(int n, unsigned long val)
> +{
> + PMEVN_SWITCH(n, WRITE_PMEVTYPERN);
> + isb();
> +}
> --
> 2.40.1
>
>