KVM: selftests: Export vm_vaddr_unused_gap() to make it possible to request unmapped ranges

Currently, tests can only request a new vaddr range by using
vm_vaddr_alloc()/vm_vaddr_alloc_page()/vm_vaddr_alloc_pages() but
these functions allocate and map physical pages too. Make it possible
to request unmapped range too.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-36-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/include/kvm_util_base.h

@@ -385,6 +385,7 @@ void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
 void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
 void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
 struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id);
+vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
 vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
 vm_vaddr_t vm_vaddr_alloc_page(struct kvm_vm *vm);

tools/testing/selftests/kvm/lib/kvm_util.c

@@ -1214,8 +1214,8 @@ struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
  * TEST_ASSERT failure occurs for invalid input or no area of at least
  * sz unallocated bytes >= vaddr_min is available.
  */
-static vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz,
-				      vm_vaddr_t vaddr_min)
+vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz,
+			       vm_vaddr_t vaddr_min)
 {
 	uint64_t pages = (sz + vm->page_size - 1) >> vm->page_shift;