Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 - ARM Ltd |
| 3 | * Author: Marc Zyngier <marc.zyngier@arm.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | */ |
| 17 | |
Christoffer Dall | cf5d3188 | 2014-10-16 17:00:18 +0200 | [diff] [blame] | 18 | #include <linux/preempt.h> |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 19 | #include <linux/kvm_host.h> |
| 20 | #include <linux/wait.h> |
| 21 | |
Marc Zyngier | 79c6488 | 2013-10-18 18:19:03 +0100 | [diff] [blame] | 22 | #include <asm/cputype.h> |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 23 | #include <asm/kvm_emulate.h> |
| 24 | #include <asm/kvm_psci.h> |
Andre Przywara | 4429fc6 | 2014-06-02 15:37:13 +0200 | [diff] [blame] | 25 | #include <asm/kvm_host.h> |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 26 | |
| 27 | /* |
| 28 | * This is an implementation of the Power State Coordination Interface |
| 29 | * as described in ARM document number ARM DEN 0022A. |
| 30 | */ |
| 31 | |
Anup Patel | e6bc13c | 2014-04-29 11:24:21 +0530 | [diff] [blame] | 32 | #define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1) |
| 33 | |
| 34 | static unsigned long psci_affinity_mask(unsigned long affinity_level) |
| 35 | { |
| 36 | if (affinity_level <= 3) |
| 37 | return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level); |
| 38 | |
| 39 | return 0; |
| 40 | } |
| 41 | |
Anup Patel | b376d02 | 2014-04-29 11:24:24 +0530 | [diff] [blame] | 42 | static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) |
| 43 | { |
| 44 | /* |
| 45 | * NOTE: For simplicity, we make VCPU suspend emulation to be |
| 46 | * same-as WFI (Wait-for-interrupt) emulation. |
| 47 | * |
| 48 | * This means for KVM the wakeup events are interrupts and |
| 49 | * this is consistent with intended use of StateID as described |
| 50 | * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A). |
| 51 | * |
| 52 | * Further, we also treat power-down request to be same as |
| 53 | * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2 |
| 54 | * specification (ARM DEN 0022A). This means all suspend states |
| 55 | * for KVM will preserve the register state. |
| 56 | */ |
| 57 | kvm_vcpu_block(vcpu); |
| 58 | |
| 59 | return PSCI_RET_SUCCESS; |
| 60 | } |
| 61 | |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 62 | static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) |
| 63 | { |
| 64 | vcpu->arch.pause = true; |
| 65 | } |
| 66 | |
| 67 | static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) |
| 68 | { |
| 69 | struct kvm *kvm = source_vcpu->kvm; |
Andre Przywara | 4429fc6 | 2014-06-02 15:37:13 +0200 | [diff] [blame] | 70 | struct kvm_vcpu *vcpu = NULL; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 71 | wait_queue_head_t *wq; |
| 72 | unsigned long cpu_id; |
Anup Patel | aa8aeef | 2014-04-29 11:24:23 +0530 | [diff] [blame] | 73 | unsigned long context_id; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 74 | phys_addr_t target_pc; |
| 75 | |
Andre Przywara | 4429fc6 | 2014-06-02 15:37:13 +0200 | [diff] [blame] | 76 | cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 77 | if (vcpu_mode_is_32bit(source_vcpu)) |
| 78 | cpu_id &= ~((u32) 0); |
| 79 | |
Andre Przywara | 4429fc6 | 2014-06-02 15:37:13 +0200 | [diff] [blame] | 80 | vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id); |
Marc Zyngier | 79c6488 | 2013-10-18 18:19:03 +0100 | [diff] [blame] | 81 | |
Christoffer Dall | 478a823 | 2013-11-19 17:43:19 -0800 | [diff] [blame] | 82 | /* |
| 83 | * Make sure the caller requested a valid CPU and that the CPU is |
| 84 | * turned off. |
| 85 | */ |
Anup Patel | aa8aeef | 2014-04-29 11:24:23 +0530 | [diff] [blame] | 86 | if (!vcpu) |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 87 | return PSCI_RET_INVALID_PARAMS; |
Anup Patel | aa8aeef | 2014-04-29 11:24:23 +0530 | [diff] [blame] | 88 | if (!vcpu->arch.pause) { |
| 89 | if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) |
| 90 | return PSCI_RET_ALREADY_ON; |
| 91 | else |
| 92 | return PSCI_RET_INVALID_PARAMS; |
| 93 | } |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 94 | |
| 95 | target_pc = *vcpu_reg(source_vcpu, 2); |
Anup Patel | aa8aeef | 2014-04-29 11:24:23 +0530 | [diff] [blame] | 96 | context_id = *vcpu_reg(source_vcpu, 3); |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 97 | |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 98 | kvm_reset_vcpu(vcpu); |
| 99 | |
| 100 | /* Gracefully handle Thumb2 entry point */ |
| 101 | if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { |
| 102 | target_pc &= ~((phys_addr_t) 1); |
| 103 | vcpu_set_thumb(vcpu); |
| 104 | } |
| 105 | |
Marc Zyngier | ce94fe9 | 2013-11-05 14:12:15 +0000 | [diff] [blame] | 106 | /* Propagate caller endianness */ |
| 107 | if (kvm_vcpu_is_be(source_vcpu)) |
| 108 | kvm_vcpu_set_be(vcpu); |
| 109 | |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 110 | *vcpu_pc(vcpu) = target_pc; |
Anup Patel | aa8aeef | 2014-04-29 11:24:23 +0530 | [diff] [blame] | 111 | /* |
| 112 | * NOTE: We always update r0 (or x0) because for PSCI v0.1 |
| 113 | * the general puspose registers are undefined upon CPU_ON. |
| 114 | */ |
| 115 | *vcpu_reg(vcpu, 0) = context_id; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 116 | vcpu->arch.pause = false; |
| 117 | smp_mb(); /* Make sure the above is visible */ |
| 118 | |
Christoffer Dall | 478a823 | 2013-11-19 17:43:19 -0800 | [diff] [blame] | 119 | wq = kvm_arch_vcpu_wq(vcpu); |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 120 | wake_up_interruptible(wq); |
| 121 | |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 122 | return PSCI_RET_SUCCESS; |
| 123 | } |
| 124 | |
Anup Patel | e6bc13c | 2014-04-29 11:24:21 +0530 | [diff] [blame] | 125 | static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) |
| 126 | { |
| 127 | int i; |
| 128 | unsigned long mpidr; |
| 129 | unsigned long target_affinity; |
| 130 | unsigned long target_affinity_mask; |
| 131 | unsigned long lowest_affinity_level; |
| 132 | struct kvm *kvm = vcpu->kvm; |
| 133 | struct kvm_vcpu *tmp; |
| 134 | |
| 135 | target_affinity = *vcpu_reg(vcpu, 1); |
| 136 | lowest_affinity_level = *vcpu_reg(vcpu, 2); |
| 137 | |
| 138 | /* Determine target affinity mask */ |
| 139 | target_affinity_mask = psci_affinity_mask(lowest_affinity_level); |
| 140 | if (!target_affinity_mask) |
| 141 | return PSCI_RET_INVALID_PARAMS; |
| 142 | |
| 143 | /* Ignore other bits of target affinity */ |
| 144 | target_affinity &= target_affinity_mask; |
| 145 | |
| 146 | /* |
| 147 | * If one or more VCPU matching target affinity are running |
| 148 | * then ON else OFF |
| 149 | */ |
| 150 | kvm_for_each_vcpu(i, tmp, kvm) { |
Andre Przywara | 4429fc6 | 2014-06-02 15:37:13 +0200 | [diff] [blame] | 151 | mpidr = kvm_vcpu_get_mpidr_aff(tmp); |
Anup Patel | e6bc13c | 2014-04-29 11:24:21 +0530 | [diff] [blame] | 152 | if (((mpidr & target_affinity_mask) == target_affinity) && |
| 153 | !tmp->arch.pause) { |
| 154 | return PSCI_0_2_AFFINITY_LEVEL_ON; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | return PSCI_0_2_AFFINITY_LEVEL_OFF; |
| 159 | } |
| 160 | |
Anup Patel | 4b12382 | 2014-04-29 11:24:20 +0530 | [diff] [blame] | 161 | static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) |
| 162 | { |
Christoffer Dall | cf5d3188 | 2014-10-16 17:00:18 +0200 | [diff] [blame] | 163 | int i; |
| 164 | struct kvm_vcpu *tmp; |
| 165 | |
| 166 | /* |
| 167 | * The KVM ABI specifies that a system event exit may call KVM_RUN |
| 168 | * again and may perform shutdown/reboot at a later time that when the |
| 169 | * actual request is made. Since we are implementing PSCI and a |
| 170 | * caller of PSCI reboot and shutdown expects that the system shuts |
| 171 | * down or reboots immediately, let's make sure that VCPUs are not run |
| 172 | * after this call is handled and before the VCPUs have been |
| 173 | * re-initialized. |
| 174 | */ |
| 175 | kvm_for_each_vcpu(i, tmp, vcpu->kvm) { |
| 176 | tmp->arch.pause = true; |
| 177 | kvm_vcpu_kick(tmp); |
| 178 | } |
| 179 | |
Anup Patel | 4b12382 | 2014-04-29 11:24:20 +0530 | [diff] [blame] | 180 | memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); |
| 181 | vcpu->run->system_event.type = type; |
| 182 | vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; |
| 183 | } |
| 184 | |
| 185 | static void kvm_psci_system_off(struct kvm_vcpu *vcpu) |
| 186 | { |
| 187 | kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); |
| 188 | } |
| 189 | |
| 190 | static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) |
| 191 | { |
| 192 | kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); |
| 193 | } |
| 194 | |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 195 | int kvm_psci_version(struct kvm_vcpu *vcpu) |
| 196 | { |
| 197 | if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) |
| 198 | return KVM_ARM_PSCI_0_2; |
| 199 | |
| 200 | return KVM_ARM_PSCI_0_1; |
| 201 | } |
| 202 | |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 203 | static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 204 | { |
Anup Patel | 4b12382 | 2014-04-29 11:24:20 +0530 | [diff] [blame] | 205 | int ret = 1; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 206 | unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); |
| 207 | unsigned long val; |
| 208 | |
| 209 | switch (psci_fn) { |
| 210 | case PSCI_0_2_FN_PSCI_VERSION: |
| 211 | /* |
| 212 | * Bits[31:16] = Major Version = 0 |
| 213 | * Bits[15:0] = Minor Version = 2 |
| 214 | */ |
| 215 | val = 2; |
| 216 | break; |
Anup Patel | b376d02 | 2014-04-29 11:24:24 +0530 | [diff] [blame] | 217 | case PSCI_0_2_FN_CPU_SUSPEND: |
| 218 | case PSCI_0_2_FN64_CPU_SUSPEND: |
| 219 | val = kvm_psci_vcpu_suspend(vcpu); |
| 220 | break; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 221 | case PSCI_0_2_FN_CPU_OFF: |
| 222 | kvm_psci_vcpu_off(vcpu); |
| 223 | val = PSCI_RET_SUCCESS; |
| 224 | break; |
| 225 | case PSCI_0_2_FN_CPU_ON: |
| 226 | case PSCI_0_2_FN64_CPU_ON: |
| 227 | val = kvm_psci_vcpu_on(vcpu); |
| 228 | break; |
Anup Patel | e6bc13c | 2014-04-29 11:24:21 +0530 | [diff] [blame] | 229 | case PSCI_0_2_FN_AFFINITY_INFO: |
| 230 | case PSCI_0_2_FN64_AFFINITY_INFO: |
| 231 | val = kvm_psci_vcpu_affinity_info(vcpu); |
| 232 | break; |
Anup Patel | bab0b430 | 2014-04-29 11:24:22 +0530 | [diff] [blame] | 233 | case PSCI_0_2_FN_MIGRATE: |
| 234 | case PSCI_0_2_FN64_MIGRATE: |
| 235 | val = PSCI_RET_NOT_SUPPORTED; |
| 236 | break; |
| 237 | case PSCI_0_2_FN_MIGRATE_INFO_TYPE: |
| 238 | /* |
| 239 | * Trusted OS is MP hence does not require migration |
| 240 | * or |
| 241 | * Trusted OS is not present |
| 242 | */ |
| 243 | val = PSCI_0_2_TOS_MP; |
| 244 | break; |
| 245 | case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: |
| 246 | case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: |
| 247 | val = PSCI_RET_NOT_SUPPORTED; |
| 248 | break; |
Anup Patel | 4b12382 | 2014-04-29 11:24:20 +0530 | [diff] [blame] | 249 | case PSCI_0_2_FN_SYSTEM_OFF: |
| 250 | kvm_psci_system_off(vcpu); |
| 251 | /* |
| 252 | * We should'nt be going back to guest VCPU after |
| 253 | * receiving SYSTEM_OFF request. |
| 254 | * |
| 255 | * If user space accidently/deliberately resumes |
| 256 | * guest VCPU after SYSTEM_OFF request then guest |
| 257 | * VCPU should see internal failure from PSCI return |
| 258 | * value. To achieve this, we preload r0 (or x0) with |
| 259 | * PSCI return value INTERNAL_FAILURE. |
| 260 | */ |
| 261 | val = PSCI_RET_INTERNAL_FAILURE; |
| 262 | ret = 0; |
| 263 | break; |
| 264 | case PSCI_0_2_FN_SYSTEM_RESET: |
| 265 | kvm_psci_system_reset(vcpu); |
| 266 | /* |
| 267 | * Same reason as SYSTEM_OFF for preloading r0 (or x0) |
| 268 | * with PSCI return value INTERNAL_FAILURE. |
| 269 | */ |
| 270 | val = PSCI_RET_INTERNAL_FAILURE; |
| 271 | ret = 0; |
| 272 | break; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 273 | default: |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 274 | return -EINVAL; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 275 | } |
| 276 | |
| 277 | *vcpu_reg(vcpu, 0) = val; |
Anup Patel | 4b12382 | 2014-04-29 11:24:20 +0530 | [diff] [blame] | 278 | return ret; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 279 | } |
| 280 | |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 281 | static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 282 | { |
| 283 | unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); |
| 284 | unsigned long val; |
| 285 | |
| 286 | switch (psci_fn) { |
| 287 | case KVM_PSCI_FN_CPU_OFF: |
| 288 | kvm_psci_vcpu_off(vcpu); |
| 289 | val = PSCI_RET_SUCCESS; |
| 290 | break; |
| 291 | case KVM_PSCI_FN_CPU_ON: |
| 292 | val = kvm_psci_vcpu_on(vcpu); |
| 293 | break; |
| 294 | case KVM_PSCI_FN_CPU_SUSPEND: |
| 295 | case KVM_PSCI_FN_MIGRATE: |
| 296 | val = PSCI_RET_NOT_SUPPORTED; |
| 297 | break; |
| 298 | default: |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 299 | return -EINVAL; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 300 | } |
| 301 | |
| 302 | *vcpu_reg(vcpu, 0) = val; |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 303 | return 1; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 304 | } |
| 305 | |
| 306 | /** |
| 307 | * kvm_psci_call - handle PSCI call if r0 value is in range |
| 308 | * @vcpu: Pointer to the VCPU struct |
| 309 | * |
Dave P Martin | 24a7f67 | 2013-05-01 17:49:28 +0100 | [diff] [blame] | 310 | * Handle PSCI calls from guests through traps from HVC instructions. |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 311 | * The calling convention is similar to SMC calls to the secure world |
| 312 | * where the function number is placed in r0. |
| 313 | * |
| 314 | * This function returns: > 0 (success), 0 (success but exit to user |
| 315 | * space), and < 0 (errors) |
| 316 | * |
| 317 | * Errors: |
| 318 | * -EINVAL: Unrecognized PSCI function |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 319 | */ |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 320 | int kvm_psci_call(struct kvm_vcpu *vcpu) |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 321 | { |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 322 | switch (kvm_psci_version(vcpu)) { |
| 323 | case KVM_ARM_PSCI_0_2: |
| 324 | return kvm_psci_0_2_call(vcpu); |
| 325 | case KVM_ARM_PSCI_0_1: |
| 326 | return kvm_psci_0_1_call(vcpu); |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 327 | default: |
Anup Patel | e8e7fcc | 2014-04-29 11:24:18 +0530 | [diff] [blame] | 328 | return -EINVAL; |
Anup Patel | 7d0f84a | 2014-04-29 11:24:16 +0530 | [diff] [blame] | 329 | }; |
Marc Zyngier | aa024c2f | 2013-01-20 18:28:13 -0500 | [diff] [blame] | 330 | } |