diff options
Diffstat (limited to 'tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c')
-rw-r--r-- | tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c | 670 |
1 files changed, 670 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c new file mode 100644 index 0000000000..5ea78986e6 --- /dev/null +++ b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c @@ -0,0 +1,670 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vpmu_counter_access - Test vPMU event counter access + * + * Copyright (c) 2023 Google LLC. + * + * This test checks if the guest can see the same number of the PMU event + * counters (PMCR_EL0.N) that userspace sets, if the guest can access + * those counters, and if the guest is prevented from accessing any + * other counters. + * It also checks if the userspace accesses to the PMU regsisters honor the + * PMCR.N value that's set for the guest. + * This test runs only when KVM_CAP_ARM_PMU_V3 is supported on the host. + */ +#include <kvm_util.h> +#include <processor.h> +#include <test_util.h> +#include <vgic.h> +#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 + +struct vpmu_vm { + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + int gic_fd; +}; + +static struct vpmu_vm vpmu_vm; + +struct pmreg_sets { + uint64_t set_reg_id; + uint64_t clr_reg_id; +}; + +#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 + * either directly reads/writes PMEV{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 PMEVTYPER<n>_EL0 */ + unsigned long (*read_typer)(int idx); + /* A function to be used to write PMEVTYPER<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 }, +}; + +/* + * Convert a pointer of pmc_accessor to an index in pmc_accessors[], + * assuming that the pointer is one of the entries in pmc_accessors[]. + */ +#define PMC_ACC_TO_IDX(acc) (acc - &pmc_accessors[0]) + +#define GUEST_ASSERT_BITMAP_REG(regname, mask, set_expected) \ +{ \ + uint64_t _tval = read_sysreg(regname); \ + \ + if (set_expected) \ + __GUEST_ASSERT((_tval & mask), \ + "tval: 0x%lx; mask: 0x%lx; set_expected: 0x%lx", \ + _tval, mask, set_expected); \ + else \ + __GUEST_ASSERT(!(_tval & mask), \ + "tval: 0x%lx; mask: 0x%lx; set_expected: 0x%lx", \ + _tval, mask, set_expected); \ +} + +/* + * Check if @mask bits in {PMCNTEN,PMINTEN,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(pmintenset_el1, mask, set_expected); + GUEST_ASSERT_BITMAP_REG(pmintenclr_el1, 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,PMINTEN,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, pmintenset_el1); + write_sysreg(test_bit, pmovsset_el0); + + /* The bit will be set only if the counter is implemented */ + pmcr_n = get_pmcr_n(read_sysreg(pmcr_el0)); + set_expected = (pmc_idx < pmcr_n) ? true : false; + } else { + write_sysreg(test_bit, pmcntenclr_el0); + write_sysreg(test_bit, pmintenclr_el1); + 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; + + /* Disable all PMCs and reset all PMCs to zero. */ + pmu_disable_reset(); + + /* + * Tests for reading/writing {PMCNTEN,PMINTEN,PMOVS}{SET,CLR}_EL1. + */ + + /* Make sure that the bit in those registers are set to 0 */ + test_bitmap_pmu_regs(pmc_idx, false); + /* Test if setting the bit in those registers works */ + test_bitmap_pmu_regs(pmc_idx, true); + /* Test if clearing the bit in those registers works */ + test_bitmap_pmu_regs(pmc_idx, false); + + /* + * Tests for reading/writing the event type register. + */ + + /* + * Set the event type register to an arbitrary value just for testing + * of reading/writing the register. + * Arm ARM 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(read_data == write_data, + "pmc_idx: 0x%lx; acc_idx: 0x%lx; read_data: 0x%lx; write_data: 0x%lx", + pmc_idx, PMC_ACC_TO_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 disabled and reset */ + __GUEST_ASSERT(read_data == 0, + "pmc_idx: 0x%lx; acc_idx: 0x%lx; read_data: 0x%lx", + pmc_idx, PMC_ACC_TO_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(read_data == write_data, + "pmc_idx: 0x%lx; acc_idx: 0x%lx; read_data: 0x%lx; write_data: 0x%lx", + pmc_idx, PMC_ACC_TO_IDX(acc), read_data, write_data); +} + +#define INVALID_EC (-1ul) +uint64_t expected_ec = INVALID_EC; + +static void guest_sync_handler(struct ex_regs *regs) +{ + uint64_t esr, ec; + + esr = read_sysreg(esr_el1); + ec = (esr >> ESR_EC_SHIFT) & ESR_EC_MASK; + + __GUEST_ASSERT(expected_ec == ec, + "PC: 0x%lx; ESR: 0x%lx; EC: 0x%lx; EC expected: 0x%lx", + regs->pc, esr, ec, expected_ec); + + /* skip the trapping instruction */ + regs->pc += 4; + + /* Use INVALID_EC to indicate an exception occurred */ + expected_ec = INVALID_EC; +} + +/* + * Run the given operation that should trigger an exception with the + * given exception class. The exception handler (guest_sync_handler) + * will reset op_end_addr to 0, expected_ec to INVALID_EC, and skip + * the instruction that trapped. + */ +#define TEST_EXCEPTION(ec, ops) \ +({ \ + GUEST_ASSERT(ec != INVALID_EC); \ + WRITE_ONCE(expected_ec, ec); \ + dsb(ish); \ + ops; \ + GUEST_ASSERT(expected_ec == INVALID_EC); \ +}) + +/* + * Tests for reading/writing registers for the unimplemented event counter + * specified by @pmc_idx (>= PMCR_EL0.N). + */ +static void test_access_invalid_pmc_regs(struct pmc_accessor *acc, int pmc_idx) +{ + /* + * Reading/writing the event count/type registers should cause + * an UNDEFINED exception. + */ + TEST_EXCEPTION(ESR_EC_UNKNOWN, acc->read_cntr(pmc_idx)); + TEST_EXCEPTION(ESR_EC_UNKNOWN, acc->write_cntr(pmc_idx, 0)); + TEST_EXCEPTION(ESR_EC_UNKNOWN, acc->read_typer(pmc_idx)); + TEST_EXCEPTION(ESR_EC_UNKNOWN, acc->write_typer(pmc_idx, 0)); + /* + * The bit corresponding to the (unimplemented) counter in + * {PMCNTEN,PMINTEN,PMOVS}{SET,CLR} registers should be RAZ. + */ + test_bitmap_pmu_regs(pmc_idx, 1); + test_bitmap_pmu_regs(pmc_idx, 0); +} + +/* + * 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, and + * if reading/writing PMU registers for implemented or unimplemented + * counters works as expected. + */ +static void guest_code(uint64_t expected_pmcr_n) +{ + uint64_t pmcr, pmcr_n, unimp_mask; + int i, pmc; + + __GUEST_ASSERT(expected_pmcr_n <= ARMV8_PMU_MAX_GENERAL_COUNTERS, + "Expected PMCR.N: 0x%lx; ARMv8 general counters: 0x%lx", + expected_pmcr_n, ARMV8_PMU_MAX_GENERAL_COUNTERS); + + pmcr = read_sysreg(pmcr_el0); + pmcr_n = get_pmcr_n(pmcr); + + /* Make sure that PMCR_EL0.N indicates the value userspace set */ + __GUEST_ASSERT(pmcr_n == expected_pmcr_n, + "Expected PMCR.N: 0x%lx, PMCR.N: 0x%lx", + expected_pmcr_n, pmcr_n); + + /* + * Make sure that (RAZ) bits corresponding to unimplemented event + * counters in {PMCNTEN,PMINTEN,PMOVS}{SET,CLR} registers are reset + * to zero. + * (NOTE: bits for implemented event counters are reset to UNKNOWN) + */ + unimp_mask = GENMASK_ULL(ARMV8_PMU_MAX_GENERAL_COUNTERS - 1, pmcr_n); + check_bitmap_pmu_regs(unimp_mask, false); + + /* + * Tests for reading/writing PMU registers for implemented counters. + * Use each combination of PMEV{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); + } + + /* + * Tests for reading/writing PMU registers for unimplemented counters. + * Use each combination of PMEV{CNTR,TYPER}<n>_EL0 accessor functions. + */ + for (i = 0; i < ARRAY_SIZE(pmc_accessors); i++) { + for (pmc = pmcr_n; pmc < ARMV8_PMU_MAX_GENERAL_COUNTERS; pmc++) + test_access_invalid_pmc_regs(&pmc_accessors[i], pmc); + } + + GUEST_DONE(); +} + +#define GICD_BASE_GPA 0x8000000ULL +#define GICR_BASE_GPA 0x80A0000ULL + +/* Create a VM that has one vCPU with PMUv3 configured. */ +static void create_vpmu_vm(void *guest_code) +{ + struct kvm_vcpu_init init; + uint8_t pmuver, ec; + uint64_t dfr0, irq = 23; + struct kvm_device_attr irq_attr = { + .group = KVM_ARM_VCPU_PMU_V3_CTRL, + .attr = KVM_ARM_VCPU_PMU_V3_IRQ, + .addr = (uint64_t)&irq, + }; + struct kvm_device_attr init_attr = { + .group = KVM_ARM_VCPU_PMU_V3_CTRL, + .attr = KVM_ARM_VCPU_PMU_V3_INIT, + }; + + /* The test creates the vpmu_vm multiple times. Ensure a clean state */ + memset(&vpmu_vm, 0, sizeof(vpmu_vm)); + + vpmu_vm.vm = vm_create(1); + vm_init_descriptor_tables(vpmu_vm.vm); + for (ec = 0; ec < ESR_EC_NUM; ec++) { + vm_install_sync_handler(vpmu_vm.vm, VECTOR_SYNC_CURRENT, ec, + guest_sync_handler); + } + + /* Create vCPU with PMUv3 */ + vm_ioctl(vpmu_vm.vm, KVM_ARM_PREFERRED_TARGET, &init); + init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3); + vpmu_vm.vcpu = aarch64_vcpu_add(vpmu_vm.vm, 0, &init, guest_code); + vcpu_init_descriptor_tables(vpmu_vm.vcpu); + vpmu_vm.gic_fd = vgic_v3_setup(vpmu_vm.vm, 1, 64, + GICD_BASE_GPA, GICR_BASE_GPA); + __TEST_REQUIRE(vpmu_vm.gic_fd >= 0, + "Failed to create vgic-v3, skipping"); + + /* Make sure that PMUv3 support is indicated in the ID register */ + vcpu_get_reg(vpmu_vm.vcpu, + KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &dfr0); + pmuver = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), dfr0); + TEST_ASSERT(pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF && + pmuver >= ID_AA64DFR0_EL1_PMUVer_IMP, + "Unexpected PMUVER (0x%x) on the vCPU with PMUv3", pmuver); + + /* Initialize vPMU */ + vcpu_ioctl(vpmu_vm.vcpu, KVM_SET_DEVICE_ATTR, &irq_attr); + vcpu_ioctl(vpmu_vm.vcpu, KVM_SET_DEVICE_ATTR, &init_attr); +} + +static void destroy_vpmu_vm(void) +{ + close(vpmu_vm.gic_fd); + kvm_vm_free(vpmu_vm.vm); +} + +static void run_vcpu(struct kvm_vcpu *vcpu, uint64_t pmcr_n) +{ + struct ucall uc; + + vcpu_args_set(vcpu, 1, pmcr_n); + vcpu_run(vcpu); + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_DONE: + break; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + break; + } +} + +static void test_create_vpmu_vm_with_pmcr_n(uint64_t pmcr_n, bool expect_fail) +{ + struct kvm_vcpu *vcpu; + uint64_t pmcr, pmcr_orig; + + create_vpmu_vm(guest_code); + vcpu = vpmu_vm.vcpu; + + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_PMCR_EL0), &pmcr_orig); + pmcr = pmcr_orig; + + /* + * Setting a larger value of PMCR.N should not modify the field, and + * return a success. + */ + set_pmcr_n(&pmcr, pmcr_n); + vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_PMCR_EL0), pmcr); + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_PMCR_EL0), &pmcr); + + if (expect_fail) + TEST_ASSERT(pmcr_orig == pmcr, + "PMCR.N modified by KVM to a larger value (PMCR: 0x%lx) for pmcr_n: 0x%lx\n", + pmcr, pmcr_n); + else + TEST_ASSERT(pmcr_n == get_pmcr_n(pmcr), + "Failed to update PMCR.N to %lu (received: %lu)\n", + pmcr_n, get_pmcr_n(pmcr)); +} + +/* + * Create a guest with one vCPU, set the PMCR_EL0.N for the vCPU to @pmcr_n, + * and run the test. + */ +static void run_access_test(uint64_t pmcr_n) +{ + uint64_t sp; + struct kvm_vcpu *vcpu; + struct kvm_vcpu_init init; + + pr_debug("Test with pmcr_n %lu\n", pmcr_n); + + test_create_vpmu_vm_with_pmcr_n(pmcr_n, false); + vcpu = vpmu_vm.vcpu; + + /* Save the initial sp to restore them later to run the guest again */ + vcpu_get_reg(vcpu, ARM64_CORE_REG(sp_el1), &sp); + + run_vcpu(vcpu, pmcr_n); + + /* + * Reset and re-initialize the vCPU, and run the guest code again to + * check if PMCR_EL0.N is preserved. + */ + vm_ioctl(vpmu_vm.vm, KVM_ARM_PREFERRED_TARGET, &init); + init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3); + aarch64_vcpu_setup(vcpu, &init); + vcpu_init_descriptor_tables(vcpu); + vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), sp); + vcpu_set_reg(vcpu, ARM64_CORE_REG(regs.pc), (uint64_t)guest_code); + + run_vcpu(vcpu, pmcr_n); + + destroy_vpmu_vm(); +} + +static struct pmreg_sets validity_check_reg_sets[] = { + PMREG_SET(SYS_PMCNTENSET_EL0, SYS_PMCNTENCLR_EL0), + PMREG_SET(SYS_PMINTENSET_EL1, SYS_PMINTENCLR_EL1), + PMREG_SET(SYS_PMOVSSET_EL0, SYS_PMOVSCLR_EL0), +}; + +/* + * Create a VM, and check if KVM handles the userspace accesses of + * the PMU register sets in @validity_check_reg_sets[] correctly. + */ +static void run_pmregs_validity_test(uint64_t pmcr_n) +{ + int i; + struct kvm_vcpu *vcpu; + uint64_t set_reg_id, clr_reg_id, reg_val; + uint64_t valid_counters_mask, max_counters_mask; + + test_create_vpmu_vm_with_pmcr_n(pmcr_n, false); + vcpu = vpmu_vm.vcpu; + + valid_counters_mask = get_counters_mask(pmcr_n); + max_counters_mask = get_counters_mask(ARMV8_PMU_MAX_COUNTERS); + + for (i = 0; i < ARRAY_SIZE(validity_check_reg_sets); i++) { + set_reg_id = validity_check_reg_sets[i].set_reg_id; + clr_reg_id = validity_check_reg_sets[i].clr_reg_id; + + /* + * Test if the 'set' and 'clr' variants of the registers + * are initialized based on the number of valid counters. + */ + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(set_reg_id), ®_val); + TEST_ASSERT((reg_val & (~valid_counters_mask)) == 0, + "Initial read of set_reg: 0x%llx has unimplemented counters enabled: 0x%lx\n", + KVM_ARM64_SYS_REG(set_reg_id), reg_val); + + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(clr_reg_id), ®_val); + TEST_ASSERT((reg_val & (~valid_counters_mask)) == 0, + "Initial read of clr_reg: 0x%llx has unimplemented counters enabled: 0x%lx\n", + KVM_ARM64_SYS_REG(clr_reg_id), reg_val); + + /* + * Using the 'set' variant, force-set the register to the + * max number of possible counters and test if KVM discards + * the bits for unimplemented counters as it should. + */ + vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(set_reg_id), max_counters_mask); + + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(set_reg_id), ®_val); + TEST_ASSERT((reg_val & (~valid_counters_mask)) == 0, + "Read of set_reg: 0x%llx has unimplemented counters enabled: 0x%lx\n", + KVM_ARM64_SYS_REG(set_reg_id), reg_val); + + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(clr_reg_id), ®_val); + TEST_ASSERT((reg_val & (~valid_counters_mask)) == 0, + "Read of clr_reg: 0x%llx has unimplemented counters enabled: 0x%lx\n", + KVM_ARM64_SYS_REG(clr_reg_id), reg_val); + } + + destroy_vpmu_vm(); +} + +/* + * Create a guest with one vCPU, and attempt to set the PMCR_EL0.N for + * the vCPU to @pmcr_n, which is larger than the host value. + * The attempt should fail as @pmcr_n is too big to set for the vCPU. + */ +static void run_error_test(uint64_t pmcr_n) +{ + pr_debug("Error test with pmcr_n %lu (larger than the host)\n", pmcr_n); + + test_create_vpmu_vm_with_pmcr_n(pmcr_n, true); + destroy_vpmu_vm(); +} + +/* + * Return the default number of implemented PMU event counters excluding + * the cycle counter (i.e. PMCR_EL0.N value) for the guest. + */ +static uint64_t get_pmcr_n_limit(void) +{ + uint64_t pmcr; + + create_vpmu_vm(guest_code); + vcpu_get_reg(vpmu_vm.vcpu, KVM_ARM64_SYS_REG(SYS_PMCR_EL0), &pmcr); + destroy_vpmu_vm(); + return get_pmcr_n(pmcr); +} + +int main(void) +{ + uint64_t i, pmcr_n; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3)); + + pmcr_n = get_pmcr_n_limit(); + for (i = 0; i <= pmcr_n; i++) { + run_access_test(i); + run_pmregs_validity_test(i); + } + + for (i = pmcr_n + 1; i < ARMV8_PMU_MAX_COUNTERS; i++) + run_error_test(i); + + return 0; +} |