[PATCH v2 4/5] KVM: selftests: aarch64: Introduce pmu_event_filter_test
Shaoqin Huang
shahuang at redhat.com
Tue Nov 28 23:27:06 PST 2023
Introduce pmu_event_filter_test for arm64 platforms. The test configures
PMUv3 for a vCPU, and sets different pmu event filters for the vCPU, and
check if the guest can use those events which user allow and can't use
those events which use deny.
This test refactor the create_vpmu_vm() and make it a wrapper for
__create_vpmu_vm(), which allows some extra init code before
KVM_ARM_VCPU_PMU_V3_INIT.
And this test use the KVM_ARM_VCPU_PMU_V3_FILTER attribute to set the
pmu event filter in KVM. And choose to filter two common event
branches_retired and instructions_retired, and let guest use the two
events in pmu. And check if the result is expected.
Signed-off-by: Shaoqin Huang <shahuang at redhat.com>
---
tools/testing/selftests/kvm/Makefile | 1 +
.../kvm/aarch64/pmu_event_filter_test.c | 231 ++++++++++++++++++
.../selftests/kvm/include/aarch64/vpmu.h | 4 +
.../testing/selftests/kvm/lib/aarch64/vpmu.c | 14 +-
4 files changed, 248 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index b60852c222ac..5f126e1a1dbf 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -155,6 +155,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
+TEST_GEN_PROGS_aarch64 += aarch64/pmu_event_filter_test
TEST_GEN_PROGS_aarch64 += aarch64/psci_test
TEST_GEN_PROGS_aarch64 += aarch64/set_id_regs
TEST_GEN_PROGS_aarch64 += aarch64/smccc_filter
diff --git a/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
new file mode 100644
index 000000000000..0e652fbdb37a
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * pmu_event_filter_test - Test user limit pmu event for guest.
+ *
+ * Copyright (c) 2023 Red Hat, Inc.
+ *
+ * This test checks if the guest only see the limited pmu event that userspace
+ * sets, if the guest can use those events which user allow, and if the guest
+ * can't use those events which user deny.
+ * This test runs only when KVM_CAP_ARM_PMU_V3, KVM_ARM_VCPU_PMU_V3_FILTER
+ * is supported on the host.
+ */
+#include <kvm_util.h>
+#include <processor.h>
+#include <vgic.h>
+#include <vpmu.h>
+#include <test_util.h>
+#include <perf/arm_pmuv3.h>
+
+struct {
+ uint64_t branches_retired;
+ uint64_t instructions_retired;
+} pmc_results;
+
+static struct vpmu_vm *vpmu_vm;
+static uint64_t pmceid0;
+
+#define FILTER_NR 10
+
+struct test_desc {
+ const char *name;
+ void (*check_result)(void);
+ struct kvm_pmu_event_filter filter[FILTER_NR];
+};
+
+#define __DEFINE_FILTER(base, num, act) \
+ ((struct kvm_pmu_event_filter) { \
+ .base_event = base, \
+ .nevents = num, \
+ .action = act, \
+ })
+
+#define DEFINE_FILTER(base, act) __DEFINE_FILTER(base, 1, act)
+
+#define EMPTY_FILTER { 0 }
+
+#define SW_INCR 0x0
+#define INST_RETIRED 0x8
+#define BR_RETIRED 0x21
+
+#define NUM_BRANCHES 10
+
+static void run_and_measure_loop(void)
+{
+ asm volatile(
+ " mov x10, %[loop]\n"
+ "1: sub x10, x10, #1\n"
+ " cmp x10, #0x0\n"
+ " b.gt 1b\n"
+ :
+ : [loop] "r" (NUM_BRANCHES)
+ : "x10", "cc");
+}
+
+static void guest_code(void)
+{
+ uint64_t pmcr = read_sysreg(pmcr_el0);
+
+ pmu_disable_reset();
+
+ write_pmevtypern(0, BR_RETIRED);
+ write_pmevtypern(1, INST_RETIRED);
+ enable_counter(0);
+ enable_counter(1);
+ write_sysreg(pmcr | ARMV8_PMU_PMCR_E, pmcr_el0);
+
+ run_and_measure_loop();
+
+ write_sysreg(pmcr, pmcr_el0);
+
+ pmc_results.branches_retired = read_sysreg(pmevcntr0_el0);
+ pmc_results.instructions_retired = read_sysreg(pmevcntr1_el0);
+
+ GUEST_DONE();
+}
+
+static void guest_get_pmceid0(void)
+{
+ uint64_t pmceid0 = read_sysreg(pmceid0_el0);
+
+ GUEST_PRINTF("%lx\n", pmceid0);
+
+ GUEST_DONE();
+}
+
+static void pmu_event_filter_init(struct vpmu_vm *vm, void *arg)
+{
+ struct kvm_device_attr attr = {
+ .group = KVM_ARM_VCPU_PMU_V3_CTRL,
+ .attr = KVM_ARM_VCPU_PMU_V3_FILTER,
+ };
+ struct kvm_pmu_event_filter *filter = (struct kvm_pmu_event_filter *)arg;
+
+ while (filter && filter->nevents != 0) {
+ attr.addr = (uint64_t)filter;
+ vcpu_ioctl(vm->vcpu, KVM_SET_DEVICE_ATTR, &attr);
+ filter++;
+ }
+}
+
+static void create_vpmu_vm_with_filter(void *guest_code,
+ struct kvm_pmu_event_filter *filter)
+{
+ vpmu_vm = __create_vpmu_vm(guest_code, pmu_event_filter_init, filter);
+}
+
+static void run_vcpu(struct kvm_vcpu *vcpu)
+{
+ struct ucall uc;
+
+ while (1) {
+ vcpu_run(vcpu);
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_DONE:
+ return;
+ case UCALL_PRINTF:
+ pmceid0 = strtoll(uc.buffer, NULL, 16);
+ break;
+ default:
+ TEST_FAIL("Unknown ucall %lu", uc.cmd);
+ }
+ }
+}
+
+static void check_pmc_counting(void)
+{
+ uint64_t br = pmc_results.branches_retired;
+ uint64_t ir = pmc_results.instructions_retired;
+
+ TEST_ASSERT(br && br == NUM_BRANCHES, "Branch instructions retired = "
+ "%lu (expected %u)", br, NUM_BRANCHES);
+ TEST_ASSERT(ir, "Instructions retired = %lu (expected > 0)", ir);
+}
+
+static void check_pmc_not_counting(void)
+{
+ uint64_t br = pmc_results.branches_retired;
+ uint64_t ir = pmc_results.instructions_retired;
+
+ TEST_ASSERT(!br, "Branch instructions retired = %lu (expected 0)", br);
+ TEST_ASSERT(!ir, "Instructions retired = %lu (expected 0)", ir);
+}
+
+static void run_vcpu_and_sync_pmc_results(void)
+{
+ memset(&pmc_results, 0, sizeof(pmc_results));
+ sync_global_to_guest(vpmu_vm->vm, pmc_results);
+
+ run_vcpu(vpmu_vm->vcpu);
+
+ sync_global_from_guest(vpmu_vm->vm, pmc_results);
+}
+
+static void run_test(struct test_desc *t)
+{
+ pr_debug("Test: %s\n", t->name);
+
+ create_vpmu_vm_with_filter(guest_code, t->filter);
+
+ run_vcpu_and_sync_pmc_results();
+
+ t->check_result();
+
+ destroy_vpmu_vm(vpmu_vm);
+}
+
+static struct test_desc tests[] = {
+ {"without_filter", check_pmc_counting, { EMPTY_FILTER }},
+ {"member_allow_filter", check_pmc_counting,
+ {DEFINE_FILTER(SW_INCR, 0), DEFINE_FILTER(INST_RETIRED, 0),
+ DEFINE_FILTER(BR_RETIRED, 0), EMPTY_FILTER}},
+ {"member_deny_filter", check_pmc_not_counting,
+ {DEFINE_FILTER(SW_INCR, 1), DEFINE_FILTER(INST_RETIRED, 1),
+ DEFINE_FILTER(BR_RETIRED, 1), EMPTY_FILTER}},
+ {"not_member_deny_filter", check_pmc_counting,
+ {DEFINE_FILTER(SW_INCR, 1), EMPTY_FILTER}},
+ {"not_member_allow_filter", check_pmc_not_counting,
+ {DEFINE_FILTER(SW_INCR, 0), EMPTY_FILTER}},
+ { 0 }
+};
+
+static void for_each_test(void)
+{
+ struct test_desc *t;
+
+ for (t = &tests[0]; t->name; t++)
+ run_test(t);
+}
+
+static bool kvm_supports_pmu_event_filter(void)
+{
+ int r;
+
+ vpmu_vm = create_vpmu_vm(guest_code);
+
+ r = __kvm_has_device_attr(vpmu_vm->vcpu->fd, KVM_ARM_VCPU_PMU_V3_CTRL,
+ KVM_ARM_VCPU_PMU_V3_FILTER);
+
+ destroy_vpmu_vm(vpmu_vm);
+ return !r;
+}
+
+static bool host_pmu_supports_events(void)
+{
+ vpmu_vm = create_vpmu_vm(guest_get_pmceid0);
+
+ run_vcpu(vpmu_vm->vcpu);
+
+ destroy_vpmu_vm(vpmu_vm);
+
+ return pmceid0 & (BR_RETIRED | INST_RETIRED);
+}
+
+int main(void)
+{
+ TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3));
+ TEST_REQUIRE(kvm_supports_pmu_event_filter());
+ TEST_REQUIRE(host_pmu_supports_events());
+
+ for_each_test();
+}
diff --git a/tools/testing/selftests/kvm/include/aarch64/vpmu.h b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
index 644dae3814b5..f103d0824f8a 100644
--- a/tools/testing/selftests/kvm/include/aarch64/vpmu.h
+++ b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
@@ -18,6 +18,10 @@ struct vpmu_vm {
int gic_fd;
};
+struct vpmu_vm *__create_vpmu_vm(void *guest_code,
+ void (*init_pmu)(struct vpmu_vm *vm, void *arg),
+ void *arg);
+
struct vpmu_vm *create_vpmu_vm(void *guest_code);
void destroy_vpmu_vm(struct vpmu_vm *vpmu_vm);
diff --git a/tools/testing/selftests/kvm/lib/aarch64/vpmu.c b/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
index b3de8fdc555e..76ea03d607f1 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
@@ -7,8 +7,9 @@
#include <vpmu.h>
#include <perf/arm_pmuv3.h>
-/* Create a VM that has one vCPU with PMUv3 configured. */
-struct vpmu_vm *create_vpmu_vm(void *guest_code)
+struct vpmu_vm *__create_vpmu_vm(void *guest_code,
+ void (*init_pmu)(struct vpmu_vm *vm, void *arg),
+ void *arg)
{
struct kvm_vcpu_init init;
uint8_t pmuver;
@@ -50,12 +51,21 @@ struct vpmu_vm *create_vpmu_vm(void *guest_code)
"Unexpected PMUVER (0x%x) on the vCPU with PMUv3", pmuver);
/* Initialize vPMU */
+ if (init_pmu)
+ init_pmu(vpmu_vm, arg);
+
vcpu_ioctl(vpmu_vm->vcpu, KVM_SET_DEVICE_ATTR, &irq_attr);
vcpu_ioctl(vpmu_vm->vcpu, KVM_SET_DEVICE_ATTR, &init_attr);
return vpmu_vm;
}
+/* Create a VM that has one vCPU with PMUv3 configured. */
+struct vpmu_vm *create_vpmu_vm(void *guest_code)
+{
+ return __create_vpmu_vm(guest_code, NULL, NULL);
+}
+
void destroy_vpmu_vm(struct vpmu_vm *vpmu_vm)
{
close(vpmu_vm->gic_fd);
--
2.40.1
More information about the linux-arm-kernel
mailing list