Add a new test case to the vpmu_counter_access test to check if PMU registers or their bits for implemented counters on the vCPU are readable/writable as expected, and can be programmed to count events.
Signed-off-by: Reiji Watanabe <[email protected]> --- .../kvm/aarch64/vpmu_counter_access.c | 347 +++++++++++++++++- 1 file changed, 344 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c index 4760030eee28..5b9d837f903a 100644 --- a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c +++ b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c @@ -5,7 +5,8 @@ * Copyright (c) 2022 Google LLC. * * This test checks if the guest can see the same number of the PMU event - * counters (PMCR_EL1.N) that userspace sets. + * counters (PMCR_EL1.N) that userspace sets, and if the guest can access + * those counters. * This test runs only when KVM_CAP_ARM_PMU_V3 is supported on the host. */ #include <kvm_util.h> @@ -18,19 +19,350 @@ /* The max number of the PMU event counters (excluding the cycle counter) */ #define ARMV8_PMU_MAX_GENERAL_COUNTERS (ARMV8_PMU_MAX_COUNTERS - 1) +/* + * The macros and functions below for reading/writing PMEVT{CNTR,TYPER}<n>_EL0 + * were basically copied from arch/arm64/kernel/perf_event.c. + */ +#define PMEVN_CASE(n, case_macro) \ + case n: case_macro(n); break + +#define PMEVN_SWITCH(x, case_macro) \ + do { \ + switch (x) { \ + PMEVN_CASE(0, case_macro); \ + PMEVN_CASE(1, case_macro); \ + PMEVN_CASE(2, case_macro); \ + PMEVN_CASE(3, case_macro); \ + PMEVN_CASE(4, case_macro); \ + PMEVN_CASE(5, case_macro); \ + PMEVN_CASE(6, case_macro); \ + PMEVN_CASE(7, case_macro); \ + PMEVN_CASE(8, case_macro); \ + PMEVN_CASE(9, case_macro); \ + PMEVN_CASE(10, case_macro); \ + PMEVN_CASE(11, case_macro); \ + PMEVN_CASE(12, case_macro); \ + PMEVN_CASE(13, case_macro); \ + PMEVN_CASE(14, case_macro); \ + PMEVN_CASE(15, case_macro); \ + PMEVN_CASE(16, case_macro); \ + PMEVN_CASE(17, case_macro); \ + PMEVN_CASE(18, case_macro); \ + PMEVN_CASE(19, case_macro); \ + PMEVN_CASE(20, case_macro); \ + PMEVN_CASE(21, case_macro); \ + PMEVN_CASE(22, case_macro); \ + PMEVN_CASE(23, case_macro); \ + PMEVN_CASE(24, case_macro); \ + PMEVN_CASE(25, case_macro); \ + PMEVN_CASE(26, case_macro); \ + PMEVN_CASE(27, case_macro); \ + PMEVN_CASE(28, case_macro); \ + PMEVN_CASE(29, case_macro); \ + PMEVN_CASE(30, case_macro); \ + default: \ + GUEST_ASSERT_1(0, x); \ + } \ + } while (0) + +#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(); +} + +/* 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 PMEVTTYPER<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 PMEVTTYPER<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(); +} + +/* + * The pmc_accessor structure has pointers to PMEVT{CNTR,TYPER}<n>_EL0 + * accessors that test cases will use. Each of the accessors will + * either directly reads/writes PMEVT{CNTR,TYPER}<n>_EL0 + * (i.e. {read,write}_pmev{cnt,type}rn()), or reads/writes them through + * PMXEV{CNTR,TYPER}_EL0 (i.e. {read,write}_sel_ev{cnt,type}r()). + * + * This is used to test that combinations of those accessors provide + * the consistent behavior. + */ +struct pmc_accessor { + /* A function to be used to read PMEVTCNTR<n>_EL0 */ + unsigned long (*read_cntr)(int idx); + /* A function to be used to write PMEVTCNTR<n>_EL0 */ + void (*write_cntr)(int idx, unsigned long val); + /* A function to be used to read PMEVTTYPER<n>_EL0 */ + unsigned long (*read_typer)(int idx); + /* A function to be used write PMEVTTYPER<n>_EL0 */ + void (*write_typer)(int idx, unsigned long val); +}; + +struct pmc_accessor pmc_accessors[] = { + /* test with all direct accesses */ + { read_pmevcntrn, write_pmevcntrn, read_pmevtypern, write_pmevtypern }, + /* test with all indirect accesses */ + { read_sel_evcntr, write_sel_evcntr, read_sel_evtyper, write_sel_evtyper }, + /* read with direct accesses, and write with indirect accesses */ + { read_pmevcntrn, write_sel_evcntr, read_pmevtypern, write_sel_evtyper }, + /* read with indirect accesses, and write with direct accesses */ + { read_sel_evcntr, write_pmevcntrn, read_sel_evtyper, write_pmevtypern }, +}; + +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(); +} + +static void pmu_enable(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(); +} + +static bool pmu_event_is_supported(uint64_t event) +{ + GUEST_ASSERT_1(event < 64, event); + return (read_sysreg(pmceid0_el0) & BIT(event)); +} + static uint64_t pmcr_extract_n(uint64_t pmcr_val) { return (pmcr_val >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK; } +#define GUEST_ASSERT_BITMAP_REG(regname, mask, set_expected) \ +{ \ + uint64_t _tval = read_sysreg(regname); \ + \ + if (set_expected) \ + GUEST_ASSERT_3((_tval & mask), _tval, mask, set_expected); \ + else \ + GUEST_ASSERT_3(!(_tval & mask), _tval, mask, set_expected);\ +} + +/* + * Check if @mask bits in {PMCNTEN,PMOVS}{SET,CLR} registers + * are set or cleared as specified in @set_expected. + */ +static void check_bitmap_pmu_regs(uint64_t mask, bool set_expected) +{ + GUEST_ASSERT_BITMAP_REG(pmcntenset_el0, mask, set_expected); + GUEST_ASSERT_BITMAP_REG(pmcntenclr_el0, mask, set_expected); + GUEST_ASSERT_BITMAP_REG(pmovsset_el0, mask, set_expected); + GUEST_ASSERT_BITMAP_REG(pmovsclr_el0, mask, set_expected); +} + +/* + * Check if the bit in {PMCNTEN,PMOVS}{SET,CLR} registers corresponding + * to the specified counter (@pmc_idx) can be read/written as expected. + * When @set_op is true, it tries to set the bit for the counter in + * those registers by writing the SET registers (the bit won't be set + * if the counter is not implemented though). + * Otherwise, it tries to clear the bits in the registers by writing + * the CLR registers. + * Then, it checks if the values indicated in the registers are as expected. + */ +static void test_bitmap_pmu_regs(int pmc_idx, bool set_op) +{ + uint64_t pmcr_n, test_bit = BIT(pmc_idx); + bool set_expected = false; + + if (set_op) { + write_sysreg(test_bit, pmcntenset_el0); + write_sysreg(test_bit, pmovsset_el0); + + /* The bit will be set only if the counter is implemented */ + pmcr_n = pmcr_extract_n(read_sysreg(pmcr_el0)); + set_expected = (pmc_idx < pmcr_n) ? true : false; + } else { + write_sysreg(test_bit, pmcntenclr_el0); + write_sysreg(test_bit, pmovsclr_el0); + } + check_bitmap_pmu_regs(test_bit, set_expected); +} + +/* + * Tests for reading/writing registers for the (implemented) event counter + * specified by @pmc_idx. + */ +static void test_access_pmc_regs(struct pmc_accessor *acc, int pmc_idx) +{ + uint64_t write_data, read_data, read_data_prev, test_bit; + + /* Disable all PMCs and reset all PMCs to zero. */ + pmu_disable_reset(); + + + /* + * Tests for reading/writing {PMCNTEN,PMOVS}{SET,CLR}_EL1. + */ + + test_bit = 1ul << pmc_idx; + /* Make sure that the bit in those registers are set to 0 */ + test_bitmap_pmu_regs(test_bit, false); + /* Test if setting the bit in those registers works */ + test_bitmap_pmu_regs(test_bit, true); + /* Test if clearing the bit in those registers works */ + test_bitmap_pmu_regs(test_bit, false); + + + /* + * Tests for reading/writing the event type register. + */ + + read_data = acc->read_typer(pmc_idx); + /* + * Set the event type register to an arbitrary value just for testing + * of reading/writing the register. + * ArmARM says that for the event from 0x0000 to 0x003F, + * the value indicated in the PMEVTYPER<n>_EL0.evtCount field is + * the value written to the field even when the specified event + * is not supported. + */ + write_data = (ARMV8_PMU_EXCLUDE_EL1 | ARMV8_PMUV3_PERFCTR_INST_RETIRED); + acc->write_typer(pmc_idx, write_data); + read_data = acc->read_typer(pmc_idx); + GUEST_ASSERT_4(read_data == write_data, + pmc_idx, acc, read_data, write_data); + + + /* + * Tests for reading/writing the event count register. + */ + + read_data = acc->read_cntr(pmc_idx); + + /* The count value must be 0, as it is not used after the reset */ + GUEST_ASSERT_3(read_data == 0, pmc_idx, acc, read_data); + + write_data = read_data + pmc_idx + 0x12345; + acc->write_cntr(pmc_idx, write_data); + read_data = acc->read_cntr(pmc_idx); + GUEST_ASSERT_4(read_data == write_data, + pmc_idx, acc, read_data, write_data); + + + /* The following test requires the INST_RETIRED event support. */ + if (!pmu_event_is_supported(ARMV8_PMUV3_PERFCTR_INST_RETIRED)) + return; + + pmu_enable(); + acc->write_typer(pmc_idx, ARMV8_PMUV3_PERFCTR_INST_RETIRED); + + /* + * Make sure that the counter doesn't count the INST_RETIRED + * event when disabled, and the counter counts the event when enabled. + */ + disable_counter(pmc_idx); + read_data_prev = acc->read_cntr(pmc_idx); + read_data = acc->read_cntr(pmc_idx); + GUEST_ASSERT_4(read_data == read_data_prev, + pmc_idx, acc, read_data, read_data_prev); + + enable_counter(pmc_idx); + read_data = acc->read_cntr(pmc_idx); + + /* + * The counter should be increased by at least 1, as there is at + * least one instruction between enabling the counter and reading + * the counter (the test assumes that all event counters are not + * being used by the host's higher priority events). + */ + GUEST_ASSERT_4(read_data > read_data_prev, + pmc_idx, acc, read_data, read_data_prev); +} + /* * The guest is configured with PMUv3 with @expected_pmcr_n number of * event counters. - * Check if @expected_pmcr_n is consistent with PMCR_EL0.N. + * Check if @expected_pmcr_n is consistent with PMCR_EL0.N, and + * if reading/writing PMU registers for implemented counters can work + * as expected. */ static void guest_code(uint64_t expected_pmcr_n) { uint64_t pmcr, pmcr_n; + int i, pmc; GUEST_ASSERT(expected_pmcr_n <= ARMV8_PMU_MAX_GENERAL_COUNTERS); @@ -40,6 +372,15 @@ static void guest_code(uint64_t expected_pmcr_n) /* Make sure that PMCR_EL0.N indicates the value userspace set */ GUEST_ASSERT_2(pmcr_n == expected_pmcr_n, pmcr_n, expected_pmcr_n); + /* + * Tests for reading/writing PMU registers for implemented counters. + * Use each combination of PMEVT{CNTR,TYPER}<n>_EL0 accessor functions. + */ + for (i = 0; i < ARRAY_SIZE(pmc_accessors); i++) { + for (pmc = 0; pmc < pmcr_n; pmc++) + test_access_pmc_regs(&pmc_accessors[i], pmc); + } + GUEST_DONE(); } @@ -97,7 +438,7 @@ static void run_vcpu(struct kvm_vcpu *vcpu, uint64_t pmcr_n) vcpu_run(vcpu); switch (get_ucall(vcpu, &uc)) { case UCALL_ABORT: - REPORT_GUEST_ASSERT_2(uc, "values:%#lx %#lx"); + REPORT_GUEST_ASSERT_4(uc, "values:%#lx %#lx %#lx %#lx"); break; case UCALL_DONE: break; -- 2.39.0.314.g84b9a713c41-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
