[REPOST PATCH 03/16] KVM: selftests: aarch64: vPMU register test for implemented counters
Raghavendra Rao Ananta
rananta at google.com
Tue Feb 14 17:07:04 PST 2023
From: Reiji Watanabe <reijiw at google.com>
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 <reijiw at google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta at google.com>
---
.../kvm/aarch64/vpmu_counter_access.c | 350 +++++++++++++++++-
1 file changed, 347 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 7a4333f64daef..b6593eee2be3d 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_EL0.N) that userspace sets.
+ * counters (PMCR_EL0.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>
@@ -18,14 +19,348 @@
/* 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 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();
+}
+
+/*
+ * 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 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 },
+};
+
+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));
+}
+
+#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,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 = FIELD_GET(ARMV8_PMU_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, read_data_prev;
+
+ /* 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.
+ */
+
+ 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);
@@ -35,6 +370,15 @@ 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();
}
@@ -91,7 +435,7 @@ 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;
--
2.39.1.581.gbfd45094c4-goog
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