On 12/13/2023 4:46 AM, Sagi Shahar wrote:
From: Ackerley Tng <ackerleytng@xxxxxxxxxx>
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>
Signed-off-by: Ryan Afranji <afranji@xxxxxxxxxx>
Signed-off-by: Sagi Shahar <sagis@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 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?
+
+ 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,
