Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 9 Apr 2024 16:47:51 -0700 | Subject | Re: [PATCH v5 22/22] KVM: riscv: selftests: Add a test for counter overflow | From | Atish Patra <> |
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On 4/5/24 06:23, Andrew Jones wrote: > On Wed, Apr 03, 2024 at 01:04:51AM -0700, Atish Patra wrote: >> Add a test for verifying overflow interrupt. Currently, it relies on >> overflow support on cycle/instret events. This test works for cycle/ >> instret events which support sampling via hpmcounters on the platform. >> There are no ISA extensions to detect if a platform supports that. Thus, >> this test will fail on platform with virtualization but doesn't >> support overflow on these two events. > > Maybe we should give the user a command line option to disable this test > in case the platform they're testing doesn't support it but they want to > run the rest of the tests without getting a FAIL. >
Sure. I will add that option.
>> >> Reviewed-by: Anup Patel <anup@brainfault.org> >> Signed-off-by: Atish Patra <atishp@rivosinc.com> >> --- >> .../selftests/kvm/riscv/sbi_pmu_test.c | 114 ++++++++++++++++++ >> 1 file changed, 114 insertions(+) >> >> diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c >> index 7d195be5c3d9..451db956b885 100644 >> --- a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c >> +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c >> @@ -14,6 +14,7 @@ >> #include "test_util.h" >> #include "processor.h" >> #include "sbi.h" >> +#include "arch_timer.h" >> >> /* Maximum counters(firmware + hardware) */ >> #define RISCV_MAX_PMU_COUNTERS 64 >> @@ -24,6 +25,9 @@ union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS]; >> static void *snapshot_gva; >> static vm_paddr_t snapshot_gpa; >> >> +static int vcpu_shared_irq_count; >> +static int counter_in_use; >> + >> /* Cache the available counters in a bitmask */ >> static unsigned long counter_mask_available; >> >> @@ -117,6 +121,31 @@ static void guest_illegal_exception_handler(struct ex_regs *regs) >> regs->epc += 4; >> } >> >> +static void guest_irq_handler(struct ex_regs *regs) >> +{ >> + unsigned int irq_num = regs->cause & ~CAUSE_IRQ_FLAG; >> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva; >> + unsigned long overflown_mask; >> + unsigned long counter_val = 0; >> + >> + /* Validate that we are in the correct irq handler */ >> + GUEST_ASSERT_EQ(irq_num, IRQ_PMU_OVF); >> + >> + /* Stop all counters first to avoid further interrupts */ >> + stop_counter(counter_in_use, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); >> + >> + csr_clear(CSR_SIP, BIT(IRQ_PMU_OVF)); >> + >> + overflown_mask = READ_ONCE(snapshot_data->ctr_overflow_mask); >> + GUEST_ASSERT(overflown_mask & 0x01); >> + >> + WRITE_ONCE(vcpu_shared_irq_count, vcpu_shared_irq_count+1); >> + >> + counter_val = READ_ONCE(snapshot_data->ctr_values[0]); >> + /* Now start the counter to mimick the real driver behavior */ >> + start_counter(counter_in_use, SBI_PMU_START_FLAG_SET_INIT_VALUE, counter_val); >> +} >> + >> static unsigned long get_counter_index(unsigned long cbase, unsigned long cmask, >> unsigned long cflags, >> unsigned long event) >> @@ -276,6 +305,33 @@ static void test_pmu_event_snapshot(unsigned long event) >> stop_reset_counter(counter, 0); >> } >> >> +static void test_pmu_event_overflow(unsigned long event) >> +{ >> + unsigned long counter; >> + unsigned long counter_value_post; >> + unsigned long counter_init_value = ULONG_MAX - 10000; >> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva; >> + >> + counter = get_counter_index(0, counter_mask_available, 0, event); >> + counter_in_use = counter; >> + >> + /* The counter value is updated w.r.t relative index of cbase passed to start/stop */ >> + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value); >> + start_counter(counter, SBI_PMU_START_FLAG_INIT_SNAPSHOT, 0); >> + dummy_func_loop(10000); >> + udelay(msecs_to_usecs(2000)); >> + /* irq handler should have stopped the counter */ >> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); >> + >> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]); >> + /* The counter value after stopping should be less the init value due to overflow */ >> + __GUEST_ASSERT(counter_value_post < counter_init_value, >> + "counter_value_post %lx counter_init_value %lx for counter\n", >> + counter_value_post, counter_init_value); >> + >> + stop_reset_counter(counter, 0); >> +} >> + >> static void test_invalid_event(void) >> { >> struct sbiret ret; >> @@ -366,6 +422,34 @@ static void test_pmu_events_snaphost(void) >> GUEST_DONE(); >> } >> >> +static void test_pmu_events_overflow(void) >> +{ >> + int num_counters = 0; >> + >> + /* Verify presence of SBI PMU and minimum requrired SBI version */ >> + verify_sbi_requirement_assert(); >> + >> + snapshot_set_shmem(snapshot_gpa, 0); >> + csr_set(CSR_IE, BIT(IRQ_PMU_OVF)); >> + local_irq_enable(); >> + >> + /* Get the counter details */ >> + num_counters = get_num_counters(); >> + update_counter_info(num_counters); >> + >> + /* >> + * Qemu supports overflow for cycle/instruction. >> + * This test may fail on any platform that do not support overflow for these two events. >> + */ >> + test_pmu_event_overflow(SBI_PMU_HW_CPU_CYCLES); >> + GUEST_ASSERT_EQ(vcpu_shared_irq_count, 1); >> + >> + test_pmu_event_overflow(SBI_PMU_HW_INSTRUCTIONS); >> + GUEST_ASSERT_EQ(vcpu_shared_irq_count, 2); >> + >> + GUEST_DONE(); >> +} >> + >> static void run_vcpu(struct kvm_vcpu *vcpu) >> { >> struct ucall uc; >> @@ -451,6 +535,33 @@ static void test_vm_events_snapshot_test(void *guest_code) >> test_vm_destroy(vm); >> } >> >> +static void test_vm_events_overflow(void *guest_code) >> +{ >> + struct kvm_vm *vm = NULL; >> + struct kvm_vcpu *vcpu; >> + >> + vm = vm_create_with_one_vcpu(&vcpu, guest_code); >> + __TEST_REQUIRE(__vcpu_has_sbi_ext(vcpu, KVM_RISCV_SBI_EXT_PMU), >> + "SBI PMU not available, skipping test"); >> + >> + __TEST_REQUIRE(__vcpu_has_isa_ext(vcpu, KVM_RISCV_ISA_EXT_SSCOFPMF), >> + "Sscofpmf is not available, skipping overflow test"); >> + >> + > > extra blank line here >
Fixed.
>> + test_vm_setup_snapshot_mem(vm, vcpu); >> + vm_init_vector_tables(vm); >> + vm_install_interrupt_handler(vm, guest_irq_handler); >> + >> + vcpu_init_vector_tables(vcpu); >> + /* Initialize guest timer frequency. */ >> + vcpu_get_reg(vcpu, RISCV_TIMER_REG(frequency), &timer_freq); >> + sync_global_to_guest(vm, timer_freq); >> + >> + run_vcpu(vcpu); >> + >> + test_vm_destroy(vm); >> +} >> + >> int main(void) >> { >> pr_info("SBI PMU basic test : starting\n"); >> @@ -463,5 +574,8 @@ int main(void) >> test_vm_events_snapshot_test(test_pmu_events_snaphost); >> pr_info("SBI PMU event verification with snapshot test : PASS\n"); >> >> + test_vm_events_overflow(test_pmu_events_overflow); >> + pr_info("SBI PMU event verification with overflow test : PASS\n"); >> + >> return 0; >> } >> -- >> 2.34.1 >> > > Other than the command line option idea, > > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > > Thanks, > drew
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