KVM: selftests: Introduce VM "shape" to allow tests to specify the VM type

Add a "vm_shape" structure to encapsulate the selftests-defined "mode",
along with the KVM-defined "type" for use when creating a new VM.  "mode"
tracks physical and virtual address properties, as well as the preferred
backing memory type, while "type" corresponds to the VM type.

Taking the VM type will allow adding tests for KVM_CREATE_GUEST_MEMFD
without needing an entirely separate set of helpers.  At this time,
guest_memfd is effectively usable only by confidential VM types in the
form of guest private memory, and it's expected that x86 will double down
and require unique VM types for TDX and SNP guests.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-30-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 22 insertions, 21 deletions

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index cc6007abc4b1..bf15635eda11 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -209,7 +209,7 @@ __weak void vm_vaddr_populate_bitmap(struct kvm_vm *vm)
 		(1ULL << (vm->va_bits - 1)) >> vm->page_shift);
 }
 
-struct kvm_vm *____vm_create(enum vm_guest_mode mode)
+struct kvm_vm *____vm_create(struct vm_shape shape)
 {
 	struct kvm_vm *vm;
 
@@ -221,13 +221,13 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
 	vm->regions.hva_tree = RB_ROOT;
 	hash_init(vm->regions.slot_hash);
 
-	vm->mode = mode;
-	vm->type = 0;
+	vm->mode = shape.mode;
+	vm->type = shape.type;
 
-	vm->pa_bits = vm_guest_mode_params[mode].pa_bits;
-	vm->va_bits = vm_guest_mode_params[mode].va_bits;
-	vm->page_size = vm_guest_mode_params[mode].page_size;
-	vm->page_shift = vm_guest_mode_params[mode].page_shift;
+	vm->pa_bits = vm_guest_mode_params[vm->mode].pa_bits;
+	vm->va_bits = vm_guest_mode_params[vm->mode].va_bits;
+	vm->page_size = vm_guest_mode_params[vm->mode].page_size;
+	vm->page_shift = vm_guest_mode_params[vm->mode].page_shift;
 
 	/* Setup mode specific traits. */
 	switch (vm->mode) {
@@ -265,7 +265,7 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
 		/*
 		 * Ignore KVM support for 5-level paging (vm->va_bits == 57),
 		 * it doesn't take effect unless a CR4.LA57 is set, which it
-		 * isn't for this VM_MODE.
+		 * isn't for this mode (48-bit virtual address space).
 		 */
 		TEST_ASSERT(vm->va_bits == 48 || vm->va_bits == 57,
 			    "Linear address width (%d bits) not supported",
@@ -285,10 +285,11 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
 		vm->pgtable_levels = 5;
 		break;
 	default:
-		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
+		TEST_FAIL("Unknown guest mode: 0x%x", vm->mode);
 	}
 
 #ifdef __aarch64__
+	TEST_ASSERT(!vm->type, "ARM doesn't support test-provided types");
 	if (vm->pa_bits != 40)
 		vm->type = KVM_VM_TYPE_ARM_IPA_SIZE(vm->pa_bits);
 #endif
@@ -347,19 +348,19 @@ static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
 	return vm_adjust_num_guest_pages(mode, nr_pages);
 }
 
-struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus,
+struct kvm_vm *__vm_create(struct vm_shape shape, uint32_t nr_runnable_vcpus,
 			   uint64_t nr_extra_pages)
 {
-	uint64_t nr_pages = vm_nr_pages_required(mode, nr_runnable_vcpus,
+	uint64_t nr_pages = vm_nr_pages_required(shape.mode, nr_runnable_vcpus,
 						 nr_extra_pages);
 	struct userspace_mem_region *slot0;
 	struct kvm_vm *vm;
 	int i;
 
-	pr_debug("%s: mode='%s' pages='%ld'\n", __func__,
-		 vm_guest_mode_string(mode), nr_pages);
+	pr_debug("%s: mode='%s' type='%d', pages='%ld'\n", __func__,
+		 vm_guest_mode_string(shape.mode), shape.type, nr_pages);
 
-	vm = ____vm_create(mode);
+	vm = ____vm_create(shape);
 
 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, 0);
 	for (i = 0; i < NR_MEM_REGIONS; i++)
@@ -400,7 +401,7 @@ struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus,
  * extra_mem_pages is only used to calculate the maximum page table size,
  * no real memory allocation for non-slot0 memory in this function.
  */
-struct kvm_vm *__vm_create_with_vcpus(enum vm_guest_mode mode, uint32_t nr_vcpus,
+struct kvm_vm *__vm_create_with_vcpus(struct vm_shape shape, uint32_t nr_vcpus,
 				      uint64_t extra_mem_pages,
 				      void *guest_code, struct kvm_vcpu *vcpus[])
 {
@@ -409,7 +410,7 @@ struct kvm_vm *__vm_create_with_vcpus(enum vm_guest_mode mode, uint32_t nr_vcpus
 
 	TEST_ASSERT(!nr_vcpus || vcpus, "Must provide vCPU array");
 
-	vm = __vm_create(mode, nr_vcpus, extra_mem_pages);
+	vm = __vm_create(shape, nr_vcpus, extra_mem_pages);
 
 	for (i = 0; i < nr_vcpus; ++i)
 		vcpus[i] = vm_vcpu_add(vm, i, guest_code);
@@ -417,15 +418,15 @@ struct kvm_vm *__vm_create_with_vcpus(enum vm_guest_mode mode, uint32_t nr_vcpus
 	return vm;
 }
 
-struct kvm_vm *__vm_create_with_one_vcpu(struct kvm_vcpu **vcpu,
-					 uint64_t extra_mem_pages,
-					 void *guest_code)
+struct kvm_vm *__vm_create_shape_with_one_vcpu(struct vm_shape shape,
+					       struct kvm_vcpu **vcpu,
+					       uint64_t extra_mem_pages,
+					       void *guest_code)
 {
 	struct kvm_vcpu *vcpus[1];
 	struct kvm_vm *vm;
 
-	vm = __vm_create_with_vcpus(VM_MODE_DEFAULT, 1, extra_mem_pages,
-				    guest_code, vcpus);
+	vm = __vm_create_with_vcpus(shape, 1, extra_mem_pages, guest_code, vcpus);
 
 	*vcpu = vcpus[0];
 	return vm;