Extend the vPMU's vCPU migration test to validate chained events, and their overflow conditions. Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx> --- .../testing/selftests/kvm/aarch64/vpmu_test.c | 76 ++++++++++++++++++- 1 file changed, 75 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_test.c b/tools/testing/selftests/kvm/aarch64/vpmu_test.c index 066dc17fa3906..de725f4339ad5 100644 --- a/tools/testing/selftests/kvm/aarch64/vpmu_test.c +++ b/tools/testing/selftests/kvm/aarch64/vpmu_test.c @@ -23,7 +23,7 @@ * migrating the guest vCPU to random pCPUs in the system, and check * if the vPMU is still behaving as expected. The sub-tests include * testing basic functionalities such as basic counters behavior, - * overflow, and overflow interrupts. + * overflow, overflow interrupts, and chained events. * * Copyright (c) 2022 Google LLC. * @@ -61,6 +61,8 @@ #define PRE_OVERFLOW_32 (GENMASK(31, 0) - COUNT_TO_OVERFLOW + 1) #define PRE_OVERFLOW_64 (GENMASK(63, 0) - COUNT_TO_OVERFLOW + 1) +#define ALL_SET_64 GENMASK(63, 0) + #define GICD_BASE_GPA 0x8000000ULL #define GICR_BASE_GPA 0x80A0000ULL @@ -639,6 +641,75 @@ static void test_cycles_count(bool expect_count, bool test_overflow) pmu_disable_reset(); } +static void test_chained_count(int pmc_idx) +{ + int i, chained_pmc_idx; + struct pmc_accessor *acc; + uint64_t pmcr_n, cnt, cntr_val; + + /* The test needs at least two PMCs */ + pmcr_n = get_pmcr_n(); + GUEST_ASSERT_1(pmcr_n >= 2, pmcr_n); + + /* + * The chained counter's idx is always chained with (pmc_idx + 1). + * pmc_idx should be even as the chained event doesn't count on + * odd numbered counters. + */ + GUEST_ASSERT_1(pmc_idx % 2 == 0, pmc_idx); + + /* + * The max counter idx that the chained counter can occupy is + * (pmcr_n - 1), while the actual event sits on (pmcr_n - 2). + */ + chained_pmc_idx = pmc_idx + 1; + GUEST_ASSERT(chained_pmc_idx < pmcr_n); + + enable_counter(chained_pmc_idx); + pmu_irq_init(chained_pmc_idx); + + /* Configure the chained event using all the possible ways*/ + for (i = 0; i < ARRAY_SIZE(pmc_accessors); i++) { + acc = &pmc_accessors[i]; + + /* Test if the chained counter increments when the base event overflows */ + + cntr_val = 1; + acc->write_cntr(chained_pmc_idx, cntr_val); + acc->write_typer(chained_pmc_idx, ARMV8_PMUV3_PERFCTR_CHAIN); + + /* Chain the counter with pmc_idx that's configured for an overflow */ + test_instructions_count(pmc_idx, true, true); + + /* + * pmc_idx is also configured to run for all the ARRAY_SIZE(pmc_accessors) + * combinations. Hence, the chained chained_pmc_idx is expected to be + * cntr_val + ARRAY_SIZE(pmc_accessors). + */ + cnt = acc->read_cntr(chained_pmc_idx); + GUEST_ASSERT_4(cnt == cntr_val + ARRAY_SIZE(pmc_accessors), + pmc_idx, i, cnt, cntr_val + ARRAY_SIZE(pmc_accessors)); + + /* Test for the overflow of the chained counter itself */ + + cntr_val = ALL_SET_64; + acc->write_cntr(chained_pmc_idx, cntr_val); + + test_instructions_count(pmc_idx, true, true); + + /* + * At this point, an interrupt should've been fired for the chained + * counter (which validates the overflow bit), and the counter should've + * wrapped around to ARRAY_SIZE(pmc_accessors) - 1. + */ + cnt = acc->read_cntr(chained_pmc_idx); + GUEST_ASSERT_4(cnt == ARRAY_SIZE(pmc_accessors) - 1, + pmc_idx, i, cnt, ARRAY_SIZE(pmc_accessors)); + } + + pmu_irq_exit(chained_pmc_idx); +} + static void test_event_count(uint64_t event, int pmc_idx, bool expect_count) { switch (event) { @@ -665,6 +736,9 @@ static void test_basic_pmu_functionality(void) /* Test overflow with interrupts on generic and cycle counters */ test_instructions_count(0, true, true); test_cycles_count(true, true); + + /* Test chained events */ + test_chained_count(0); } /* -- 2.39.1.581.gbfd45094c4-goog