Add the infrastructure for guest exception handling in riscv selftests. Customized handlers can be enabled by vm_install_exception_handler(vector) or vm_install_interrupt_handler().
The code is inspired from that of x86/arm64.
Signed-off-by: Haibo Xu haibo1.xu@intel.com Reviewed-by: Andrew Jones ajones@ventanamicro.com --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/riscv/processor.h | 43 ++++++++ .../selftests/kvm/lib/riscv/handlers.S | 101 ++++++++++++++++++ .../selftests/kvm/lib/riscv/processor.c | 69 ++++++++++++ 4 files changed, 214 insertions(+) create mode 100644 tools/testing/selftests/kvm/lib/riscv/handlers.S
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 89ecee2fdb73..a5bc8e156047 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -53,6 +53,7 @@ LIBKVM_s390x += lib/s390x/diag318_test_handler.c LIBKVM_s390x += lib/s390x/processor.c LIBKVM_s390x += lib/s390x/ucall.c
+LIBKVM_riscv += lib/riscv/handlers.S LIBKVM_riscv += lib/riscv/processor.c LIBKVM_riscv += lib/riscv/ucall.c
diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h index 67766baed4f7..2c975d9cead2 100644 --- a/tools/testing/selftests/kvm/include/riscv/processor.h +++ b/tools/testing/selftests/kvm/include/riscv/processor.h @@ -42,6 +42,49 @@ static inline uint64_t __kvm_reg_id(uint64_t type, uint64_t idx, #define RISCV_ISA_EXT_REG(idx) __kvm_reg_id(KVM_REG_RISCV_ISA_EXT, \ idx, KVM_REG_SIZE_ULONG)
+struct ex_regs { + unsigned long ra; + unsigned long sp; + unsigned long gp; + unsigned long tp; + unsigned long t0; + unsigned long t1; + unsigned long t2; + unsigned long s0; + unsigned long s1; + unsigned long a0; + unsigned long a1; + unsigned long a2; + unsigned long a3; + unsigned long a4; + unsigned long a5; + unsigned long a6; + unsigned long a7; + unsigned long s2; + unsigned long s3; + unsigned long s4; + unsigned long s5; + unsigned long s6; + unsigned long s7; + unsigned long s8; + unsigned long s9; + unsigned long s10; + unsigned long s11; + unsigned long t3; + unsigned long t4; + unsigned long t5; + unsigned long t6; + unsigned long epc; + unsigned long status; + unsigned long cause; +}; + +#define NR_VECTORS 2 +#define NR_EXCEPTIONS 32 +#define EC_MASK (NR_EXCEPTIONS - 1) + +void vm_install_interrupt_handler(struct kvm_vm *vm, exception_handler_fn handler); + /* L3 index Bit[47:39] */ #define PGTBL_L3_INDEX_MASK 0x0000FF8000000000ULL #define PGTBL_L3_INDEX_SHIFT 39 diff --git a/tools/testing/selftests/kvm/lib/riscv/handlers.S b/tools/testing/selftests/kvm/lib/riscv/handlers.S new file mode 100644 index 000000000000..aa0abd3f35bb --- /dev/null +++ b/tools/testing/selftests/kvm/lib/riscv/handlers.S @@ -0,0 +1,101 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2023 Intel Corporation + */ + +#ifndef __ASSEMBLY__ +#define __ASSEMBLY__ +#endif + +#include <asm/csr.h> + +.macro save_context + addi sp, sp, (-8*34) + sd x1, 0(sp) + sd x2, 8(sp) + sd x3, 16(sp) + sd x4, 24(sp) + sd x5, 32(sp) + sd x6, 40(sp) + sd x7, 48(sp) + sd x8, 56(sp) + sd x9, 64(sp) + sd x10, 72(sp) + sd x11, 80(sp) + sd x12, 88(sp) + sd x13, 96(sp) + sd x14, 104(sp) + sd x15, 112(sp) + sd x16, 120(sp) + sd x17, 128(sp) + sd x18, 136(sp) + sd x19, 144(sp) + sd x20, 152(sp) + sd x21, 160(sp) + sd x22, 168(sp) + sd x23, 176(sp) + sd x24, 184(sp) + sd x25, 192(sp) + sd x26, 200(sp) + sd x27, 208(sp) + sd x28, 216(sp) + sd x29, 224(sp) + sd x30, 232(sp) + sd x31, 240(sp) + csrr s0, CSR_SEPC + csrr s1, CSR_SSTATUS + csrr s2, CSR_SCAUSE + sd s0, 248(sp) + sd s1, 256(sp) + sd s2, 264(sp) +.endm + +.macro restore_context + ld s2, 264(sp) + ld s1, 256(sp) + ld s0, 248(sp) + csrw CSR_SCAUSE, s2 + csrw CSR_SSTATUS, s1 + csrw CSR_SEPC, s0 + ld x31, 240(sp) + ld x30, 232(sp) + ld x29, 224(sp) + ld x28, 216(sp) + ld x27, 208(sp) + ld x26, 200(sp) + ld x25, 192(sp) + ld x24, 184(sp) + ld x23, 176(sp) + ld x22, 168(sp) + ld x21, 160(sp) + ld x20, 152(sp) + ld x19, 144(sp) + ld x18, 136(sp) + ld x17, 128(sp) + ld x16, 120(sp) + ld x15, 112(sp) + ld x14, 104(sp) + ld x13, 96(sp) + ld x12, 88(sp) + ld x11, 80(sp) + ld x10, 72(sp) + ld x9, 64(sp) + ld x8, 56(sp) + ld x7, 48(sp) + ld x6, 40(sp) + ld x5, 32(sp) + ld x4, 24(sp) + ld x3, 16(sp) + ld x2, 8(sp) + ld x1, 0(sp) + addi sp, sp, (8*34) +.endm + +.balign 4 +.global exception_vectors +exception_vectors: + save_context + move a0, sp + call route_exception + restore_context + sret diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c index d146ca71e0c0..efd9ac4b0198 100644 --- a/tools/testing/selftests/kvm/lib/riscv/processor.c +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c @@ -13,6 +13,8 @@
#define DEFAULT_RISCV_GUEST_STACK_VADDR_MIN 0xac0000
+static vm_vaddr_t exception_handlers; + static uint64_t page_align(struct kvm_vm *vm, uint64_t v) { return (v + vm->page_size) & ~(vm->page_size - 1); @@ -364,6 +366,73 @@ void vcpu_args_set(struct kvm_vcpu *vcpu, unsigned int num, ...) va_end(ap); }
+void kvm_exit_unexpected_exception(int vector, int ec) +{ + ucall(UCALL_UNHANDLED, 2, vector, ec); +} + void assert_on_unhandled_exception(struct kvm_vcpu *vcpu) { + struct ucall uc; + + if (get_ucall(vcpu, &uc) == UCALL_UNHANDLED) { + TEST_FAIL("Unexpected exception (vector:0x%lx, ec:0x%lx)", + uc.args[0], uc.args[1]); + } +} + +struct handlers { + exception_handler_fn exception_handlers[NR_VECTORS][NR_EXCEPTIONS]; +}; + +void route_exception(struct ex_regs *regs) +{ + struct handlers *handlers = (struct handlers *)exception_handlers; + int vector = 0, ec; + + ec = regs->cause & ~CAUSE_IRQ_FLAG; + if (ec >= NR_EXCEPTIONS) + goto unexpected_exception; + + /* Use the same handler for all the interrupts */ + if (regs->cause & CAUSE_IRQ_FLAG) { + vector = 1; + ec = 0; + } + + if (handlers && handlers->exception_handlers[vector][ec]) + return handlers->exception_handlers[vector][ec](regs); + +unexpected_exception: + return kvm_exit_unexpected_exception(vector, ec); +} + +void vcpu_init_vector_tables(struct kvm_vcpu *vcpu) +{ + extern char exception_vectors; + + vcpu_set_reg(vcpu, RISCV_CSR_REG(stvec), (unsigned long)&exception_vectors); +} + +void vm_init_vector_tables(struct kvm_vm *vm) +{ + vm->handlers = __vm_vaddr_alloc(vm, sizeof(struct handlers), + vm->page_size, MEM_REGION_DATA); + + *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; +} + +void vm_install_exception_handler(struct kvm_vm *vm, int vector, exception_handler_fn handler) +{ + struct handlers *handlers = addr_gva2hva(vm, vm->handlers); + + assert(vector < NR_EXCEPTIONS); + handlers->exception_handlers[0][vector] = handler; +} + +void vm_install_interrupt_handler(struct kvm_vm *vm, exception_handler_fn handler) +{ + struct handlers *handlers = addr_gva2hva(vm, vm->handlers); + + handlers->exception_handlers[1][0] = handler; }