Test that the KVM_{GET,SET}_SYSTEM_COUNTER_STATE ioctls correctly
configure the guest's view of the virtual counter-timer (CNTVCT_EL0).
Reviewed-by: Jing Zhang <jingzhangos@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
Reviewed-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
---
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/aarch64/processor.h | 24 +++
.../selftests/kvm/system_counter_state_test.c | 199 ++++++++++++++++++
4 files changed, 225 insertions(+)
create mode 100644 tools/testing/selftests/kvm/system_counter_state_test.c
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index bd83158e0e0b..1a5782d8a0d4 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -34,6 +34,7 @@
/x86_64/xen_vmcall_test
/x86_64/xss_msr_test
/x86_64/vmx_pmu_msrs_test
+/system_counter_state_test
/demand_paging_test
/dirty_log_test
/dirty_log_perf_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index e439d027939d..b14f16dc954a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -80,6 +80,7 @@ TEST_GEN_PROGS_x86_64 += steal_time
TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list-sve
TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
+TEST_GEN_PROGS_aarch64 += system_counter_state_test
TEST_GEN_PROGS_aarch64 += demand_paging_test
TEST_GEN_PROGS_aarch64 += dirty_log_test
TEST_GEN_PROGS_aarch64 += dirty_log_perf_test
diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index b7fa0c8551db..48c964ce62ff 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -52,6 +52,30 @@ static inline void set_reg(struct kvm_vm *vm, uint32_t vcpuid, uint64_t id, uint
vcpu_ioctl(vm, vcpuid, KVM_SET_ONE_REG, ®);
}
+static inline uint64_t read_cntpct_ordered(void)
+{
+ uint64_t r;
+
+ asm volatile("isb\n\t"
+ "mrs %0, cntpct_el0\n\t"
+ "isb\n\t"
+ : "=r"(r));
+
+ return r;
+}
+
+static inline uint64_t read_cntvct_ordered(void)
+{
+ uint64_t r;
+
+ asm volatile("isb\n\t"
+ "mrs %0, cntvct_el0\n\t"
+ "isb\n\t"
+ : "=r"(r));
+
+ return r;
+}
+
void aarch64_vcpu_setup(struct kvm_vm *vm, int vcpuid, struct kvm_vcpu_init *init);
void aarch64_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_vcpu_init *init, void *guest_code);
diff --git a/tools/testing/selftests/kvm/system_counter_state_test.c b/tools/testing/selftests/kvm/system_counter_state_test.c
new file mode 100644
index 000000000000..059971f6cb87
--- /dev/null
+++ b/tools/testing/selftests/kvm/system_counter_state_test.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * system_counter_state_test.c -- suite of tests for correctness of
+ * KVM_{GET,SET}_SYSTEM_COUNTER_STATE ioctls.
+ *
+ * Copyright (c) 2021, Google LLC.
+ */
+#define _GNU_SOURCE
+#include <asm/kvm.h>
+#include <linux/kvm.h>
+#include <stdint.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+
+#define VCPU_ID 0
+
+#ifdef __aarch64__
+
+enum counter {
+ VIRTUAL,
+ PHYSICAL,
+};
+
+static char *counter_name(enum counter counter)
+{
+ switch (counter) {
+ case VIRTUAL:
+ return "virtual";
+ case PHYSICAL:
+ return "physical";
+ default:
+ TEST_ASSERT(false, "unrecognized counter: %d", counter);
+ }
+
+ /* never reached */
+ return NULL;
+}
+
+struct system_counter_state_test {
+ enum counter counter;
+ struct kvm_system_counter_state state;
+};
+
+static struct system_counter_state_test test_cases[] = {
+ {
+ .counter = VIRTUAL,
+ .state = {
+ .cntvoff = 0
+ }
+ },
+ {
+ .counter = VIRTUAL,
+ .state = {
+ .cntvoff = 1000000
+ }
+ },
+ {
+ .counter = VIRTUAL,
+ .state = {
+ .cntvoff = -1
+ }
+ },
+};
+
+static void pr_test(struct system_counter_state_test *test)
+{
+ pr_info("counter: %s, cntvoff: %lld\n", counter_name(test->counter), test->state.cntvoff);
+}
+
+static struct kvm_system_counter_state *
+get_system_counter_state(struct system_counter_state_test *test)
+{
+ return &test->state;
+}
+
+/*
+ * Reads the guest counter-timer under test.
+ */
+static uint64_t guest_read_counter(struct system_counter_state_test *test)
+{
+ switch (test->counter) {
+ case PHYSICAL:
+ return read_cntpct_ordered();
+ case VIRTUAL:
+ return read_cntvct_ordered();
+ default:
+ GUEST_ASSERT(0);
+ }
+
+ /* never reached */
+ return -1;
+}
+
+/*
+ * Reads the host physical counter-timer and transforms it into a guest value
+ * according to the kvm_system_counter_state structure.
+ */
+static uint64_t host_read_guest_counter(struct system_counter_state_test *test)
+{
+ uint64_t r;
+
+ r = read_cntvct_ordered();
+ switch (test->counter) {
+ case VIRTUAL:
+ r -= test->state.cntvoff;
+ break;
+ default:
+ TEST_ASSERT(false, "unrecognized counter: %d", test->counter);
+ }
+
+ return r;
+}
+
+#else
+#error test not implemented for architecture being built!
+#endif
+
+static void guest_main(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
+ struct system_counter_state_test *test = &test_cases[i];
+
+ GUEST_SYNC(guest_read_counter(test));
+ }
+
+ GUEST_DONE();
+}
+
+static bool enter_guest(struct kvm_vm *vm, uint64_t *guest_counter)
+{
+ struct ucall uc;
+
+ vcpu_ioctl(vm, VCPU_ID, KVM_RUN, NULL);
+
+ switch (get_ucall(vm, VCPU_ID, &uc)) {
+ case UCALL_DONE:
+ return true;
+ case UCALL_SYNC:
+ if (guest_counter)
+ *guest_counter = uc.args[1];
+ break;
+ case UCALL_ABORT:
+ TEST_ASSERT(false, "%s at %s:%ld", (const char *)uc.args[0],
+ __FILE__, uc.args[1]);
+ break;
+ default:
+ TEST_ASSERT(false, "unexpected exit: %s",
+ exit_reason_str(vcpu_state(vm, VCPU_ID)->exit_reason));
+ break;
+ }
+
+ /* more work to do in the guest */
+ return false;
+}
+
+static void run_tests(struct kvm_vm *vm)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
+ struct system_counter_state_test *test = &test_cases[i];
+ uint64_t start, end, obs;
+
+ pr_info("test %d: ", i);
+ pr_test(test);
+
+ vcpu_ioctl(vm, VCPU_ID, KVM_SET_SYSTEM_COUNTER_STATE,
+ get_system_counter_state(test));
+
+ start = host_read_guest_counter(test);
+ TEST_ASSERT(!enter_guest(vm, &obs), "guest completed unexpectedly");
+ end = host_read_guest_counter(test);
+
+ TEST_ASSERT(start < obs && obs < end,
+ "guest counter value (%ld) outside expected bounds: (%ld, %ld)",
+ obs, start, end);
+ }
+
+ TEST_ASSERT(enter_guest(vm, NULL), "guest didn't run to completion");
+}
+
+int main(void)
+{
+ struct kvm_vm *vm;
+
+ if (!kvm_check_cap(KVM_CAP_SYSTEM_COUNTER_STATE)) {
+ print_skip("KVM_CAP_SYSTEM_COUNTER_STATE not supported");
+ exit(KSFT_SKIP);
+ }
+
+ vm = vm_create_default(0, 0, guest_main);
+ ucall_init(vm, NULL);
+ run_tests(vm);
+ kvm_vm_free(vm);
+}
--
2.32.0.rc1.229.g3e70b5a671-goog
