On Sat, Sep 02, 2023 at 08:59:30PM +0800, Haibo Xu wrote:
> Add a KVM selftest to validate the Sstc timer functionality.
> The test was ported from arm64 arch timer test.
>
> Signed-off-by: Haibo Xu <haibo1.xu@xxxxxxxxx>
> ---
> tools/testing/selftests/kvm/Makefile | 1 +
> tools/testing/selftests/kvm/arch_timer.c | 9 ++
> .../selftests/kvm/include/riscv/arch_timer.h | 80 +++++++++++
> .../selftests/kvm/include/riscv/processor.h | 10 ++
> .../selftests/kvm/include/timer_test.h | 6 +
> .../testing/selftests/kvm/riscv/arch_timer.c | 130 ++++++++++++++++++
> 6 files changed, 236 insertions(+)
> 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 01638027d059..7897d8051d8c 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -179,6 +179,7 @@ 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 += get-reg-list
> diff --git a/tools/testing/selftests/kvm/arch_timer.c b/tools/testing/selftests/kvm/arch_timer.c
> index 529024f58c98..691bd454e362 100644
> --- a/tools/testing/selftests/kvm/arch_timer.c
> +++ b/tools/testing/selftests/kvm/arch_timer.c
> @@ -66,8 +66,13 @@ static void *test_vcpu_run(void *arg)
> break;
> case UCALL_ABORT:
> sync_global_from_guest(vm, *shared_data);
> +#ifdef __aarch64__
> fprintf(stderr, "Guest assert failed, vcpu %u; stage; %u; iter: %u\n",
> vcpu_idx, shared_data->guest_stage, shared_data->nr_iter);
> +#else
> + fprintf(stderr, "Guest assert failed, vcpu %u; iter: %u\n",
> + vcpu_idx, shared_data->nr_iter);
> +#endif
We can avoid this #ifdef by just letting guest_stage output as zero for
riscv.
> REPORT_GUEST_ASSERT(uc);
> break;
> default:
> @@ -190,7 +195,9 @@ 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);
> +#ifdef __aarch64__
> pr_info("\t-o: Counter offset (in counter cycles, default: 0)\n");
> +#endif
We can avoid this and the next #ifdef by changing this pr_info to
"\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n"
> pr_info("\t-h: print this help screen\n");
> }
>
> @@ -217,10 +224,12 @@ static bool parse_args(int argc, char *argv[])
> case 'm':
> test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
> break;
> +#ifdef __aarch64__
> case 'o':
> test_args.offset.counter_offset = strtol(optarg, NULL, 0);
> test_args.offset.reserved = 0;
> break;
> +#endif
> case 'h':
> default:
> goto err;
> 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..897edcef8fc2
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/riscv/arch_timer.h
> @@ -0,0 +1,80 @@
> +// 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>
> +
> +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_cntct(void)
> +{
> + return csr_read(CSR_TIME);
> +}
> +
> +static inline void timer_set_cval(uint64_t cval)
> +{
> + csr_write(CSR_STIMECMP, cval);
> +}
> +
> +static inline uint64_t timer_get_cval(void)
> +{
> + return csr_read(CSR_STIMECMP);
> +}
The names in the above functions with cntct/cval are aarch64-isms. I'd
name the functions more explicitly: timer_get_cycles(), timer_set/get_cmp()
> +
> +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_cval_ms(uint32_t msec)
timer_set_next_cmp_ms()
> +{
> + uint64_t now_ct = timer_get_cntct();
> + uint64_t next_ct = now_ct + msec_to_cycles(msec);
> +
> + timer_set_cval(next_ct);
> +}
> +
> +static inline void cpu_relax(void)
> +{
> +#ifdef __riscv_zihintpause
> + asm volatile("pause" ::: "memory");
> +#else
> + /* Encoding of the pause instruction */
> + asm volatile(".4byte 0x100000F" ::: "memory");
> +#endif
> +}
> +
> +static inline void __delay(uint64_t cycles)
> +{
> + uint64_t start = timer_get_cntct();
> +
> + while ((timer_get_cntct() - 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 6087c8fc263a..c69f36302d41 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -161,4 +161,14 @@ 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 109e4d635627..091c05a14c93 100644
> --- a/tools/testing/selftests/kvm/include/timer_test.h
> +++ b/tools/testing/selftests/kvm/include/timer_test.h
> @@ -18,6 +18,7 @@
>
> #define msecs_to_usecs(msec) ((msec) * 1000LL)
>
> +#ifdef __aarch64__
> #define GICD_BASE_GPA 0x8000000ULL
> #define GICR_BASE_GPA 0x80A0000ULL
>
> @@ -28,6 +29,7 @@ enum guest_stage {
> GUEST_STAGE_PTIMER_TVAL,
> GUEST_STAGE_MAX,
> };
> +#endif
No need for this #ifdef, just move these aarch64 things to
aarch64/arch_timer.c
>
> /* Timer test cmdline parameters */
> struct test_args
> @@ -36,13 +38,17 @@ struct test_args
> int nr_iter;
> int timer_period_ms;
> int migration_freq_ms;
> +#ifdef __aarch64__
> struct kvm_arm_counter_offset offset;
> +#endif
test_args shouldn't have aarch64 stuff in it. We can change it to
uint64_t offset, which riscv won't use, and aarch64 will pack it
into a struct kvm_arm_counter_offset when it needs to use it.
> };
>
> /* Shared variables between host and guest */
> struct test_vcpu_shared_data {
> int nr_iter;
> +#ifdef __aarch64__
> enum guest_stage guest_stage;
> +#endif
No need for #ifdef. Each arch can define it's own guest_stage enum in its
own test file. riscv won't have any stages defined.
> uint64_t xcnt;
> };
>
> 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..c50a33c1e4f9
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/riscv/arch_timer.c
> @@ -0,0 +1,130 @@
> +// 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"
> +
> +extern struct test_args test_args;
> +extern struct kvm_vcpu *vcpus[];
> +extern struct test_vcpu_shared_data vcpu_shared_data[];
> +
> +static int timer_irq = IRQ_S_TIMER;
> +
> +static void
> +guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
> +{
> + timer_set_next_cval_ms(test_args.timer_period_ms);
> + shared_data->xcnt = timer_get_cntct();
> + timer_irq_enable();
> +}
> +
> +static void guest_validate_irq(unsigned int intid,
> + struct test_vcpu_shared_data *shared_data)
> +{
> + uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
Don't need to initialize xcnt and cval, they get overwritten right away.
(cval should be renamed to cmp)
> +
> + timer_irq_disable();
> + xcnt = timer_get_cntct();
> + cval = timer_get_cval();
> +
> + 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 >= cval,
> + "xcnt = 0x%llx, cval = 0x%llx, xcnt_diff_us = 0x%llx",
> + xcnt, cval, xcnt_diff_us);
> +
> + WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
> +}
> +
> +static void guest_irq_handler(struct ex_regs *regs)
> +{
> + 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];
> +
> + guest_validate_irq(intid, shared_data);
> +}
> +
> +static void guest_run(struct test_vcpu_shared_data *shared_data)
> +{
> + uint32_t irq_iter, config_iter;
> +
> + shared_data->nr_iter = 0;
> +
> + for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
> + /* Setup the next interrupt */
> + guest_configure_timer_action(shared_data);
> +
> + /* 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);
> + }
> +}
guest_run[_stage]() can be shared with aarch64, we just have a single
stage=0 for riscv.
> +
> +static void guest_code(void)
> +{
> + uint32_t cpu = guest_get_vcpuid();
> + struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
> +
> + local_irq_disable();
> + timer_irq_disable();
> + local_irq_enable();
I don't think we need to disable all interrupts when disabling the timer
interrupt.
> +
> + guest_run(shared_data);
> +
> + GUEST_DONE();
> +}
> +
> +static void test_init_timer_freq(struct kvm_vm *vm)
> +{
> + /* Timer frequency should be same for all the vCPUs, so query only vCPU-0 */
> + 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);
> +}
> +
> +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");
This will assert on get-one-reg rather than skip the test.
> +
> + 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]);
> +
> + test_init_timer_freq(vm);
> +
> + /* 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
>
Thanks,
drew
