Add the infrastructure needed to enable exception handling in aarch64 selftests. The exception handling defaults to an unhandled-exception handler which aborts the test, just like x86. These handlers can be overridden by calling vm_handle_exception with a (vector, error-code) tuple. The unhandled exception reporting from the guest is done using the new ucall UCALL_UNHANDLED.
Signed-off-by: Ricardo Koller <[email protected]> --- tools/testing/selftests/kvm/Makefile | 2 +- .../selftests/kvm/include/aarch64/processor.h | 69 ++++++++++++ .../testing/selftests/kvm/include/kvm_util.h | 1 + .../selftests/kvm/lib/aarch64/handlers.S | 104 ++++++++++++++++++ .../selftests/kvm/lib/aarch64/processor.c | 56 ++++++++++ 5 files changed, 231 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/lib/aarch64/handlers.S diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 4e548d7ab0ab..618c5903f478 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -35,7 +35,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S -LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c +LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h index b7fa0c8551db..5c902ad95c35 100644 --- a/tools/testing/selftests/kvm/include/aarch64/processor.h +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h @@ -8,6 +8,7 @@ #define SELFTEST_KVM_PROCESSOR_H #include "kvm_util.h" +#include <linux/stringify.h> #define ARM64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \ @@ -18,6 +19,7 @@ #define MAIR_EL1 3, 0, 10, 2, 0 #define TTBR0_EL1 3, 0, 2, 0, 0 #define SCTLR_EL1 3, 0, 1, 0, 0 +#define VBAR_EL1 3, 0, 12, 0, 0 /* * Default MAIR @@ -56,4 +58,71 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, int vcpuid, struct kvm_vcpu_init *ini void aarch64_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_vcpu_init *init, void *guest_code); +struct ex_regs { + u64 pc; + u64 pstate; + u64 sp; + u64 lr; + u64 regs[31]; +}; + +#define VECTOR_NUM 16 + +enum { + VECTOR_SYNC_EL1_SP0, + VECTOR_IRQ_EL1_SP0, + VECTOR_FIQ_EL1_SP0, + VECTOR_ERROR_EL1_SP0, + + VECTOR_SYNC_EL1, + VECTOR_IRQ_EL1, + VECTOR_FIQ_EL1, + VECTOR_ERROR_EL1, + + VECTOR_SYNC_EL0_64, + VECTOR_IRQ_EL0_64, + VECTOR_FIQ_EL0_64, + VECTOR_ERROR_EL0_64, + + VECTOR_SYNC_EL0_32, + VECTOR_IRQ_EL0_32, + VECTOR_FIQ_EL0_32, + VECTOR_ERROR_EL0_32, +}; + +/* Some common EC (Exception classes) */ +#define ESR_EC_ILLEGAL_INS 0x0e +#define ESR_EC_SVC64 0x15 +#define ESR_EC_IABORT_EL1 0x21 +#define ESR_EC_DABORT_EL1 0x25 +#define ESR_EC_SERROR 0x2f +#define ESR_EC_HW_BP_EL1 0x31 +#define ESR_EC_SSTEP_EL1 0x33 +#define ESR_EC_WP_EL1 0x35 +#define ESR_EC_BRK_INS 0x3C + +#define ESR_EC_NUM 64 + +#define ESR_EC_SHIFT 26 +#define ESR_EC_MASK 0x3f + +void vm_init_descriptor_tables(struct kvm_vm *vm); +void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid); +void vm_handle_exception(struct kvm_vm *vm, int vector, int ec, + void (*handler)(struct ex_regs *)); + +#define SPSR_D (1 << 9) +#define SPSR_SS (1 << 21) + +#define write_sysreg(reg, val) \ +({ \ + asm volatile("msr "__stringify(reg)", %0" : : "r"(val)); \ +}) + +#define read_sysreg(reg) \ +({ u64 val; \ + asm volatile("mrs %0, "__stringify(reg) : "=r"(val) : : "memory");\ + val; \ +}) + #endif /* SELFTEST_KVM_PROCESSOR_H */ diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index bea4644d645d..7880929ea548 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -347,6 +347,7 @@ enum { UCALL_SYNC, UCALL_ABORT, UCALL_DONE, + UCALL_UNHANDLED, }; #define UCALL_MAX_ARGS 6 diff --git a/tools/testing/selftests/kvm/lib/aarch64/handlers.S b/tools/testing/selftests/kvm/lib/aarch64/handlers.S new file mode 100644 index 000000000000..c920679b87c0 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/aarch64/handlers.S @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +.macro save_registers, el + stp x28, x29, [sp, #-16]! + stp x26, x27, [sp, #-16]! + stp x24, x25, [sp, #-16]! + stp x22, x23, [sp, #-16]! + stp x20, x21, [sp, #-16]! + stp x18, x19, [sp, #-16]! + stp x16, x17, [sp, #-16]! + stp x14, x15, [sp, #-16]! + stp x12, x13, [sp, #-16]! + stp x10, x11, [sp, #-16]! + stp x8, x9, [sp, #-16]! + stp x6, x7, [sp, #-16]! + stp x4, x5, [sp, #-16]! + stp x2, x3, [sp, #-16]! + stp x0, x1, [sp, #-16]! + + .if \el == 0 + mrs x1, sp_el0 + .else + mov x1, sp + .endif + stp x1, lr, [sp, #-16]! /* SP, LR */ + + mrs x1, elr_el1 + mrs x2, spsr_el1 + stp x1, x2, [sp, #-16]! /* PC, PSTATE */ +.endm + +.macro restore_registers, el + ldp x1, x2, [sp], #16 /* PC, PSTATE */ + msr elr_el1, x1 + msr spsr_el1, x2 + + ldp x1, lr, [sp], #16 /* SP, LR */ + .if \el == 0 + msr sp_el0, x1 + .endif + + ldp x0, x1, [sp], #16 + ldp x2, x3, [sp], #16 + ldp x4, x5, [sp], #16 + ldp x6, x7, [sp], #16 + ldp x8, x9, [sp], #16 + ldp x10, x11, [sp], #16 + ldp x12, x13, [sp], #16 + ldp x14, x15, [sp], #16 + ldp x16, x17, [sp], #16 + ldp x18, x19, [sp], #16 + ldp x20, x21, [sp], #16 + ldp x22, x23, [sp], #16 + ldp x24, x25, [sp], #16 + ldp x26, x27, [sp], #16 + ldp x28, x29, [sp], #16 + + eret +.endm + +.pushsection ".entry.text", "ax" +.balign 0x800 +.global vectors +vectors: +.popsection + +/* + * Build an exception handler for vector and append a jump to it into + * vectors (while making sure that it's 0x80 aligned). + */ +.macro HANDLER, el, label, vector +handler\()\vector: + save_registers \el + mov x0, sp + mov x1, \vector + bl route_exception + restore_registers \el + +.pushsection ".entry.text", "ax" +.balign 0x80 + b handler\()\vector +.popsection +.endm + +.global ex_handler_code +ex_handler_code: + HANDLER 1, sync, 0 // Synchronous EL1t + HANDLER 1, irq, 1 // IRQ EL1t + HANDLER 1, fiq, 2 // FIQ EL1t + HANDLER 1, error, 3 // Error EL1t + + HANDLER 1, sync, 4 // Synchronous EL1h + HANDLER 1, irq, 5 // IRQ EL1h + HANDLER 1, fiq, 6 // FIQ EL1h + HANDLER 1, error, 7 // Error EL1h + + HANDLER 0, sync, 8 // Synchronous 64-bit EL0 + HANDLER 0, irq, 9 // IRQ 64-bit EL0 + HANDLER 0, fiq, 10 // FIQ 64-bit EL0 + HANDLER 0, error, 11 // Error 64-bit EL0 + + HANDLER 0, sync, 12 // Synchronous 32-bit EL0 + HANDLER 0, irq, 13 // IRQ 32-bit EL0 + HANDLER 0, fiq, 14 // FIQ 32-bit EL0 + HANDLER 0, error, 15 // Error 32-bit EL0 diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c index cee92d477dc0..286305b561d8 100644 --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c @@ -6,6 +6,7 @@ */ #include <linux/compiler.h> +#include <assert.h> #include "kvm_util.h" #include "../kvm_util_internal.h" @@ -14,6 +15,8 @@ #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000 #define DEFAULT_ARM64_GUEST_STACK_VADDR_MIN 0xac0000 +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); @@ -336,4 +339,57 @@ void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...) void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid) { + struct ucall uc; + + if (get_ucall(vm, vcpuid, &uc) == UCALL_UNHANDLED) { + TEST_ASSERT(false, + "Unexpected exception guest (vector:0x%lx, ec:0x%lx)", + uc.args[0], uc.args[1]); + } +} + +void kvm_exit_unexpected_vector(int vector, uint64_t ec) +{ + ucall(UCALL_UNHANDLED, 2, vector, ec); +} + +#define HANDLERS_IDX(_vector, _ec) ((_vector * ESR_EC_NUM) + _ec) + +void vm_init_descriptor_tables(struct kvm_vm *vm) +{ + vm->handlers = vm_vaddr_alloc(vm, + VECTOR_NUM * ESR_EC_NUM * sizeof(void *), + vm->page_size, 0, 0); + *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; +} + +void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid) +{ + extern char vectors; + + set_reg(vm, vcpuid, ARM64_SYS_REG(VBAR_EL1), (uint64_t)&vectors); +} + +void route_exception(struct ex_regs *regs, int vector) +{ + typedef void(*handler)(struct ex_regs *); + uint64_t esr = read_sysreg(esr_el1); + uint64_t ec = (esr >> ESR_EC_SHIFT) & ESR_EC_MASK; + + handler *handlers = (handler *)exception_handlers; + + if (handlers && handlers[HANDLERS_IDX(vector, ec)]) + handlers[HANDLERS_IDX(vector, ec)](regs); + else + kvm_exit_unexpected_vector(vector, ec); +} + +void vm_handle_exception(struct kvm_vm *vm, int vector, int ec, + void (*handler)(struct ex_regs *)) +{ + vm_vaddr_t *handlers = (vm_vaddr_t *)addr_gva2hva(vm, vm->handlers); + + assert(vector < VECTOR_NUM); + assert(ec < ESR_EC_NUM); + handlers[HANDLERS_IDX(vector, ec)] = (vm_vaddr_t)handler; } -- 2.31.1.498.g6c1eba8ee3d-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
