Add interrupt and exception handler register interface. When exception happens, execute registered exception handler if exists, else report error.

Signed-off-by: Bibo Mao maobibo@loongson.cn --- .../kvm/include/loongarch/processor.h | 14 +++++++++ .../selftests/kvm/lib/loongarch/processor.c | 29 +++++++++++++++++++ 2 files changed, 43 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/loongarch/processor.h b/tools/testing/selftests/kvm/include/loongarch/processor.h index 374caddfb0db..a18ac7bff303 100644 --- a/tools/testing/selftests/kvm/include/loongarch/processor.h +++ b/tools/testing/selftests/kvm/include/loongarch/processor.h @@ -84,6 +84,11 @@ #define LOONGARCH_CSR_EUEN 0x2 #define LOONGARCH_CSR_ECFG 0x4 #define LOONGARCH_CSR_ESTAT 0x5 /* Exception status */ +#define CSR_ESTAT_EXC_SHIFT 16 +#define CSR_ESTAT_EXC_WIDTH 6 +#define CSR_ESTAT_EXC (0x3f << CSR_ESTAT_EXC_SHIFT) +#define EXCCODE_INT 0 /* Interrupt */ +#define INT_TI 11 /* Timer interrupt*/ #define LOONGARCH_CSR_ERA 0x6 /* ERA */ #define LOONGARCH_CSR_BADV 0x7 /* Bad virtual address */ #define LOONGARCH_CSR_EENTRY 0xc @@ -133,6 +138,15 @@ struct ex_regs { #define PRMD_OFFSET_EXREGS offsetof(struct ex_regs, prmd) #define EXREGS_SIZE sizeof(struct ex_regs)

+#define VECTOR_NUM 64 +typedef void(*handler_fn)(struct ex_regs *); +struct handlers { + handler_fn exception_handlers[VECTOR_NUM]; +}; + +void vm_init_descriptor_tables(struct kvm_vm *vm); +void vm_install_exception_handler(struct kvm_vm *vm, int vector, handler_fn handler); + #else #define PC_OFFSET_EXREGS ((EXREGS_GPRS + 0) * 8) #define ESTAT_OFFSET_EXREGS ((EXREGS_GPRS + 1) * 8) diff --git a/tools/testing/selftests/kvm/lib/loongarch/processor.c b/tools/testing/selftests/kvm/lib/loongarch/processor.c index 0ac1abcb71cb..be537c5ff74e 100644 --- a/tools/testing/selftests/kvm/lib/loongarch/processor.c +++ b/tools/testing/selftests/kvm/lib/loongarch/processor.c @@ -11,6 +11,7 @@ #define LOONGARCH_GUEST_STACK_VADDR_MIN 0x200000

static vm_paddr_t invalid_pgtable[4]; +static vm_vaddr_t exception_handlers;

static uint64_t virt_pte_index(struct kvm_vm *vm, vm_vaddr_t gva, int level) { @@ -184,6 +185,13 @@ void assert_on_unhandled_exception(struct kvm_vcpu *vcpu) void route_exception(struct ex_regs *regs) { unsigned long pc, estat, badv; + int vector; + struct handlers *handlers; + + handlers = (struct handlers *)exception_handlers; + vector = (regs->estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT; + if (handlers && handlers->exception_handlers[vector]) + return handlers->exception_handlers[vector](regs);

pc = regs->pc; badv = regs->badv; @@ -192,6 +200,27 @@ void route_exception(struct ex_regs *regs) while (1) ; }

+void vm_init_descriptor_tables(struct kvm_vm *vm) +{ + void *addr; + + vm->handlers = __vm_vaddr_alloc(vm, sizeof(struct handlers), + LOONGARCH_GUEST_STACK_VADDR_MIN, MEM_REGION_DATA); + + addr = addr_gva2hva(vm, vm->handlers); + memset(addr, 0, vm->page_size); + exception_handlers = vm->handlers; + sync_global_to_guest(vm, exception_handlers); +} + +void vm_install_exception_handler(struct kvm_vm *vm, int vector, handler_fn handler) +{ + struct handlers *handlers = addr_gva2hva(vm, vm->handlers); + + assert(vector < VECTOR_NUM); + handlers->exception_handlers[vector] = handler; +} + void vcpu_args_set(struct kvm_vcpu *vcpu, unsigned int num, ...) { int i;

Add timer test case based on common arch_timer code, one-shot mode is tested with timer interrupt.

Signed-off-by: Bibo Mao maobibo@loongson.cn --- tools/testing/selftests/kvm/Makefile.kvm | 10 +- .../kvm/include/loongarch/arch_timer.h | 79 +++++++++++++++ .../kvm/include/loongarch/processor.h | 10 ++ .../selftests/kvm/lib/loongarch/processor.c | 4 +- .../selftests/kvm/loongarch/arch_timer.c | 98 +++++++++++++++++++ 5 files changed, 196 insertions(+), 5 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/loongarch/arch_timer.h create mode 100644 tools/testing/selftests/kvm/loongarch/arch_timer.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 148d427ff24b..662adf8f309b 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -183,6 +183,8 @@ TEST_GEN_PROGS_arm64 += memslot_perf_test TEST_GEN_PROGS_arm64 += mmu_stress_test TEST_GEN_PROGS_arm64 += rseq_test TEST_GEN_PROGS_arm64 += steal_time +SPLIT_TESTS_arm64 += arch_timer +SPLIT_TESTS_arm64 += get-reg-list

TEST_GEN_PROGS_s390 = $(TEST_GEN_PROGS_COMMON) TEST_GEN_PROGS_s390 += s390/memop @@ -209,6 +211,8 @@ TEST_GEN_PROGS_riscv += memslot_perf_test TEST_GEN_PROGS_riscv += mmu_stress_test TEST_GEN_PROGS_riscv += rseq_test TEST_GEN_PROGS_riscv += steal_time +SPLIT_TESTS_riscv += arch_timer +SPLIT_TESTS_riscv += get-reg-list

TEST_GEN_PROGS_loongarch += coalesced_io_test TEST_GEN_PROGS_loongarch += demand_paging_test @@ -222,10 +226,10 @@ TEST_GEN_PROGS_loongarch += kvm_page_table_test TEST_GEN_PROGS_loongarch += memslot_modification_stress_test TEST_GEN_PROGS_loongarch += memslot_perf_test TEST_GEN_PROGS_loongarch += set_memory_region_test +TEST_GEN_PROGS_loongarch += arch_timer +SPLIT_TESTS_loongarch = arch_timer

-SPLIT_TESTS += arch_timer -SPLIT_TESTS += get-reg-list - +SPLIT_TESTS += $(SPLIT_TESTS_$(ARCH)) TEST_PROGS += $(TEST_PROGS_$(ARCH)) TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(ARCH)) TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(ARCH)) diff --git a/tools/testing/selftests/kvm/include/loongarch/arch_timer.h b/tools/testing/selftests/kvm/include/loongarch/arch_timer.h new file mode 100644 index 000000000000..94b1cba2744d --- /dev/null +++ b/tools/testing/selftests/kvm/include/loongarch/arch_timer.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * LoongArch Constant Timer specific interface + */ +#ifndef SELFTEST_KVM_ARCH_TIMER_H +#define SELFTEST_KVM_ARCH_TIMER_H + +#include "processor.h" +/* LoongArch timer frequency is constant 100MHZ */ +#define TIMER_FREQ (100UL << 20) +#define msec_to_cycles(msec) (TIMER_FREQ * (unsigned long)(msec) / 1000) +#define usec_to_cycles(usec) (TIMER_FREQ * (unsigned long)(usec) / 1000000) +#define cycles_to_usec(cycles) ((unsigned long)(cycles) * 1000000 / TIMER_FREQ) + +static inline unsigned long timer_get_cycles(void) +{ + unsigned long val = 0; + + __asm__ __volatile__( + "rdtime.d %0, $zero\n\t" + : "=r"(val) + : + ); + + return val; +} + +static inline void timer_set_next_cmp_ms(unsigned int msec, bool period) +{ + unsigned long val; + + val = msec_to_cycles(msec) & CSR_TCFG_VAL; + val |= CSR_TCFG_EN; + if (period) + val |= CSR_TCFG_PERIOD; + csr_write(val, LOONGARCH_CSR_TCFG); +} + +static inline unsigned long timer_get_val(void) +{ + return csr_read(LOONGARCH_CSR_TVAL); +} + +static inline unsigned long timer_get_cfg(void) +{ + return csr_read(LOONGARCH_CSR_TCFG); +} + +static inline void timer_irq_enable(void) +{ + unsigned long val; + + val = csr_read(LOONGARCH_CSR_ECFG); + val |= ECFGF_TIMER; + csr_write(val, LOONGARCH_CSR_ECFG); +} + +static inline void timer_irq_disable(void) +{ + unsigned long val; + + val = csr_read(LOONGARCH_CSR_ECFG); + val &= ~ECFGF_TIMER; + csr_write(val, LOONGARCH_CSR_ECFG); +} + +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/loongarch/processor.h b/tools/testing/selftests/kvm/include/loongarch/processor.h index b027f8f4dac7..61f6e215046b 100644 --- a/tools/testing/selftests/kvm/include/loongarch/processor.h +++ b/tools/testing/selftests/kvm/include/loongarch/processor.h @@ -83,6 +83,8 @@ #define LOONGARCH_CSR_PRMD 0x1 #define LOONGARCH_CSR_EUEN 0x2 #define LOONGARCH_CSR_ECFG 0x4 +#define ECFGB_TIMER 11 +#define ECFGF_TIMER (BIT_ULL(ECFGB_TIMER)) #define LOONGARCH_CSR_ESTAT 0x5 /* Exception status */ #define CSR_ESTAT_EXC_SHIFT 16 #define CSR_ESTAT_EXC_WIDTH 6 @@ -111,6 +113,14 @@ #define LOONGARCH_CSR_KS1 0x31 #define LOONGARCH_CSR_TMID 0x40 #define LOONGARCH_CSR_TCFG 0x41 +#define CSR_TCFG_VAL (BIT_ULL(48) - BIT_ULL(2)) +#define CSR_TCFG_PERIOD_SHIFT 1 +#define CSR_TCFG_PERIOD (0x1UL << CSR_TCFG_PERIOD_SHIFT) +#define CSR_TCFG_EN (0x1UL) +#define LOONGARCH_CSR_TVAL 0x42 +#define LOONGARCH_CSR_TINTCLR 0x44 /* Timer interrupt clear */ +#define CSR_TINTCLR_TI_SHIFT 0 +#define CSR_TINTCLR_TI (1 << CSR_TINTCLR_TI_SHIFT) /* TLB refill exception entry */ #define LOONGARCH_CSR_TLBRENTRY 0x88 #define LOONGARCH_CSR_TLBRSAVE 0x8b diff --git a/tools/testing/selftests/kvm/lib/loongarch/processor.c b/tools/testing/selftests/kvm/lib/loongarch/processor.c index 20ba476ccb72..436990258068 100644 --- a/tools/testing/selftests/kvm/lib/loongarch/processor.c +++ b/tools/testing/selftests/kvm/lib/loongarch/processor.c @@ -271,8 +271,8 @@ static void loongarch_vcpu_setup(struct kvm_vcpu *vcpu) TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode); }

- /* user mode and page enable mode */ - val = PLV_USER | CSR_CRMD_PG; + /* kernel mode and page enable mode */ + val = PLV_KERN | CSR_CRMD_PG; loongarch_set_csr(vcpu, LOONGARCH_CSR_CRMD, val); loongarch_set_csr(vcpu, LOONGARCH_CSR_PRMD, val); loongarch_set_csr(vcpu, LOONGARCH_CSR_EUEN, 1); diff --git a/tools/testing/selftests/kvm/loongarch/arch_timer.c b/tools/testing/selftests/kvm/loongarch/arch_timer.c new file mode 100644 index 000000000000..2a2cebcf3885 --- /dev/null +++ b/tools/testing/selftests/kvm/loongarch/arch_timer.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * The test validates one-shot constant timer IRQ using CSR_TCFG and + * CSR_TVAL registers. + */ +#include "arch_timer.h" +#include "kvm_util.h" +#include "processor.h" +#include "timer_test.h" +#include "ucall_common.h" + +static void guest_irq_handler(struct ex_regs *regs) +{ + uint64_t xcnt, val, cfg, xcnt_diff_us; + unsigned int intid; + uint32_t cpu = guest_get_vcpuid(); + struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu]; + + intid = !!(regs->estat & BIT(INT_TI)); + + /* Make sure we are dealing with the correct timer IRQ */ + GUEST_ASSERT_EQ(intid, 1); + + cfg = timer_get_cfg(); + + /* + * On physical machine, value of LOONGARCH_CSR_TVAL is BIT_ULL(48) - 1 + * On virtual machine, its value counts down from BIT_ULL(48) - 1 + */ + val = timer_get_val(); + xcnt = timer_get_cycles(); + xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt); + + /* Basic 'timer condition met' check */ + __GUEST_ASSERT(val > cfg, + "val = 0x%lx, cfg = 0x%lx, xcnt_diff_us = 0x%lx", + val, cfg, xcnt_diff_us); + + csr_write(CSR_TINTCLR_TI, LOONGARCH_CSR_TINTCLR); + WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1); +} + +static void guest_test_oneshot_timer(uint32_t cpu) +{ + uint32_t irq_iter, config_iter; + uint64_t us; + struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu]; + + shared_data->nr_iter = 0; + shared_data->guest_stage = 0; + us = msecs_to_usecs(test_args.timer_period_ms) + test_args.timer_err_margin_us; + for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) { + shared_data->xcnt = timer_get_cycles(); + + /* Setup the next interrupt */ + timer_set_next_cmp_ms(test_args.timer_period_ms, false); + /* Setup a timeout for the interrupt to arrive */ + udelay(us); + + irq_iter = READ_ONCE(shared_data->nr_iter); + __GUEST_ASSERT(config_iter + 1 == irq_iter, + "config_iter + 1 = 0x%x, irq_iter = 0x%x.\n" + " Guest timer interrupt was not triggered within the specified\n" + " interval, try to increase the error margin by [-e] option.\n", + config_iter + 1, irq_iter); + } +} + +static void guest_code(void) +{ + uint32_t cpu = guest_get_vcpuid(); + + timer_irq_enable(); + local_irq_enable(); + guest_test_oneshot_timer(cpu); + + 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); + vm_init_descriptor_tables(vm); + vm_install_exception_handler(vm, EXCCODE_INT, guest_irq_handler); + + /* 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); +}

This test case setup one-shot timer and execute idle instruction immediately to indicate giving up CPU, hypervisor will emulate SW hrtimer and wakeup vCPU when SW hrtimer is fired.

Signed-off-by: Bibo Mao maobibo@loongson.cn --- .../selftests/kvm/loongarch/arch_timer.c | 40 +++++++++++++++++++ 1 file changed, 40 insertions(+)

diff --git a/tools/testing/selftests/kvm/loongarch/arch_timer.c b/tools/testing/selftests/kvm/loongarch/arch_timer.c index 1be42ef33bf3..a30dd0414a34 100644 --- a/tools/testing/selftests/kvm/loongarch/arch_timer.c +++ b/tools/testing/selftests/kvm/loongarch/arch_timer.c @@ -114,6 +114,45 @@ static void guest_time_count_test(uint32_t cpu) } }

+static void do_idle(void) +{ + unsigned int intid; + unsigned long estat; + + __asm__ __volatile__("idle 0" : : : "memory"); + + estat = csr_read(LOONGARCH_CSR_ESTAT); + intid = !!(estat & BIT(INT_TI)); + + /* Make sure pending timer IRQ arrived */ + GUEST_ASSERT_EQ(intid, 1); + csr_write(CSR_TINTCLR_TI, LOONGARCH_CSR_TINTCLR); +} + +static void guest_test_emulate_timer(uint32_t cpu) +{ + uint32_t config_iter; + uint64_t xcnt_diff_us, us; + struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu]; + + local_irq_disable(); + shared_data->nr_iter = 0; + us = msecs_to_usecs(test_args.timer_period_ms); + for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) { + shared_data->xcnt = timer_get_cycles(); + + /* Setup the next interrupt */ + timer_set_next_cmp_ms(test_args.timer_period_ms, false); + do_idle(); + + xcnt_diff_us = cycles_to_usec(timer_get_cycles() - shared_data->xcnt); + __GUEST_ASSERT(xcnt_diff_us >= us, + "xcnt_diff_us = 0x%lx, us = 0x%lx.\n", + xcnt_diff_us, us); + } + local_irq_enable(); +} + static void guest_code(void) { uint32_t cpu = guest_get_vcpuid(); @@ -123,6 +162,7 @@ static void guest_code(void) local_irq_enable(); guest_test_oneshot_timer(cpu); guest_test_period_timer(cpu); + guest_test_emulate_timer(cpu);

GUEST_DONE(); }