| Message ID | d2b3c53537fef3f0a2d27d8be663a64123d4bc3c.1693659382.git.haibo1.xu@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | RISCV: Add kvm Sstc timer selftest | expand |
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@intel.com> > --- > 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
On Mon, Sep 4, 2023 at 10:58 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > 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@intel.com> > > --- > > 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. > > + * > guest_run[_stage]() can be shared with aarch64, we just have a single > stage=0 for riscv. > Yes, we can. But if we share the guest_run[_stage]() by moving it to kvm/arch_timer.c or kvm/include/timer_test.h, we need to declare extra sub-functions somewhere in a header file(etc. guest_configure_timer_action()). > > + > > +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. > There is no local_irq_disable() protection during the initial debug phase, but the test always fail with below error messages: Guest assert failed, vcpu 0; stage; 0; iter: 0 ==== Test Assertion Failure ==== riscv/arch_timer.c:78: config_iter + 1 == irq_iter pid=585 tid=586 errno=4 - Interrupted system call (stack trace empty) 0x1 != 0x0 (config_iter + 1 != irq_iter) To be frank, I am not quite sure why the local_irq_disable/enable() matters. One possible reason may be some timer irq was triggered before we set up the timecmp register. > > + > > + guest_run(shared_data); > > + > > + GUEST_DONE(); > > +} > > + > > +void test_vm_cleanup(struct kvm_vm *vm) > > +{ > > + kvm_vm_free(vm); > > +} > > -- > > 2.34.1 > > > > Thanks, > drew
On Thu, Sep 07, 2023 at 12:20:29PM +0800, Haibo Xu wrote: > On Mon, Sep 4, 2023 at 10:58 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > > > 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@intel.com> > > > --- > > > > 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. > > > + * > > > guest_run[_stage]() can be shared with aarch64, we just have a single > > stage=0 for riscv. > > > > Yes, we can. But if we share the guest_run[_stage]() by moving it to > kvm/arch_timer.c > or kvm/include/timer_test.h, we need to declare extra sub-functions > somewhere in a > header file(etc. guest_configure_timer_action()). OK, whatever balances the reduction of duplicate code and avoidance of exporting helper functions. BTW, riscv may not need/want all the same helper functions as aarch64. Anyway, I guess I'll see how the next version turns out. > > > > + > > > +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. > > > > There is no local_irq_disable() protection during the initial debug > phase, but the test always > fail with below error messages: > > Guest assert failed, vcpu 0; stage; 0; iter: 0 > ==== Test Assertion Failure ==== > riscv/arch_timer.c:78: config_iter + 1 == irq_iter > pid=585 tid=586 errno=4 - Interrupted system call > (stack trace empty) > 0x1 != 0x0 (config_iter + 1 != irq_iter) > > To be frank, I am not quite sure why the local_irq_disable/enable() matters. > One possible reason may be some timer irq was triggered before we set up the > timecmp register. We should ensure we know the exact, expected state of the vcpu before, during, and after the test. If a state doesn't match expectations, then the test should assert and we should go investigate the test code to see if setup/checking is correct. If it is, then we've found a bug in KVM that we need to go investigate. For Sstc, a pending timer interrupt completely depends on stimecmp, so we need to watch that closely. Take a look at the attached simple timer test I pulled together to illustrate how stimecmp, timer interrupt enable, and all interrupt enable interact. You may want to use it to help port the arch_timer. Thanks, drew #include <stdio.h> #define CONFIG_64BIT #include "kvm_util.h" #include "riscv/arch_timer.h" static unsigned long timer_freq; static unsigned int irq_fired; void mdelay(unsigned long msecs) { while (msecs--) udelay(1000); } static void guest_irq_handler(struct ex_regs *regs) { GUEST_PRINTF("%s\n", __func__); GUEST_ASSERT_EQ(regs->cause & ~CAUSE_IRQ_FLAG, IRQ_S_TIMER); irq_fired = 1; csr_write(CSR_STIMECMP, -1); while (csr_read(CSR_SIP) & IE_TIE) cpu_relax(); } static void guest_code(void) { GUEST_PRINTF("stage 1\n"); mdelay(1000); GUEST_ASSERT_EQ(irq_fired, 0); GUEST_PRINTF("stage 2\n"); timer_set_next_cval_ms(500); mdelay(1000); GUEST_ASSERT_EQ(irq_fired, 1); irq_fired = 0; GUEST_PRINTF("stage 3\n"); csr_clear(CSR_SIE, IE_TIE); timer_set_next_cval_ms(500); mdelay(1000); GUEST_ASSERT_EQ(irq_fired, 0); GUEST_PRINTF("stage 4\n"); csr_set(CSR_SIE, IE_TIE); mdelay(1); GUEST_ASSERT_EQ(irq_fired, 1); irq_fired = 0; GUEST_PRINTF("stage 5\n"); csr_clear(CSR_SSTATUS, SR_IE); timer_set_next_cval_ms(500); mdelay(1000); GUEST_ASSERT_EQ(irq_fired, 0); GUEST_PRINTF("stage 6\n"); csr_set(CSR_SSTATUS, SR_IE); mdelay(1); GUEST_ASSERT_EQ(irq_fired, 1); irq_fired = 0; GUEST_PRINTF("guest done\n"); GUEST_DONE(); } int main(void) { struct kvm_vcpu *vcpu; struct kvm_vm *vm; struct ucall uc; uint64_t val; int done = 0; vm = vm_create_with_one_vcpu(&vcpu, guest_code); vm_init_vector_tables(vm); vm_install_interrupt_handler(vm, guest_irq_handler); vcpu_init_vector_tables(vcpu); vcpu_set_reg(vcpu, RISCV_CSR_REG(sstatus), SR_IE); vcpu_set_reg(vcpu, RISCV_CSR_REG(sie), IE_TIE); vcpu_get_reg(vcpu, RISCV_TIMER_REG(frequency), &timer_freq); sync_global_to_guest(vm, timer_freq); vcpu_get_reg(vcpu, RISCV_TIMER_REG(compare), &val); assert(val == -1); while (!done) { vcpu_run(vcpu); switch (get_ucall(vcpu, &uc)) { case UCALL_PRINTF: printf("%s", uc.buffer); break; case UCALL_DONE: printf("Done.\n"); done = 1; break; } } }
On Fri, Sep 8, 2023 at 3:01 AM Andrew Jones <ajones@ventanamicro.com> wrote: > > On Thu, Sep 07, 2023 at 12:20:29PM +0800, Haibo Xu wrote: > > On Mon, Sep 4, 2023 at 10:58 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > > > > > 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@intel.com> > > > > --- > > > > > > 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. > > > > + * > > > > > guest_run[_stage]() can be shared with aarch64, we just have a single > > > stage=0 for riscv. > > > > > > > Yes, we can. But if we share the guest_run[_stage]() by moving it to > > kvm/arch_timer.c > > or kvm/include/timer_test.h, we need to declare extra sub-functions > > somewhere in a > > header file(etc. guest_configure_timer_action()). > > OK, whatever balances the reduction of duplicate code and avoidance of > exporting helper functions. BTW, riscv may not need/want all the same > helper functions as aarch64. Anyway, I guess I'll see how the next version > turns out. > > > > > > > + > > > > +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. > > > > > > > There is no local_irq_disable() protection during the initial debug > > phase, but the test always > > fail with below error messages: > > > > Guest assert failed, vcpu 0; stage; 0; iter: 0 > > ==== Test Assertion Failure ==== > > riscv/arch_timer.c:78: config_iter + 1 == irq_iter > > pid=585 tid=586 errno=4 - Interrupted system call > > (stack trace empty) > > 0x1 != 0x0 (config_iter + 1 != irq_iter) > > > > To be frank, I am not quite sure why the local_irq_disable/enable() matters. > > One possible reason may be some timer irq was triggered before we set up the > > timecmp register. > > We should ensure we know the exact, expected state of the vcpu before, > during, and after the test. If a state doesn't match expectations, > then the test should assert and we should go investigate the test code > to see if setup/checking is correct. If it is, then we've found a bug > in KVM that we need to go investigate. > > For Sstc, a pending timer interrupt completely depends on stimecmp, so > we need to watch that closely. Take a look at the attached simple timer > test I pulled together to illustrate how stimecmp, timer interrupt enable, > and all interrupt enable interact. You may want to use it to help port > the arch_timer. > Thanks for sharing the test codes. Will have an investigation on it. > Thanks, > drew
On Fri, Sep 8, 2023 at 9:19 AM Haibo Xu <xiaobo55x@gmail.com> wrote: > > On Fri, Sep 8, 2023 at 3:01 AM Andrew Jones <ajones@ventanamicro.com> wrote: > > > > On Thu, Sep 07, 2023 at 12:20:29PM +0800, Haibo Xu wrote: > > > On Mon, Sep 4, 2023 at 10:58 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > > > > > > > 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@intel.com> > > > > > --- > > > > > > > > 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. > > > > > > > > + > > > > > +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. > > > > > > > > > > There is no local_irq_disable() protection during the initial debug > > > phase, but the test always > > > fail with below error messages: > > > > > > Guest assert failed, vcpu 0; stage; 0; iter: 0 > > > ==== Test Assertion Failure ==== > > > riscv/arch_timer.c:78: config_iter + 1 == irq_iter > > > pid=585 tid=586 errno=4 - Interrupted system call > > > (stack trace empty) > > > 0x1 != 0x0 (config_iter + 1 != irq_iter) > > > > > > To be frank, I am not quite sure why the local_irq_disable/enable() matters. > > > One possible reason may be some timer irq was triggered before we set up the > > > timecmp register. > > > > We should ensure we know the exact, expected state of the vcpu before, > > during, and after the test. If a state doesn't match expectations, > > then the test should assert and we should go investigate the test code > > to see if setup/checking is correct. If it is, then we've found a bug > > in KVM that we need to go investigate. > > > > For Sstc, a pending timer interrupt completely depends on stimecmp, so > > we need to watch that closely. Take a look at the attached simple timer > > test I pulled together to illustrate how stimecmp, timer interrupt enable, > > and all interrupt enable interact. You may want to use it to help port > > the arch_timer. > > > > Thanks for sharing the test codes. Will have an investigation on it. > Hi Andrew, You are right. The local_irq_disable() was not needed here. It's my fault that I also removed the local_irq_enable() when trying your suggestion. Thanks for your review and help on this patch set! Regards, Haibo > > Thanks, > > drew
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 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 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); +} + +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) +{ + 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 /* 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 }; /* Shared variables between host and guest */ struct test_vcpu_shared_data { int nr_iter; +#ifdef __aarch64__ enum guest_stage guest_stage; +#endif 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; + + 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); + } +} + +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(); + + 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"); + + 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); +}
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@intel.com> --- 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