KVM: selftests: Move raw KVM_SET_USER_MEMORY_REGION helper to utils

Move set_memory_region_test's KVM_SET_USER_MEMORY_REGION helper to KVM's
utils so that it can be used by other tests.  Provide a raw version as
well as an assert-success version to reduce the amount of boilerplate
code need for basic usage.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220226001546.360188-26-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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

@@ -147,6 +147,10 @@ void vcpu_dump(FILE *stream, struct kvm_vm *vm, uint32_t vcpuid,
 
 void vm_create_irqchip(struct kvm_vm *vm);
 
+void vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags,
+			       uint64_t gpa, uint64_t size, void *hva);
+int __vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags,
+				uint64_t gpa, uint64_t size, void *hva);
 void vm_userspace_mem_region_add(struct kvm_vm *vm,
 	enum vm_mem_backing_src_type src_type,
 	uint64_t guest_paddr, uint32_t slot, uint64_t npages,

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

@@ -839,6 +839,30 @@ static void vm_userspace_mem_region_hva_insert(struct rb_root *hva_tree,
 	rb_insert_color(&region->hva_node, hva_tree);
 }
 
+
+int __vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags,
+				uint64_t gpa, uint64_t size, void *hva)
+{
+	struct kvm_userspace_memory_region region = {
+		.slot = slot,
+		.flags = flags,
+		.guest_phys_addr = gpa,
+		.memory_size = size,
+		.userspace_addr = (uintptr_t)hva,
+	};
+
+	return ioctl(vm->fd, KVM_SET_USER_MEMORY_REGION, &region);
+}
+
+void vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags,
+			       uint64_t gpa, uint64_t size, void *hva)
+{
+	int ret = __vm_set_user_memory_region(vm, slot, flags, gpa, size, hva);
+
+	TEST_ASSERT(!ret, "KVM_SET_USER_MEMORY_REGION failed, errno = %d (%s)",
+		    errno, strerror(errno));
+}
+
 /*
  * VM Userspace Memory Region Add
  *

tools/testing/selftests/kvm/set_memory_region_test.c

@@ -329,22 +329,6 @@ static void test_zero_memory_regions(void)
 }
 #endif /* __x86_64__ */
 
-static int test_memory_region_add(struct kvm_vm *vm, void *mem, uint32_t slot,
-				   uint32_t size, uint64_t guest_addr)
-{
-	struct kvm_userspace_memory_region region;
-	int ret;
-
-	region.slot = slot;
-	region.flags = 0;
-	region.guest_phys_addr = guest_addr;
-	region.memory_size = size;
-	region.userspace_addr = (uintptr_t) mem;
-	ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION, &region);
-
-	return ret;
-}
-
 /*
  * Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS, then any
  * tentative to add further slots should fail.
@@ -382,23 +366,20 @@ static void test_add_max_memory_regions(void)
 	TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");
 	mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1));
 
-	for (slot = 0; slot < max_mem_slots; slot++) {
-		ret = test_memory_region_add(vm, mem_aligned +
-					     ((uint64_t)slot * MEM_REGION_SIZE),
-					     slot, MEM_REGION_SIZE,
-					     (uint64_t)slot * MEM_REGION_SIZE);
-		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"
-			    "  rc: %i errno: %i slot: %i\n",
-			    ret, errno, slot);
-	}
+	for (slot = 0; slot < max_mem_slots; slot++)
+		vm_set_user_memory_region(vm, slot, 0,
+					  ((uint64_t)slot * MEM_REGION_SIZE),
+					  MEM_REGION_SIZE,
+					  mem_aligned + (uint64_t)slot * MEM_REGION_SIZE);
 
 	/* Check it cannot be added memory slots beyond the limit */
 	mem_extra = mmap(NULL, MEM_REGION_SIZE, PROT_READ | PROT_WRITE,
 			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	TEST_ASSERT(mem_extra != MAP_FAILED, "Failed to mmap() host");
 
-	ret = test_memory_region_add(vm, mem_extra, max_mem_slots, MEM_REGION_SIZE,
-				     (uint64_t)max_mem_slots * MEM_REGION_SIZE);
+	ret = __vm_set_user_memory_region(vm, max_mem_slots, 0,
+					  (uint64_t)max_mem_slots * MEM_REGION_SIZE,
+					  MEM_REGION_SIZE, mem_extra);
 	TEST_ASSERT(ret == -1 && errno == EINVAL,
 		    "Adding one more memory slot should fail with EINVAL");