Split the vCPU descriptor table initialization process into a few steps and expose them: + Setting up the IDT + Syncing exception handlers into the guest In kvm_setup_idt(), we conditionally allocate guest memory for vm->idt to avoid double allocation when kvm_setup_idt() is used after vm_init_descriptor_tables(). Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx> --- .../selftests/kvm/include/x86_64/processor.h | 2 ++ .../selftests/kvm/lib/x86_64/processor.c | 19 ++++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 74e0d3698f30c..abaaab4d885c1 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -750,6 +750,8 @@ struct ex_regs { uint64_t rflags; }; +void kvm_setup_idt(struct kvm_vm *vm, struct kvm_dtable *dt); +void sync_exception_handlers_to_guest(struct kvm_vm *vm); void vm_init_descriptor_tables(struct kvm_vm *vm); void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu); void vm_install_exception_handler(struct kvm_vm *vm, int vector, diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 3046b555fee49..1ea1019d48c13 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1174,19 +1174,32 @@ void vm_init_descriptor_tables(struct kvm_vm *vm) DEFAULT_CODE_SELECTOR); } +void kvm_setup_idt(struct kvm_vm *vm, struct kvm_dtable *dt) +{ + if (!vm->idt) + vm->idt = vm_vaddr_alloc_page(vm); + + dt->base = vm->idt; + dt->limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1; +} + +void sync_exception_handlers_to_guest(struct kvm_vm *vm) +{ + *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; +} + void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu) { struct kvm_vm *vm = vcpu->vm; struct kvm_sregs sregs; vcpu_sregs_get(vcpu, &sregs); - sregs.idt.base = vm->idt; - sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1; + kvm_setup_idt(vcpu->vm, &sregs.idt); sregs.gdt.base = vm->gdt; sregs.gdt.limit = getpagesize() - 1; kvm_seg_set_kernel_data_64bit(NULL, DEFAULT_DATA_SELECTOR, &sregs.gs); vcpu_sregs_set(vcpu, &sregs); - *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; + sync_exception_handlers_to_guest(vm); } void vm_install_exception_handler(struct kvm_vm *vm, int vector, -- 2.39.0.246.g2a6d74b583-goog