2 * Copyright (C) 2012 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
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.
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.
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/>.
18 #include <linux/kvm_host.h>
19 #include <linux/wait.h>
21 #include <asm/cputype.h>
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_psci.h>
26 * This is an implementation of the Power State Coordination Interface
27 * as described in ARM document number ARM DEN 0022A.
30 #define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
32 static unsigned long psci_affinity_mask(unsigned long affinity_level)
34 if (affinity_level <= 3)
35 return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
40 static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
42 vcpu->arch.pause = true;
45 static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
47 struct kvm *kvm = source_vcpu->kvm;
48 struct kvm_vcpu *vcpu = NULL, *tmp;
49 wait_queue_head_t *wq;
52 phys_addr_t target_pc;
55 cpu_id = *vcpu_reg(source_vcpu, 1);
56 if (vcpu_mode_is_32bit(source_vcpu))
59 kvm_for_each_vcpu(i, tmp, kvm) {
60 mpidr = kvm_vcpu_get_mpidr(tmp);
61 if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
68 * Make sure the caller requested a valid CPU and that the CPU is
71 if (!vcpu || !vcpu->arch.pause)
72 return PSCI_RET_INVALID_PARAMS;
74 target_pc = *vcpu_reg(source_vcpu, 2);
78 /* Gracefully handle Thumb2 entry point */
79 if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
80 target_pc &= ~((phys_addr_t) 1);
84 /* Propagate caller endianness */
85 if (kvm_vcpu_is_be(source_vcpu))
86 kvm_vcpu_set_be(vcpu);
88 *vcpu_pc(vcpu) = target_pc;
89 vcpu->arch.pause = false;
90 smp_mb(); /* Make sure the above is visible */
92 wq = kvm_arch_vcpu_wq(vcpu);
93 wake_up_interruptible(wq);
95 return PSCI_RET_SUCCESS;
98 static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
102 unsigned long target_affinity;
103 unsigned long target_affinity_mask;
104 unsigned long lowest_affinity_level;
105 struct kvm *kvm = vcpu->kvm;
106 struct kvm_vcpu *tmp;
108 target_affinity = *vcpu_reg(vcpu, 1);
109 lowest_affinity_level = *vcpu_reg(vcpu, 2);
111 /* Determine target affinity mask */
112 target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
113 if (!target_affinity_mask)
114 return PSCI_RET_INVALID_PARAMS;
116 /* Ignore other bits of target affinity */
117 target_affinity &= target_affinity_mask;
120 * If one or more VCPU matching target affinity are running
123 kvm_for_each_vcpu(i, tmp, kvm) {
124 mpidr = kvm_vcpu_get_mpidr(tmp);
125 if (((mpidr & target_affinity_mask) == target_affinity) &&
127 return PSCI_0_2_AFFINITY_LEVEL_ON;
131 return PSCI_0_2_AFFINITY_LEVEL_OFF;
134 static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
136 memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
137 vcpu->run->system_event.type = type;
138 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
141 static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
143 kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
146 static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
148 kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
151 int kvm_psci_version(struct kvm_vcpu *vcpu)
153 if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
154 return KVM_ARM_PSCI_0_2;
156 return KVM_ARM_PSCI_0_1;
159 static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
162 unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
166 case PSCI_0_2_FN_PSCI_VERSION:
168 * Bits[31:16] = Major Version = 0
169 * Bits[15:0] = Minor Version = 2
173 case PSCI_0_2_FN_CPU_OFF:
174 kvm_psci_vcpu_off(vcpu);
175 val = PSCI_RET_SUCCESS;
177 case PSCI_0_2_FN_CPU_ON:
178 case PSCI_0_2_FN64_CPU_ON:
179 val = kvm_psci_vcpu_on(vcpu);
181 case PSCI_0_2_FN_AFFINITY_INFO:
182 case PSCI_0_2_FN64_AFFINITY_INFO:
183 val = kvm_psci_vcpu_affinity_info(vcpu);
185 case PSCI_0_2_FN_SYSTEM_OFF:
186 kvm_psci_system_off(vcpu);
188 * We should'nt be going back to guest VCPU after
189 * receiving SYSTEM_OFF request.
191 * If user space accidently/deliberately resumes
192 * guest VCPU after SYSTEM_OFF request then guest
193 * VCPU should see internal failure from PSCI return
194 * value. To achieve this, we preload r0 (or x0) with
195 * PSCI return value INTERNAL_FAILURE.
197 val = PSCI_RET_INTERNAL_FAILURE;
200 case PSCI_0_2_FN_SYSTEM_RESET:
201 kvm_psci_system_reset(vcpu);
203 * Same reason as SYSTEM_OFF for preloading r0 (or x0)
204 * with PSCI return value INTERNAL_FAILURE.
206 val = PSCI_RET_INTERNAL_FAILURE;
209 case PSCI_0_2_FN_CPU_SUSPEND:
210 case PSCI_0_2_FN_MIGRATE:
211 case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
212 case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
213 case PSCI_0_2_FN64_CPU_SUSPEND:
214 case PSCI_0_2_FN64_MIGRATE:
215 case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
216 val = PSCI_RET_NOT_SUPPORTED;
222 *vcpu_reg(vcpu, 0) = val;
226 static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
228 unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
232 case KVM_PSCI_FN_CPU_OFF:
233 kvm_psci_vcpu_off(vcpu);
234 val = PSCI_RET_SUCCESS;
236 case KVM_PSCI_FN_CPU_ON:
237 val = kvm_psci_vcpu_on(vcpu);
239 case KVM_PSCI_FN_CPU_SUSPEND:
240 case KVM_PSCI_FN_MIGRATE:
241 val = PSCI_RET_NOT_SUPPORTED;
247 *vcpu_reg(vcpu, 0) = val;
252 * kvm_psci_call - handle PSCI call if r0 value is in range
253 * @vcpu: Pointer to the VCPU struct
255 * Handle PSCI calls from guests through traps from HVC instructions.
256 * The calling convention is similar to SMC calls to the secure world
257 * where the function number is placed in r0.
259 * This function returns: > 0 (success), 0 (success but exit to user
260 * space), and < 0 (errors)
263 * -EINVAL: Unrecognized PSCI function
265 int kvm_psci_call(struct kvm_vcpu *vcpu)
267 switch (kvm_psci_version(vcpu)) {
268 case KVM_ARM_PSCI_0_2:
269 return kvm_psci_0_2_call(vcpu);
270 case KVM_ARM_PSCI_0_1:
271 return kvm_psci_0_1_call(vcpu);