KVM: selftests: Add util to delete memory region

Add a utility to delete a memory region, it will be used by x86's
set_memory_region_test.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20200410231707.7128-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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

@@ -114,6 +114,7 @@ int _vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, unsigned long ioctl,
 void vm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
 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);
 void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
 			  uint32_t data_memslot, uint32_t pgd_memslot);

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

@@ -433,34 +433,38 @@ void kvm_vm_release(struct kvm_vm *vmp)
 		"  vmp->kvm_fd: %i rc: %i errno: %i", vmp->kvm_fd, ret, errno);
 }
 
+static void __vm_mem_region_delete(struct kvm_vm *vm,
+				   struct userspace_mem_region *region)
+{
+	int ret;
+
+	list_del(&region->list);
+
+	region->region.memory_size = 0;
+	ret = ioctl(vm->fd, KVM_SET_USER_MEMORY_REGION, &region->region);
+	TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed, "
+		    "rc: %i errno: %i", ret, errno);
+
+	sparsebit_free(&region->unused_phy_pages);
+	ret = munmap(region->mmap_start, region->mmap_size);
+	TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
+
+	free(region);
+}
+
 /*
  * Destroys and frees the VM pointed to by vmp.
  */
 void kvm_vm_free(struct kvm_vm *vmp)
 {
 	struct userspace_mem_region *region, *tmp;
-	int ret;
 
 	if (vmp == NULL)
 		return;
 
 	/* Free userspace_mem_regions. */
-	list_for_each_entry_safe(region, tmp, &vmp->userspace_mem_regions, list) {
-		list_del(&region->list);
-
-		region->region.memory_size = 0;
-		ret = ioctl(vmp->fd, KVM_SET_USER_MEMORY_REGION,
-			&region->region);
-		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed, "
-			"rc: %i errno: %i", ret, errno);
-
-		sparsebit_free(&region->unused_phy_pages);
-		ret = munmap(region->mmap_start, region->mmap_size);
-		TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i",
-			    ret, errno);
-
-		free(region);
-	}
+	list_for_each_entry_safe(region, tmp, &vmp->userspace_mem_regions, list)
+		__vm_mem_region_delete(vmp, region);
 
 	/* Free sparsebit arrays. */
 	sparsebit_free(&vmp->vpages_valid);
@@ -775,6 +779,24 @@ void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa)
 		    ret, errno, slot, new_gpa);
 }
 
+/*
+ * VM Memory Region Delete
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   slot - Slot of the memory region to delete
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Delete a memory region.
+ */
+void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot)
+{
+	__vm_mem_region_delete(vm, memslot2region(vm, slot));
+}
+
 /*
  * VCPU mmap Size
  *