[PATCH v4 10/11] KVM: riscv: selftests: Add sstc timer test

Haibo Xu
2023-12-12T09:22:07Z

Add a KVM selftests to validate the Sstc timer functionality.
The test was ported from arm64 arch timer test.

Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
---
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/aarch64/arch_timer.c | 12 +-
tools/testing/selftests/kvm/arch_timer.c | 10 +-
.../selftests/kvm/include/riscv/arch_timer.h | 71 ++++++++++++
.../selftests/kvm/include/riscv/processor.h | 10 ++
.../selftests/kvm/include/timer_test.h | 5 +-
.../testing/selftests/kvm/riscv/arch_timer.c | 107 ++++++++++++++++++
7 files changed, 206 insertions(+), 10 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/riscv/arch_timer.h
create mode 100644 tools/testing/selftests/kvm/riscv/arch_timer.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 671224c4b9e0..eb8071aba80a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -193,6 +193,7 @@ TEST_GEN_PROGS_s390x += rseq_test
TEST_GEN_PROGS_s390x += set_memory_region_test
TEST_GEN_PROGS_s390x += kvm_binary_stats_test

+TEST_GEN_PROGS_riscv += arch_timer
TEST_GEN_PROGS_riscv += demand_paging_test
TEST_GEN_PROGS_riscv += dirty_log_test
TEST_GEN_PROGS_riscv += guest_print_test
diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
index 6fb47ba07e5b..4b421d421c3f 100644
--- a/tools/testing/selftests/kvm/aarch64/arch_timer.c
+++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c
@@ -190,10 +190,14 @@ struct kvm_vm *test_vm_create(void)
vm_init_descriptor_tables(vm);
vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);

- if (!test_args.offset.reserved) {
- if (kvm_has_cap(KVM_CAP_COUNTER_OFFSET))
- vm_ioctl(vm, KVM_ARM_SET_COUNTER_OFFSET, &test_args.offset);
- else
+ if (!test_args.reserved) {
+ if (kvm_has_cap(KVM_CAP_COUNTER_OFFSET)) {
+ struct kvm_arm_counter_offset offset = {
+ .counter_offset = test_args.counter_offset,
+ .reserved = 0,
+ };
+ vm_ioctl(vm, KVM_ARM_SET_COUNTER_OFFSET, &offset);
+ } else
TEST_FAIL("no support for global offset\n");
}

diff --git a/tools/testing/selftests/kvm/arch_timer.c b/tools/testing/selftests/kvm/arch_timer.c
index 6e442dbcfc8b..60963fce16f2 100644
--- a/tools/testing/selftests/kvm/arch_timer.c
+++ b/tools/testing/selftests/kvm/arch_timer.c
@@ -34,7 +34,7 @@ struct test_args test_args = {
.nr_iter = NR_TEST_ITERS_DEF,
.timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
.migration_freq_ms = TIMER_TEST_MIGRATION_FREQ_MS,
- .offset = { .reserved = 1 },
+ .reserved = 1,
};

struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
@@ -73,6 +73,8 @@ static void *test_vcpu_run(void *arg)
TEST_FAIL("Unexpected guest exit\n");
}

+ pr_info("PASS(vCPU-%d).\n", vcpu_idx);
+
return NULL;
}

@@ -187,7 +189,7 @@ static void test_print_help(char *name)
TIMER_TEST_PERIOD_MS_DEF);
pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
TIMER_TEST_MIGRATION_FREQ_MS);
- pr_info("\t-o: Counter offset (in counter cycles, default: 0)\n");
+ pr_info("\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n");
pr_info("\t-h: print this help screen\n");
}

@@ -215,8 +217,8 @@ static bool parse_args(int argc, char *argv[])
test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
break;
case 'o':
- test_args.offset.counter_offset = strtol(optarg, NULL, 0);
- test_args.offset.reserved = 0;
+ test_args.counter_offset = strtol(optarg, NULL, 0);
+ test_args.reserved = 0;
break;
case 'h':
default:
diff --git a/tools/testing/selftests/kvm/include/riscv/arch_timer.h b/tools/testing/selftests/kvm/include/riscv/arch_timer.h
new file mode 100644
index 000000000000..23d4a0e0e1cd
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/riscv/arch_timer.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RISC-V Arch Timer(sstc) specific interface
+ *
+ * Copyright (c) 2023 Intel Corporation
+ */
+
+#ifndef SELFTEST_KVM_ARCH_TIMER_H
+#define SELFTEST_KVM_ARCH_TIMER_H
+
+#include <asm/csr.h>
+#include <asm/vdso/processor.h>
+
+static unsigned long timer_freq;
+
+#define msec_to_cycles(msec) \
+ ((timer_freq) * (uint64_t)(msec) / 1000)
+
+#define usec_to_cycles(usec) \
+ ((timer_freq) * (uint64_t)(usec) / 1000000)
+
+#define cycles_to_usec(cycles) \
+ ((uint64_t)(cycles) * 1000000 / (timer_freq))
+
+static inline uint64_t timer_get_cycles(void)
+{
+ return csr_read(CSR_TIME);
+}
+
+static inline void timer_set_cmp(uint64_t cval)
+{
+ csr_write(CSR_STIMECMP, cval);
+}
+
+static inline uint64_t timer_get_cmp(void)
+{
+ return csr_read(CSR_STIMECMP);
+}
+
+static inline void timer_irq_enable(void)
+{
+ csr_set(CSR_SIE, IE_TIE);
+}
+
+static inline void timer_irq_disable(void)
+{
+ csr_clear(CSR_SIE, IE_TIE);
+}
+
+static inline void timer_set_next_cmp_ms(uint32_t msec)
+{
+ uint64_t now_ct = timer_get_cycles();
+ uint64_t next_ct = now_ct + msec_to_cycles(msec);
+
+ timer_set_cmp(next_ct);
+}
+
+static inline void __delay(uint64_t cycles)
+{
+ uint64_t start = timer_get_cycles();
+
+ while ((timer_get_cycles() - start) < cycles)
+ cpu_relax();
+}
+
+static inline void udelay(unsigned long usec)
+{
+ __delay(usec_to_cycles(usec));
+}
+
+#endif /* SELFTEST_KVM_ARCH_TIMER_H */
diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
index bd27e1c67579..3e7f6b369a5e 100644
--- a/tools/testing/selftests/kvm/include/riscv/processor.h
+++ b/tools/testing/selftests/kvm/include/riscv/processor.h
@@ -158,4 +158,14 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
unsigned long arg3, unsigned long arg4,
unsigned long arg5);

+static inline void local_irq_enable(void)
+{
+ csr_set(CSR_SSTATUS, SR_SIE);
+}
+
+static inline void local_irq_disable(void)
+{
+ csr_clear(CSR_SSTATUS, SR_SIE);
+}
+
#endif /* SELFTEST_KVM_PROCESSOR_H */
diff --git a/tools/testing/selftests/kvm/include/timer_test.h b/tools/testing/selftests/kvm/include/timer_test.h
index 2234c513b510..968257b893a7 100644
--- a/tools/testing/selftests/kvm/include/timer_test.h
+++ b/tools/testing/selftests/kvm/include/timer_test.h
@@ -22,8 +22,9 @@ struct test_args {
int nr_iter;
int timer_period_ms;
int migration_freq_ms;
- /* TODO: Change arm specific type to a common one */
- struct kvm_arm_counter_offset offset;
+ /* Members of struct kvm_arm_counter_offset */
+ uint64_t counter_offset;
+ uint64_t reserved;
};

/* Shared variables between host and guest */
diff --git a/tools/testing/selftests/kvm/riscv/arch_timer.c b/tools/testing/selftests/kvm/riscv/arch_timer.c
new file mode 100644
index 000000000000..13bf184d1ff5
--- /dev/null
+++ b/tools/testing/selftests/kvm/riscv/arch_timer.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch_timer.c - Tests the riscv64 sstc timer IRQ functionality
+ *
+ * The test validates the sstc timer IRQs using vstimecmp registers.
+ * It's ported from the aarch64 arch_timer test.
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#define _GNU_SOURCE
+
+#include "arch_timer.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "timer_test.h"
+
+static int timer_irq = IRQ_S_TIMER;
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+ uint64_t xcnt, xcnt_diff_us, cmp;
+ unsigned int intid = regs->cause & ~CAUSE_IRQ_FLAG;
+ uint32_t cpu = guest_get_vcpuid();
+ struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+ timer_irq_disable();
+
+ xcnt = timer_get_cycles();
+ cmp = timer_get_cmp();
+ xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
+
+ /* Make sure we are dealing with the correct timer IRQ */
+ GUEST_ASSERT_EQ(intid, timer_irq);
+
+ __GUEST_ASSERT(xcnt >= cmp,
+ "xcnt = 0x%llx, cmp = 0x%llx, xcnt_diff_us = 0x%llx",
+ xcnt, cmp, xcnt_diff_us);
+
+ WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
+}
+
+static void guest_run(struct test_vcpu_shared_data *shared_data)
+{
+ uint32_t irq_iter, config_iter;
+
+ shared_data->nr_iter = 0;
+ shared_data->guest_stage = 0;
+
+ for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
+ /* Setup the next interrupt */
+ timer_set_next_cmp_ms(test_args.timer_period_ms);
+ shared_data->xcnt = timer_get_cycles();
+ timer_irq_enable();
+
+ /* Setup a timeout for the interrupt to arrive */
+ udelay(msecs_to_usecs(test_args.timer_period_ms) +
+ TIMER_TEST_ERR_MARGIN_US);
+
+ irq_iter = READ_ONCE(shared_data->nr_iter);
+ GUEST_ASSERT_EQ(config_iter + 1, irq_iter);
+ }
+}
+
+static void guest_code(void)
+{
+ uint32_t cpu = guest_get_vcpuid();
+ struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+ timer_irq_disable();
+ local_irq_enable();
+
+ guest_run(shared_data);
+
+ GUEST_DONE();
+}
+
+struct kvm_vm *test_vm_create(void)
+{
+ struct kvm_vm *vm;
+ int nr_vcpus = test_args.nr_vcpus;
+
+ vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
+ __TEST_REQUIRE(__vcpu_has_ext(vcpus[0], KVM_RISCV_ISA_EXT_SSTC),
+ "SSTC not available, skipping test\n");
+
+ vm_init_vector_tables(vm);
+ vm_install_interrupt_handler(vm, guest_irq_handler);
+
+ for (int i = 0; i < nr_vcpus; i++)
+ vcpu_init_vector_tables(vcpus[i]);
+
+ /* Initialize guest timer frequency. */
+ vcpu_get_reg(vcpus[0], RISCV_TIMER_REG(frequency), &timer_freq);
+ sync_global_to_guest(vm, timer_freq);
+ pr_debug("timer_freq: %lu\n", timer_freq);
+
+ /* Make all the test's cmdline args visible to the guest */
+ sync_global_to_guest(vm, test_args);
+
+ return vm;
+}
+
+void test_vm_cleanup(struct kvm_vm *vm)
+{
+ kvm_vm_free(vm);
+}
--
2.34.1