On Tue, Feb 20, 2024 at 11:43 PM Binbin Wu binbin.wu@linux.intel.com wrote:
On 12/13/2023 4:46 AM, Sagi Shahar wrote:
From: Ackerley Tng ackerleytng@google.com
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@google.com Signed-off-by: Ryan Afranji afranji@google.com Signed-off-by: Sagi Shahar sagis@google.com
.../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 0b8855d68744..5c4e9a27d9e2 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -1089,6 +1089,8 @@ struct idt_entry { uint32_t offset2; uint32_t reserved; };
+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 b6b9438e0a33..566d82829da4 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1155,19 +1155,32 @@ 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);IDT is allocated in DATA memslot in current code, but here, when using vm_vaddr_alloc_page(), it will be allocated in TEST_DATA memslot.
Do we need to follow the current code to use __vm_vaddr_alloc_page(vm, MEM_REGION_DATA) instead?
This code is no longer needed after Sean's refactor in "[PATCH 00/18] KVM: selftests: Clean up x86's DT initialization" https://lore.kernel.org/lkml/20240314232637.2538648-1-seanjc@google.com/
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,