summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/kvm/aarch64/hypercalls.c
blob: 31f66ba97228babe46bf2c46640077065ded7241 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
// SPDX-License-Identifier: GPL-2.0-only

/* hypercalls: Check the ARM64's psuedo-firmware bitmap register interface.
 *
 * The test validates the basic hypercall functionalities that are exposed
 * via the psuedo-firmware bitmap register. This includes the registers'
 * read/write behavior before and after the VM has started, and if the
 * hypercalls are properly masked or unmasked to the guest when disabled or
 * enabled from the KVM userspace, respectively.
 */
#include <errno.h>
#include <linux/arm-smccc.h>
#include <asm/kvm.h>
#include <kvm_util.h>

#include "processor.h"

#define FW_REG_ULIMIT_VAL(max_feat_bit) (GENMASK(max_feat_bit, 0))

/* Last valid bits of the bitmapped firmware registers */
#define KVM_REG_ARM_STD_BMAP_BIT_MAX		0
#define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX	0
#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX	1

struct kvm_fw_reg_info {
	uint64_t reg;		/* Register definition */
	uint64_t max_feat_bit;	/* Bit that represents the upper limit of the feature-map */
};

#define FW_REG_INFO(r)			\
	{					\
		.reg = r,			\
		.max_feat_bit = r##_BIT_MAX,	\
	}

static const struct kvm_fw_reg_info fw_reg_info[] = {
	FW_REG_INFO(KVM_REG_ARM_STD_BMAP),
	FW_REG_INFO(KVM_REG_ARM_STD_HYP_BMAP),
	FW_REG_INFO(KVM_REG_ARM_VENDOR_HYP_BMAP),
};

enum test_stage {
	TEST_STAGE_REG_IFACE,
	TEST_STAGE_HVC_IFACE_FEAT_DISABLED,
	TEST_STAGE_HVC_IFACE_FEAT_ENABLED,
	TEST_STAGE_HVC_IFACE_FALSE_INFO,
	TEST_STAGE_END,
};

static int stage = TEST_STAGE_REG_IFACE;

struct test_hvc_info {
	uint32_t func_id;
	uint64_t arg1;
};

#define TEST_HVC_INFO(f, a1)	\
	{			\
		.func_id = f,	\
		.arg1 = a1,	\
	}

static const struct test_hvc_info hvc_info[] = {
	/* KVM_REG_ARM_STD_BMAP */
	TEST_HVC_INFO(ARM_SMCCC_TRNG_VERSION, 0),
	TEST_HVC_INFO(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_TRNG_RND64),
	TEST_HVC_INFO(ARM_SMCCC_TRNG_GET_UUID, 0),
	TEST_HVC_INFO(ARM_SMCCC_TRNG_RND32, 0),
	TEST_HVC_INFO(ARM_SMCCC_TRNG_RND64, 0),

	/* KVM_REG_ARM_STD_HYP_BMAP */
	TEST_HVC_INFO(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_HV_PV_TIME_FEATURES),
	TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_FEATURES, ARM_SMCCC_HV_PV_TIME_ST),
	TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_ST, 0),

	/* KVM_REG_ARM_VENDOR_HYP_BMAP */
	TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID,
			ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID),
	TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, 0),
	TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, KVM_PTP_VIRT_COUNTER),
};

/* Feed false hypercall info to test the KVM behavior */
static const struct test_hvc_info false_hvc_info[] = {
	/* Feature support check against a different family of hypercalls */
	TEST_HVC_INFO(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID),
	TEST_HVC_INFO(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_TRNG_RND64),
	TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_FEATURES, ARM_SMCCC_TRNG_RND64),
};

static void guest_test_hvc(const struct test_hvc_info *hc_info)
{
	unsigned int i;
	struct arm_smccc_res res;
	unsigned int hvc_info_arr_sz;

	hvc_info_arr_sz =
	hc_info == hvc_info ? ARRAY_SIZE(hvc_info) : ARRAY_SIZE(false_hvc_info);

	for (i = 0; i < hvc_info_arr_sz; i++, hc_info++) {
		memset(&res, 0, sizeof(res));
		smccc_hvc(hc_info->func_id, hc_info->arg1, 0, 0, 0, 0, 0, 0, &res);

		switch (stage) {
		case TEST_STAGE_HVC_IFACE_FEAT_DISABLED:
		case TEST_STAGE_HVC_IFACE_FALSE_INFO:
			__GUEST_ASSERT(res.a0 == SMCCC_RET_NOT_SUPPORTED,
				       "a0 = 0x%lx, func_id = 0x%x, arg1 = 0x%llx, stage = %u",
					res.a0, hc_info->func_id, hc_info->arg1, stage);
			break;
		case TEST_STAGE_HVC_IFACE_FEAT_ENABLED:
			__GUEST_ASSERT(res.a0 != SMCCC_RET_NOT_SUPPORTED,
				       "a0 = 0x%lx, func_id = 0x%x, arg1 = 0x%llx, stage = %u",
					res.a0, hc_info->func_id, hc_info->arg1, stage);
			break;
		default:
			GUEST_FAIL("Unexpected stage = %u", stage);
		}
	}
}

static void guest_code(void)
{
	while (stage != TEST_STAGE_END) {
		switch (stage) {
		case TEST_STAGE_REG_IFACE:
			break;
		case TEST_STAGE_HVC_IFACE_FEAT_DISABLED:
		case TEST_STAGE_HVC_IFACE_FEAT_ENABLED:
			guest_test_hvc(hvc_info);
			break;
		case TEST_STAGE_HVC_IFACE_FALSE_INFO:
			guest_test_hvc(false_hvc_info);
			break;
		default:
			GUEST_FAIL("Unexpected stage = %u", stage);
		}

		GUEST_SYNC(stage);
	}

	GUEST_DONE();
}

struct st_time {
	uint32_t rev;
	uint32_t attr;
	uint64_t st_time;
};

#define STEAL_TIME_SIZE		((sizeof(struct st_time) + 63) & ~63)
#define ST_GPA_BASE		(1 << 30)

static void steal_time_init(struct kvm_vcpu *vcpu)
{
	uint64_t st_ipa = (ulong)ST_GPA_BASE;
	unsigned int gpages;

	gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE);
	vm_userspace_mem_region_add(vcpu->vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);

	vcpu_device_attr_set(vcpu, KVM_ARM_VCPU_PVTIME_CTRL,
			     KVM_ARM_VCPU_PVTIME_IPA, &st_ipa);
}

static void test_fw_regs_before_vm_start(struct kvm_vcpu *vcpu)
{
	uint64_t val;
	unsigned int i;
	int ret;

	for (i = 0; i < ARRAY_SIZE(fw_reg_info); i++) {
		const struct kvm_fw_reg_info *reg_info = &fw_reg_info[i];

		/* First 'read' should be an upper limit of the features supported */
		vcpu_get_reg(vcpu, reg_info->reg, &val);
		TEST_ASSERT(val == FW_REG_ULIMIT_VAL(reg_info->max_feat_bit),
			"Expected all the features to be set for reg: 0x%lx; expected: 0x%lx; read: 0x%lx\n",
			reg_info->reg, FW_REG_ULIMIT_VAL(reg_info->max_feat_bit), val);

		/* Test a 'write' by disabling all the features of the register map */
		ret = __vcpu_set_reg(vcpu, reg_info->reg, 0);
		TEST_ASSERT(ret == 0,
			"Failed to clear all the features of reg: 0x%lx; ret: %d\n",
			reg_info->reg, errno);

		vcpu_get_reg(vcpu, reg_info->reg, &val);
		TEST_ASSERT(val == 0,
			"Expected all the features to be cleared for reg: 0x%lx\n", reg_info->reg);

		/*
		 * Test enabling a feature that's not supported.
		 * Avoid this check if all the bits are occupied.
		 */
		if (reg_info->max_feat_bit < 63) {
			ret = __vcpu_set_reg(vcpu, reg_info->reg, BIT(reg_info->max_feat_bit + 1));
			TEST_ASSERT(ret != 0 && errno == EINVAL,
			"Unexpected behavior or return value (%d) while setting an unsupported feature for reg: 0x%lx\n",
			errno, reg_info->reg);
		}
	}
}

static void test_fw_regs_after_vm_start(struct kvm_vcpu *vcpu)
{
	uint64_t val;
	unsigned int i;
	int ret;

	for (i = 0; i < ARRAY_SIZE(fw_reg_info); i++) {
		const struct kvm_fw_reg_info *reg_info = &fw_reg_info[i];

		/*
		 * Before starting the VM, the test clears all the bits.
		 * Check if that's still the case.
		 */
		vcpu_get_reg(vcpu, reg_info->reg, &val);
		TEST_ASSERT(val == 0,
			"Expected all the features to be cleared for reg: 0x%lx\n",
			reg_info->reg);

		/*
		 * Since the VM has run at least once, KVM shouldn't allow modification of
		 * the registers and should return EBUSY. Set the registers and check for
		 * the expected errno.
		 */
		ret = __vcpu_set_reg(vcpu, reg_info->reg, FW_REG_ULIMIT_VAL(reg_info->max_feat_bit));
		TEST_ASSERT(ret != 0 && errno == EBUSY,
		"Unexpected behavior or return value (%d) while setting a feature while VM is running for reg: 0x%lx\n",
		errno, reg_info->reg);
	}
}

static struct kvm_vm *test_vm_create(struct kvm_vcpu **vcpu)
{
	struct kvm_vm *vm;

	vm = vm_create_with_one_vcpu(vcpu, guest_code);

	steal_time_init(*vcpu);

	return vm;
}

static void test_guest_stage(struct kvm_vm **vm, struct kvm_vcpu **vcpu)
{
	int prev_stage = stage;

	pr_debug("Stage: %d\n", prev_stage);

	/* Sync the stage early, the VM might be freed below. */
	stage++;
	sync_global_to_guest(*vm, stage);

	switch (prev_stage) {
	case TEST_STAGE_REG_IFACE:
		test_fw_regs_after_vm_start(*vcpu);
		break;
	case TEST_STAGE_HVC_IFACE_FEAT_DISABLED:
		/* Start a new VM so that all the features are now enabled by default */
		kvm_vm_free(*vm);
		*vm = test_vm_create(vcpu);
		break;
	case TEST_STAGE_HVC_IFACE_FEAT_ENABLED:
	case TEST_STAGE_HVC_IFACE_FALSE_INFO:
		break;
	default:
		TEST_FAIL("Unknown test stage: %d\n", prev_stage);
	}
}

static void test_run(void)
{
	struct kvm_vcpu *vcpu;
	struct kvm_vm *vm;
	struct ucall uc;
	bool guest_done = false;

	vm = test_vm_create(&vcpu);

	test_fw_regs_before_vm_start(vcpu);

	while (!guest_done) {
		vcpu_run(vcpu);

		switch (get_ucall(vcpu, &uc)) {
		case UCALL_SYNC:
			test_guest_stage(&vm, &vcpu);
			break;
		case UCALL_DONE:
			guest_done = true;
			break;
		case UCALL_ABORT:
			REPORT_GUEST_ASSERT(uc);
			break;
		default:
			TEST_FAIL("Unexpected guest exit\n");
		}
	}

	kvm_vm_free(vm);
}

int main(void)
{
	test_run();
	return 0;
}