xref: /openbmc/linux/arch/arm64/kvm/guest.c (revision 930beb5a)
1 /*
2  * Copyright (C) 2012,2013 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * Derived from arch/arm/kvm/guest.c:
6  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include <linux/errno.h>
23 #include <linux/err.h>
24 #include <linux/kvm_host.h>
25 #include <linux/module.h>
26 #include <linux/vmalloc.h>
27 #include <linux/fs.h>
28 #include <asm/cputype.h>
29 #include <asm/uaccess.h>
30 #include <asm/kvm.h>
31 #include <asm/kvm_asm.h>
32 #include <asm/kvm_emulate.h>
33 #include <asm/kvm_coproc.h>
34 
35 struct kvm_stats_debugfs_item debugfs_entries[] = {
36 	{ NULL }
37 };
38 
39 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
40 {
41 	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
42 	return 0;
43 }
44 
45 static u64 core_reg_offset_from_id(u64 id)
46 {
47 	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
48 }
49 
50 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
51 {
52 	/*
53 	 * Because the kvm_regs structure is a mix of 32, 64 and
54 	 * 128bit fields, we index it as if it was a 32bit
55 	 * array. Hence below, nr_regs is the number of entries, and
56 	 * off the index in the "array".
57 	 */
58 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
59 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
60 	int nr_regs = sizeof(*regs) / sizeof(__u32);
61 	u32 off;
62 
63 	/* Our ID is an index into the kvm_regs struct. */
64 	off = core_reg_offset_from_id(reg->id);
65 	if (off >= nr_regs ||
66 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
67 		return -ENOENT;
68 
69 	if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
70 		return -EFAULT;
71 
72 	return 0;
73 }
74 
75 static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
76 {
77 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
78 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
79 	int nr_regs = sizeof(*regs) / sizeof(__u32);
80 	__uint128_t tmp;
81 	void *valp = &tmp;
82 	u64 off;
83 	int err = 0;
84 
85 	/* Our ID is an index into the kvm_regs struct. */
86 	off = core_reg_offset_from_id(reg->id);
87 	if (off >= nr_regs ||
88 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
89 		return -ENOENT;
90 
91 	if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
92 		return -EINVAL;
93 
94 	if (copy_from_user(valp, uaddr, KVM_REG_SIZE(reg->id))) {
95 		err = -EFAULT;
96 		goto out;
97 	}
98 
99 	if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
100 		u32 mode = (*(u32 *)valp) & COMPAT_PSR_MODE_MASK;
101 		switch (mode) {
102 		case COMPAT_PSR_MODE_USR:
103 		case COMPAT_PSR_MODE_FIQ:
104 		case COMPAT_PSR_MODE_IRQ:
105 		case COMPAT_PSR_MODE_SVC:
106 		case COMPAT_PSR_MODE_ABT:
107 		case COMPAT_PSR_MODE_UND:
108 		case PSR_MODE_EL0t:
109 		case PSR_MODE_EL1t:
110 		case PSR_MODE_EL1h:
111 			break;
112 		default:
113 			err = -EINVAL;
114 			goto out;
115 		}
116 	}
117 
118 	memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));
119 out:
120 	return err;
121 }
122 
123 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
124 {
125 	return -EINVAL;
126 }
127 
128 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
129 {
130 	return -EINVAL;
131 }
132 
133 static unsigned long num_core_regs(void)
134 {
135 	return sizeof(struct kvm_regs) / sizeof(__u32);
136 }
137 
138 /**
139  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
140  *
141  * This is for all registers.
142  */
143 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
144 {
145 	return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu);
146 }
147 
148 /**
149  * kvm_arm_copy_reg_indices - get indices of all registers.
150  *
151  * We do core registers right here, then we apppend system regs.
152  */
153 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
154 {
155 	unsigned int i;
156 	const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
157 
158 	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
159 		if (put_user(core_reg | i, uindices))
160 			return -EFAULT;
161 		uindices++;
162 	}
163 
164 	return kvm_arm_copy_sys_reg_indices(vcpu, uindices);
165 }
166 
167 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
168 {
169 	/* We currently use nothing arch-specific in upper 32 bits */
170 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
171 		return -EINVAL;
172 
173 	/* Register group 16 means we want a core register. */
174 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
175 		return get_core_reg(vcpu, reg);
176 
177 	return kvm_arm_sys_reg_get_reg(vcpu, reg);
178 }
179 
180 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
181 {
182 	/* We currently use nothing arch-specific in upper 32 bits */
183 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
184 		return -EINVAL;
185 
186 	/* Register group 16 means we set a core register. */
187 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
188 		return set_core_reg(vcpu, reg);
189 
190 	return kvm_arm_sys_reg_set_reg(vcpu, reg);
191 }
192 
193 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
194 				  struct kvm_sregs *sregs)
195 {
196 	return -EINVAL;
197 }
198 
199 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
200 				  struct kvm_sregs *sregs)
201 {
202 	return -EINVAL;
203 }
204 
205 int __attribute_const__ kvm_target_cpu(void)
206 {
207 	unsigned long implementor = read_cpuid_implementor();
208 	unsigned long part_number = read_cpuid_part_number();
209 
210 	if (implementor != ARM_CPU_IMP_ARM)
211 		return -EINVAL;
212 
213 	switch (part_number) {
214 	case ARM_CPU_PART_AEM_V8:
215 		return KVM_ARM_TARGET_AEM_V8;
216 	case ARM_CPU_PART_FOUNDATION:
217 		return KVM_ARM_TARGET_FOUNDATION_V8;
218 	case ARM_CPU_PART_CORTEX_A57:
219 		/* Currently handled by the generic backend */
220 		return KVM_ARM_TARGET_CORTEX_A57;
221 	default:
222 		return -EINVAL;
223 	}
224 }
225 
226 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
227 			const struct kvm_vcpu_init *init)
228 {
229 	unsigned int i;
230 	int phys_target = kvm_target_cpu();
231 
232 	if (init->target != phys_target)
233 		return -EINVAL;
234 
235 	vcpu->arch.target = phys_target;
236 	bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
237 
238 	/* -ENOENT for unknown features, -EINVAL for invalid combinations. */
239 	for (i = 0; i < sizeof(init->features) * 8; i++) {
240 		if (init->features[i / 32] & (1 << (i % 32))) {
241 			if (i >= KVM_VCPU_MAX_FEATURES)
242 				return -ENOENT;
243 			set_bit(i, vcpu->arch.features);
244 		}
245 	}
246 
247 	/* Now we know what it is, we can reset it. */
248 	return kvm_reset_vcpu(vcpu);
249 }
250 
251 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
252 {
253 	int target = kvm_target_cpu();
254 
255 	if (target < 0)
256 		return -ENODEV;
257 
258 	memset(init, 0, sizeof(*init));
259 
260 	/*
261 	 * For now, we don't return any features.
262 	 * In future, we might use features to return target
263 	 * specific features available for the preferred
264 	 * target type.
265 	 */
266 	init->target = (__u32)target;
267 
268 	return 0;
269 }
270 
271 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
272 {
273 	return -EINVAL;
274 }
275 
276 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
277 {
278 	return -EINVAL;
279 }
280 
281 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
282 				  struct kvm_translation *tr)
283 {
284 	return -EINVAL;
285 }
286