xref: /linux/tools/testing/selftests/kvm/pre_fault_memory_test.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2024, Intel, Inc
4  *
5  * Author:
6  * Isaku Yamahata <isaku.yamahata at gmail.com>
7  */
8 #include <linux/sizes.h>
9 
10 #include <test_util.h>
11 #include <kvm_util.h>
12 #include <processor.h>
13 
14 /* Arbitrarily chosen values */
15 #define TEST_SIZE		(SZ_2M + PAGE_SIZE)
16 #define TEST_NPAGES		(TEST_SIZE / PAGE_SIZE)
17 #define TEST_SLOT		10
18 
guest_code(uint64_t base_gpa)19 static void guest_code(uint64_t base_gpa)
20 {
21 	volatile uint64_t val __used;
22 	int i;
23 
24 	for (i = 0; i < TEST_NPAGES; i++) {
25 		uint64_t *src = (uint64_t *)(base_gpa + i * PAGE_SIZE);
26 
27 		val = *src;
28 	}
29 
30 	GUEST_DONE();
31 }
32 
pre_fault_memory(struct kvm_vcpu * vcpu,u64 gpa,u64 size,u64 left)33 static void pre_fault_memory(struct kvm_vcpu *vcpu, u64 gpa, u64 size,
34 			     u64 left)
35 {
36 	struct kvm_pre_fault_memory range = {
37 		.gpa = gpa,
38 		.size = size,
39 		.flags = 0,
40 	};
41 	u64 prev;
42 	int ret, save_errno;
43 
44 	do {
45 		prev = range.size;
46 		ret = __vcpu_ioctl(vcpu, KVM_PRE_FAULT_MEMORY, &range);
47 		save_errno = errno;
48 		TEST_ASSERT((range.size < prev) ^ (ret < 0),
49 			    "%sexpecting range.size to change on %s",
50 			    ret < 0 ? "not " : "",
51 			    ret < 0 ? "failure" : "success");
52 	} while (ret >= 0 ? range.size : save_errno == EINTR);
53 
54 	TEST_ASSERT(range.size == left,
55 		    "Completed with %lld bytes left, expected %" PRId64,
56 		    range.size, left);
57 
58 	if (left == 0)
59 		__TEST_ASSERT_VM_VCPU_IOCTL(!ret, "KVM_PRE_FAULT_MEMORY", ret, vcpu->vm);
60 	else
61 		/* No memory slot causes RET_PF_EMULATE. it results in -ENOENT. */
62 		__TEST_ASSERT_VM_VCPU_IOCTL(ret && save_errno == ENOENT,
63 					    "KVM_PRE_FAULT_MEMORY", ret, vcpu->vm);
64 }
65 
__test_pre_fault_memory(unsigned long vm_type,bool private)66 static void __test_pre_fault_memory(unsigned long vm_type, bool private)
67 {
68 	const struct vm_shape shape = {
69 		.mode = VM_MODE_DEFAULT,
70 		.type = vm_type,
71 	};
72 	struct kvm_vcpu *vcpu;
73 	struct kvm_run *run;
74 	struct kvm_vm *vm;
75 	struct ucall uc;
76 
77 	uint64_t guest_test_phys_mem;
78 	uint64_t guest_test_virt_mem;
79 	uint64_t alignment, guest_page_size;
80 
81 	vm = vm_create_shape_with_one_vcpu(shape, &vcpu, guest_code);
82 
83 	alignment = guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size;
84 	guest_test_phys_mem = (vm->max_gfn - TEST_NPAGES) * guest_page_size;
85 #ifdef __s390x__
86 	alignment = max(0x100000UL, guest_page_size);
87 #else
88 	alignment = SZ_2M;
89 #endif
90 	guest_test_phys_mem = align_down(guest_test_phys_mem, alignment);
91 	guest_test_virt_mem = guest_test_phys_mem & ((1ULL << (vm->va_bits - 1)) - 1);
92 
93 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
94 				    guest_test_phys_mem, TEST_SLOT, TEST_NPAGES,
95 				    private ? KVM_MEM_GUEST_MEMFD : 0);
96 	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, TEST_NPAGES);
97 
98 	if (private)
99 		vm_mem_set_private(vm, guest_test_phys_mem, TEST_SIZE);
100 	pre_fault_memory(vcpu, guest_test_phys_mem, SZ_2M, 0);
101 	pre_fault_memory(vcpu, guest_test_phys_mem + SZ_2M, PAGE_SIZE * 2, PAGE_SIZE);
102 	pre_fault_memory(vcpu, guest_test_phys_mem + TEST_SIZE, PAGE_SIZE, PAGE_SIZE);
103 
104 	vcpu_args_set(vcpu, 1, guest_test_virt_mem);
105 	vcpu_run(vcpu);
106 
107 	run = vcpu->run;
108 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
109 		    "Wanted KVM_EXIT_IO, got exit reason: %u (%s)",
110 		    run->exit_reason, exit_reason_str(run->exit_reason));
111 
112 	switch (get_ucall(vcpu, &uc)) {
113 	case UCALL_ABORT:
114 		REPORT_GUEST_ASSERT(uc);
115 		break;
116 	case UCALL_DONE:
117 		break;
118 	default:
119 		TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
120 		break;
121 	}
122 
123 	kvm_vm_free(vm);
124 }
125 
test_pre_fault_memory(unsigned long vm_type,bool private)126 static void test_pre_fault_memory(unsigned long vm_type, bool private)
127 {
128 	if (vm_type && !(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(vm_type))) {
129 		pr_info("Skipping tests for vm_type 0x%lx\n", vm_type);
130 		return;
131 	}
132 
133 	__test_pre_fault_memory(vm_type, private);
134 }
135 
main(int argc,char * argv[])136 int main(int argc, char *argv[])
137 {
138 	TEST_REQUIRE(kvm_check_cap(KVM_CAP_PRE_FAULT_MEMORY));
139 
140 	test_pre_fault_memory(0, false);
141 #ifdef __x86_64__
142 	test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, false);
143 	test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, true);
144 #endif
145 	return 0;
146 }
147