xref: /linux/tools/testing/selftests/kvm/x86/sev_dbg_test.c (revision b2128290c29902315e632ea59e0504d6bc9e9b42)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <fcntl.h>
3 #include <string.h>
4 #include <sys/ioctl.h>
5 
6 #include "test_util.h"
7 #include "kvm_util.h"
8 #include "processor.h"
9 #include "sev.h"
10 
11 #define BUFFER_SIZE	(PAGE_SIZE * 2)
12 
13 static u8 *data;
14 static u8 src[BUFFER_SIZE] __aligned(PAGE_SIZE);
15 static u8 dst[BUFFER_SIZE] __aligned(PAGE_SIZE);
16 
17 static void validate_dst(int i, int nr_bytes, u8 pattern)
18 {
19 	for ( ; i < nr_bytes; i++)
20 		TEST_ASSERT(dst[i] == pattern,
21 			    "Expected 0x%x at byte %u, got 0x%x",
22 			    pattern, i, dst[i]);
23 }
24 
25 static void validate_buffers(void)
26 {
27 	int i;
28 
29 	for (i = 0; i < BUFFER_SIZE; i++)
30 		TEST_ASSERT(src[i] == dst[i],
31 			    "Expected src[%u] (0x%x) == dst[%u] (0x%x)",
32 			    i, src[i], i, dst[i]);
33 }
34 
35 static void ____test_sev_dbg(struct kvm_vm *vm, int i, int j, int nr_bytes)
36 {
37 	u8 pattern = guest_random_u32(&guest_rng);
38 
39 	if (i + nr_bytes > BUFFER_SIZE || j + nr_bytes > BUFFER_SIZE)
40 		return;
41 
42 	memset(&src[i], pattern, nr_bytes);
43 	sev_encrypt_memory(vm, &data[j], &src[i], nr_bytes);
44 	sev_decrypt_memory(vm, &dst[i], &data[j], nr_bytes);
45 	validate_buffers();
46 	validate_dst(i, nr_bytes, pattern);
47 }
48 
49 static void __test_sev_dbg(struct kvm_vm *vm, int nr_bytes)
50 {
51 	/*
52 	 * In a perfect world, all sizes at all combinations within the buffers
53 	 * would be tested.  In reality, even this much testing is quite slow.
54 	 * Target sizes and offsets around the chunk (16 bytes) and page (4096
55 	 * bytes) sizes.
56 	 */
57 	int x[] = { 1, 8, 15, 16, 23 };
58 	int p = PAGE_SIZE - 24;
59 	int i, j;
60 
61 	____test_sev_dbg(vm, 0, 0, nr_bytes);
62 
63 	for (i = 0; i < ARRAY_SIZE(x); i++) {
64 		for (j = 0; j < ARRAY_SIZE(x); j++) {
65 			____test_sev_dbg(vm, x[i], x[j], nr_bytes);
66 			____test_sev_dbg(vm, x[i], p + x[j], nr_bytes);
67 			____test_sev_dbg(vm, p + x[i], x[j], nr_bytes);
68 			____test_sev_dbg(vm, p + x[i], p + x[j], nr_bytes);
69 		}
70 	}
71 }
72 
73 static void test_sev_dbg(u32 type, u64 policy)
74 {
75 	int sizes[] = { 1, 8, 15, 16, 17, 32, 33 };
76 	struct kvm_vcpu *vcpu;
77 	struct kvm_vm *vm;
78 	int i;
79 
80 	if (!(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(type)))
81 		return;
82 
83 	vm = vm_sev_create_with_one_vcpu(type, NULL, &vcpu);
84 
85 	data = addr_gva2hva(vm, vm_alloc(vm, BUFFER_SIZE, KVM_UTIL_MIN_VADDR));
86 	memset(data, 0xaa, BUFFER_SIZE);
87 
88 	vm_sev_launch(vm, policy, NULL);
89 
90 	sev_decrypt_memory(vm, dst, data, BUFFER_SIZE);
91 	validate_dst(0, BUFFER_SIZE, 0xaa);
92 
93 	memset(src, 0x55, BUFFER_SIZE);
94 	sev_encrypt_memory(vm, data, src, BUFFER_SIZE);
95 	sev_decrypt_memory(vm, dst, data, BUFFER_SIZE);
96 	validate_dst(0, BUFFER_SIZE, 0x55);
97 
98 	__test_sev_dbg(vm, PAGE_SIZE);
99 
100 	for (i = 0; i < ARRAY_SIZE(sizes); i++) {
101 		__test_sev_dbg(vm, sizes[i]);
102 		__test_sev_dbg(vm, PAGE_SIZE - sizes[i]);
103 		__test_sev_dbg(vm, PAGE_SIZE + sizes[i]);
104 		__test_sev_dbg(vm, BUFFER_SIZE - sizes[i]);
105 	}
106 
107 	kvm_vm_free(vm);
108 }
109 
110 int main(int argc, char *argv[])
111 {
112 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV));
113 
114 	/* Note, KVM doesn't support {de,en}crypt commands for SNP. */
115 	test_sev_dbg(KVM_X86_SEV_VM, 0);
116 	test_sev_dbg(KVM_X86_SEV_ES_VM, SEV_POLICY_ES);
117 	return 0;
118 }
119