[mirror_ubuntu-bionic-kernel.git] / virt / kvm / arm / psci.c

/*
 * Copyright (C) 2012 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/preempt.h>
#include <linux/kvm_host.h>
#include <linux/wait.h>

#include <asm/cputype.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_psci.h>
#include <asm/kvm_host.h>

#include <uapi/linux/psci.h>

/*
 * This is an implementation of the Power State Coordination Interface
 * as described in ARM document number ARM DEN 0022A.
 */

#define AFFINITY_MASK(level)	~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)

static unsigned long psci_affinity_mask(unsigned long affinity_level)
{
	if (affinity_level <= 3)
		return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);

	return 0;
}

static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
{
	/*
	 * NOTE: For simplicity, we make VCPU suspend emulation to be
	 * same-as WFI (Wait-for-interrupt) emulation.
	 *
	 * This means for KVM the wakeup events are interrupts and
	 * this is consistent with intended use of StateID as described
	 * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
	 *
	 * Further, we also treat power-down request to be same as
	 * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
	 * specification (ARM DEN 0022A). This means all suspend states
	 * for KVM will preserve the register state.
	 */
	kvm_vcpu_block(vcpu);
	kvm_clear_request(KVM_REQ_UNHALT, vcpu);

	return PSCI_RET_SUCCESS;
}

static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
{
	vcpu->arch.power_off = true;
	kvm_make_request(KVM_REQ_SLEEP, vcpu);
	kvm_vcpu_kick(vcpu);
}

static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
	struct kvm *kvm = source_vcpu->kvm;
	struct kvm_vcpu *vcpu = NULL;
	struct swait_queue_head *wq;
	unsigned long cpu_id;
	unsigned long context_id;
	phys_addr_t target_pc;

	cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
	if (vcpu_mode_is_32bit(source_vcpu))
		cpu_id &= ~((u32) 0);

	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);

	/*
	 * Make sure the caller requested a valid CPU and that the CPU is
	 * turned off.
	 */
	if (!vcpu)
		return PSCI_RET_INVALID_PARAMS;
	if (!vcpu->arch.power_off) {
		if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
			return PSCI_RET_ALREADY_ON;
		else
			return PSCI_RET_INVALID_PARAMS;
	}

	target_pc = vcpu_get_reg(source_vcpu, 2);
	context_id = vcpu_get_reg(source_vcpu, 3);

	kvm_reset_vcpu(vcpu);

	/* Gracefully handle Thumb2 entry point */
	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
		target_pc &= ~((phys_addr_t) 1);
		vcpu_set_thumb(vcpu);
	}

	/* Propagate caller endianness */
	if (kvm_vcpu_is_be(source_vcpu))
		kvm_vcpu_set_be(vcpu);

	*vcpu_pc(vcpu) = target_pc;
	/*
	 * NOTE: We always update r0 (or x0) because for PSCI v0.1
	 * the general puspose registers are undefined upon CPU_ON.
	 */
	vcpu_set_reg(vcpu, 0, context_id);
	vcpu->arch.power_off = false;
	smp_mb();		/* Make sure the above is visible */

	wq = kvm_arch_vcpu_wq(vcpu);
	swake_up(wq);

	return PSCI_RET_SUCCESS;
}

static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
{
	int i, matching_cpus = 0;
	unsigned long mpidr;
	unsigned long target_affinity;
	unsigned long target_affinity_mask;
	unsigned long lowest_affinity_level;
	struct kvm *kvm = vcpu->kvm;
	struct kvm_vcpu *tmp;

	target_affinity = vcpu_get_reg(vcpu, 1);
	lowest_affinity_level = vcpu_get_reg(vcpu, 2);

	/* Determine target affinity mask */
	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
	if (!target_affinity_mask)
		return PSCI_RET_INVALID_PARAMS;

	/* Ignore other bits of target affinity */
	target_affinity &= target_affinity_mask;

	/*
	 * If one or more VCPU matching target affinity are running
	 * then ON else OFF
	 */
	kvm_for_each_vcpu(i, tmp, kvm) {
		mpidr = kvm_vcpu_get_mpidr_aff(tmp);
		if ((mpidr & target_affinity_mask) == target_affinity) {
			matching_cpus++;
			if (!tmp->arch.power_off)
				return PSCI_0_2_AFFINITY_LEVEL_ON;
		}
	}

	if (!matching_cpus)
		return PSCI_RET_INVALID_PARAMS;

	return PSCI_0_2_AFFINITY_LEVEL_OFF;
}

static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
{
	int i;
	struct kvm_vcpu *tmp;

	/*
	 * The KVM ABI specifies that a system event exit may call KVM_RUN
	 * again and may perform shutdown/reboot at a later time that when the
	 * actual request is made.  Since we are implementing PSCI and a
	 * caller of PSCI reboot and shutdown expects that the system shuts
	 * down or reboots immediately, let's make sure that VCPUs are not run
	 * after this call is handled and before the VCPUs have been
	 * re-initialized.
	 */
	kvm_for_each_vcpu(i, tmp, vcpu->kvm)
		tmp->arch.power_off = true;
	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);

	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	vcpu->run->system_event.type = type;
	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
}

static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
{
	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
}

static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
{
	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
}

int kvm_psci_version(struct kvm_vcpu *vcpu)
{
	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
		return KVM_ARM_PSCI_0_2;

	return KVM_ARM_PSCI_0_1;
}

static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
	unsigned long val;
	int ret = 1;

	switch (psci_fn) {
	case PSCI_0_2_FN_PSCI_VERSION:
		/*
		 * Bits[31:16] = Major Version = 0
		 * Bits[15:0] = Minor Version = 2
		 */
		val = 2;
		break;
	case PSCI_0_2_FN_CPU_SUSPEND:
	case PSCI_0_2_FN64_CPU_SUSPEND:
		val = kvm_psci_vcpu_suspend(vcpu);
		break;
	case PSCI_0_2_FN_CPU_OFF:
		kvm_psci_vcpu_off(vcpu);
		val = PSCI_RET_SUCCESS;
		break;
	case PSCI_0_2_FN_CPU_ON:
	case PSCI_0_2_FN64_CPU_ON:
		mutex_lock(&kvm->lock);
		val = kvm_psci_vcpu_on(vcpu);
		mutex_unlock(&kvm->lock);
		break;
	case PSCI_0_2_FN_AFFINITY_INFO:
	case PSCI_0_2_FN64_AFFINITY_INFO:
		val = kvm_psci_vcpu_affinity_info(vcpu);
		break;
	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
		/*
		 * Trusted OS is MP hence does not require migration
	         * or
		 * Trusted OS is not present
		 */
		val = PSCI_0_2_TOS_MP;
		break;
	case PSCI_0_2_FN_SYSTEM_OFF:
		kvm_psci_system_off(vcpu);
		/*
		 * We should'nt be going back to guest VCPU after
		 * receiving SYSTEM_OFF request.
		 *
		 * If user space accidently/deliberately resumes
		 * guest VCPU after SYSTEM_OFF request then guest
		 * VCPU should see internal failure from PSCI return
		 * value. To achieve this, we preload r0 (or x0) with
		 * PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	case PSCI_0_2_FN_SYSTEM_RESET:
		kvm_psci_system_reset(vcpu);
		/*
		 * Same reason as SYSTEM_OFF for preloading r0 (or x0)
		 * with PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	default:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	}

	vcpu_set_reg(vcpu, 0, val);
	return ret;
}

static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
	unsigned long val;

	switch (psci_fn) {
	case KVM_PSCI_FN_CPU_OFF:
		kvm_psci_vcpu_off(vcpu);
		val = PSCI_RET_SUCCESS;
		break;
	case KVM_PSCI_FN_CPU_ON:
		mutex_lock(&kvm->lock);
		val = kvm_psci_vcpu_on(vcpu);
		mutex_unlock(&kvm->lock);
		break;
	default:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	}

	vcpu_set_reg(vcpu, 0, val);
	return 1;
}

/**
 * kvm_psci_call - handle PSCI call if r0 value is in range
 * @vcpu: Pointer to the VCPU struct
 *
 * Handle PSCI calls from guests through traps from HVC instructions.
 * The calling convention is similar to SMC calls to the secure world
 * where the function number is placed in r0.
 *
 * This function returns: > 0 (success), 0 (success but exit to user
 * space), and < 0 (errors)
 *
 * Errors:
 * -EINVAL: Unrecognized PSCI function
 */
int kvm_psci_call(struct kvm_vcpu *vcpu)
{
	switch (kvm_psci_version(vcpu)) {
	case KVM_ARM_PSCI_0_2:
		return kvm_psci_0_2_call(vcpu);
	case KVM_ARM_PSCI_0_1:
		return kvm_psci_0_1_call(vcpu);
	default:
		return -EINVAL;
	};
}
Commit	Line	Data
aa024c2f MZ	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
cf5d3188	18	#include <linux/preempt.h>
aa024c2f MZ	19	#include <linux/kvm_host.h>
	20	#include <linux/wait.h>
	21
79c64880	22	#include <asm/cputype.h>
aa024c2f MZ	23	#include <asm/kvm_emulate.h>
aa024c2f MZ	24	#include <asm/kvm_psci.h>
4429fc64	25	#include <asm/kvm_host.h>
aa024c2f	26
538b9b25 MR	27	#include <uapi/linux/psci.h>
538b9b25 MR	28
aa024c2f MZ	29	/*
	30	* This is an implementation of the Power State Coordination Interface
	31	* as described in ARM document number ARM DEN 0022A.
	32	*/
	33
e6bc13c8 AP	34	#define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
	35
	36	static unsigned long psci_affinity_mask(unsigned long affinity_level)
	37	{
	38	if (affinity_level <= 3)
	39	return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
	40
	41	return 0;
	42	}
	43
b376d02b AP	44	static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
	45	{
	46	/*
	47	* NOTE: For simplicity, we make VCPU suspend emulation to be
	48	* same-as WFI (Wait-for-interrupt) emulation.
	49	*
	50	* This means for KVM the wakeup events are interrupts and
	51	* this is consistent with intended use of StateID as described
	52	* in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
	53	*
	54	* Further, we also treat power-down request to be same as
	55	* stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
	56	* specification (ARM DEN 0022A). This means all suspend states
	57	* for KVM will preserve the register state.
	58	*/
	59	kvm_vcpu_block(vcpu);
6a6d73be	60	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
b376d02b AP	61
	62	return PSCI_RET_SUCCESS;
	63	}
	64
aa024c2f MZ	65	static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
aa024c2f MZ	66	{
3781528e	67	vcpu->arch.power_off = true;
7b244e2b	68	kvm_make_request(KVM_REQ_SLEEP, vcpu);
424c989b	69	kvm_vcpu_kick(vcpu);
aa024c2f MZ	70	}
	71
	72	static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
	73	{
	74	struct kvm *kvm = source_vcpu->kvm;
4429fc64	75	struct kvm_vcpu *vcpu = NULL;
8577370f	76	struct swait_queue_head *wq;
aa024c2f	77	unsigned long cpu_id;
aa8aeefe	78	unsigned long context_id;
aa024c2f MZ	79	phys_addr_t target_pc;
aa024c2f MZ	80
f6be563a	81	cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
aa024c2f MZ	82	if (vcpu_mode_is_32bit(source_vcpu))
	83	cpu_id &= ~((u32) 0);
	84
4429fc64	85	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
79c64880	86
478a8237 CD	87	/*
	88	* Make sure the caller requested a valid CPU and that the CPU is
	89	* turned off.
	90	*/
aa8aeefe	91	if (!vcpu)
7d0f84aa	92	return PSCI_RET_INVALID_PARAMS;
3781528e	93	if (!vcpu->arch.power_off) {
aa8aeefe AP	94	if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
	95	return PSCI_RET_ALREADY_ON;
	96	else
	97	return PSCI_RET_INVALID_PARAMS;
	98	}
aa024c2f	99
f6be563a PF	100	target_pc = vcpu_get_reg(source_vcpu, 2);
f6be563a PF	101	context_id = vcpu_get_reg(source_vcpu, 3);
aa024c2f	102
aa024c2f MZ	103	kvm_reset_vcpu(vcpu);
	104
	105	/* Gracefully handle Thumb2 entry point */
	106	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
	107	target_pc &= ~((phys_addr_t) 1);
	108	vcpu_set_thumb(vcpu);
	109	}
	110
ce94fe93 MZ	111	/* Propagate caller endianness */
	112	if (kvm_vcpu_is_be(source_vcpu))
	113	kvm_vcpu_set_be(vcpu);
	114
aa024c2f	115	*vcpu_pc(vcpu) = target_pc;
aa8aeefe AP	116	/*
	117	* NOTE: We always update r0 (or x0) because for PSCI v0.1
	118	* the general puspose registers are undefined upon CPU_ON.
	119	*/
f6be563a	120	vcpu_set_reg(vcpu, 0, context_id);
3781528e	121	vcpu->arch.power_off = false;
aa024c2f MZ	122	smp_mb(); /* Make sure the above is visible */
aa024c2f MZ	123
478a8237	124	wq = kvm_arch_vcpu_wq(vcpu);
8577370f	125	swake_up(wq);
aa024c2f	126
7d0f84aa	127	return PSCI_RET_SUCCESS;
aa024c2f MZ	128	}
aa024c2f MZ	129
e6bc13c8 AP	130	static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
e6bc13c8 AP	131	{
0c067292	132	int i, matching_cpus = 0;
e6bc13c8 AP	133	unsigned long mpidr;
	134	unsigned long target_affinity;
	135	unsigned long target_affinity_mask;
	136	unsigned long lowest_affinity_level;
	137	struct kvm *kvm = vcpu->kvm;
	138	struct kvm_vcpu *tmp;
	139
f6be563a PF	140	target_affinity = vcpu_get_reg(vcpu, 1);
f6be563a PF	141	lowest_affinity_level = vcpu_get_reg(vcpu, 2);
e6bc13c8 AP	142
	143	/* Determine target affinity mask */
	144	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
	145	if (!target_affinity_mask)
	146	return PSCI_RET_INVALID_PARAMS;
	147
	148	/* Ignore other bits of target affinity */
	149	target_affinity &= target_affinity_mask;
	150
	151	/*
	152	* If one or more VCPU matching target affinity are running
	153	* then ON else OFF
	154	*/
	155	kvm_for_each_vcpu(i, tmp, kvm) {
4429fc64	156	mpidr = kvm_vcpu_get_mpidr_aff(tmp);
0c067292 AS	157	if ((mpidr & target_affinity_mask) == target_affinity) {
0c067292 AS	158	matching_cpus++;
3781528e	159	if (!tmp->arch.power_off)
0c067292	160	return PSCI_0_2_AFFINITY_LEVEL_ON;
e6bc13c8 AP	161	}
	162	}
	163
0c067292 AS	164	if (!matching_cpus)
	165	return PSCI_RET_INVALID_PARAMS;
	166
e6bc13c8 AP	167	return PSCI_0_2_AFFINITY_LEVEL_OFF;
	168	}
	169
4b123826 AP	170	static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
4b123826 AP	171	{
cf5d3188 CD	172	int i;
	173	struct kvm_vcpu *tmp;
	174
	175	/*
	176	* The KVM ABI specifies that a system event exit may call KVM_RUN
	177	* again and may perform shutdown/reboot at a later time that when the
	178	* actual request is made. Since we are implementing PSCI and a
	179	* caller of PSCI reboot and shutdown expects that the system shuts
	180	* down or reboots immediately, let's make sure that VCPUs are not run
	181	* after this call is handled and before the VCPUs have been
	182	* re-initialized.
	183	*/
cc9b43f9	184	kvm_for_each_vcpu(i, tmp, vcpu->kvm)
3781528e	185	tmp->arch.power_off = true;
7b244e2b	186	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
cf5d3188	187
4b123826 AP	188	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	189	vcpu->run->system_event.type = type;
	190	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
	191	}
	192
	193	static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
	194	{
	195	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
	196	}
	197
	198	static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
	199	{
	200	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
	201	}
	202
7d0f84aa AP	203	int kvm_psci_version(struct kvm_vcpu *vcpu)
	204	{
	205	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
	206	return KVM_ARM_PSCI_0_2;
	207
	208	return KVM_ARM_PSCI_0_1;
	209	}
	210
e8e7fcc5	211	static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
7d0f84aa	212	{
6c7a5dce	213	struct kvm *kvm = vcpu->kvm;
f6be563a	214	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
7d0f84aa	215	unsigned long val;
6c7a5dce	216	int ret = 1;
7d0f84aa AP	217
	218	switch (psci_fn) {
	219	case PSCI_0_2_FN_PSCI_VERSION:
	220	/*
	221	* Bits[31:16] = Major Version = 0
	222	* Bits[15:0] = Minor Version = 2
	223	*/
	224	val = 2;
	225	break;
b376d02b AP	226	case PSCI_0_2_FN_CPU_SUSPEND:
	227	case PSCI_0_2_FN64_CPU_SUSPEND:
	228	val = kvm_psci_vcpu_suspend(vcpu);
	229	break;
7d0f84aa AP	230	case PSCI_0_2_FN_CPU_OFF:
	231	kvm_psci_vcpu_off(vcpu);
	232	val = PSCI_RET_SUCCESS;
	233	break;
	234	case PSCI_0_2_FN_CPU_ON:
	235	case PSCI_0_2_FN64_CPU_ON:
6c7a5dce	236	mutex_lock(&kvm->lock);
7d0f84aa	237	val = kvm_psci_vcpu_on(vcpu);
6c7a5dce	238	mutex_unlock(&kvm->lock);
7d0f84aa	239	break;
e6bc13c8 AP	240	case PSCI_0_2_FN_AFFINITY_INFO:
	241	case PSCI_0_2_FN64_AFFINITY_INFO:
	242	val = kvm_psci_vcpu_affinity_info(vcpu);
	243	break;
bab0b430 AP	244	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	245	/*
	246	* Trusted OS is MP hence does not require migration
	247	* or
	248	* Trusted OS is not present
	249	*/
	250	val = PSCI_0_2_TOS_MP;
	251	break;
4b123826 AP	252	case PSCI_0_2_FN_SYSTEM_OFF:
	253	kvm_psci_system_off(vcpu);
	254	/*
	255	* We should'nt be going back to guest VCPU after
	256	* receiving SYSTEM_OFF request.
	257	*
	258	* If user space accidently/deliberately resumes
	259	* guest VCPU after SYSTEM_OFF request then guest
	260	* VCPU should see internal failure from PSCI return
	261	* value. To achieve this, we preload r0 (or x0) with
	262	* PSCI return value INTERNAL_FAILURE.
	263	*/
	264	val = PSCI_RET_INTERNAL_FAILURE;
	265	ret = 0;
	266	break;
	267	case PSCI_0_2_FN_SYSTEM_RESET:
	268	kvm_psci_system_reset(vcpu);
	269	/*
	270	* Same reason as SYSTEM_OFF for preloading r0 (or x0)
	271	* with PSCI return value INTERNAL_FAILURE.
	272	*/
	273	val = PSCI_RET_INTERNAL_FAILURE;
	274	ret = 0;
	275	break;
7d0f84aa	276	default:
e2d99736 LP	277	val = PSCI_RET_NOT_SUPPORTED;
e2d99736 LP	278	break;
7d0f84aa AP	279	}
7d0f84aa AP	280
f6be563a	281	vcpu_set_reg(vcpu, 0, val);
4b123826	282	return ret;
7d0f84aa AP	283	}
7d0f84aa AP	284
e8e7fcc5	285	static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
aa024c2f	286	{
6c7a5dce	287	struct kvm *kvm = vcpu->kvm;
f6be563a	288	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
aa024c2f MZ	289	unsigned long val;
	290
	291	switch (psci_fn) {
	292	case KVM_PSCI_FN_CPU_OFF:
	293	kvm_psci_vcpu_off(vcpu);
7d0f84aa	294	val = PSCI_RET_SUCCESS;
aa024c2f MZ	295	break;
aa024c2f MZ	296	case KVM_PSCI_FN_CPU_ON:
6c7a5dce	297	mutex_lock(&kvm->lock);
aa024c2f	298	val = kvm_psci_vcpu_on(vcpu);
6c7a5dce	299	mutex_unlock(&kvm->lock);
aa024c2f	300	break;
e2d99736	301	default:
7d0f84aa	302	val = PSCI_RET_NOT_SUPPORTED;
aa024c2f	303	break;
aa024c2f MZ	304	}
aa024c2f MZ	305
f6be563a	306	vcpu_set_reg(vcpu, 0, val);
e8e7fcc5	307	return 1;
aa024c2f	308	}
7d0f84aa AP	309
	310	/**
	311	* kvm_psci_call - handle PSCI call if r0 value is in range
	312	* @vcpu: Pointer to the VCPU struct
	313	*
	314	* Handle PSCI calls from guests through traps from HVC instructions.
e8e7fcc5 AP	315	* The calling convention is similar to SMC calls to the secure world
	316	* where the function number is placed in r0.
	317	*
	318	* This function returns: > 0 (success), 0 (success but exit to user
	319	* space), and < 0 (errors)
	320	*
	321	* Errors:
	322	* -EINVAL: Unrecognized PSCI function
7d0f84aa	323	*/
e8e7fcc5	324	int kvm_psci_call(struct kvm_vcpu *vcpu)
7d0f84aa AP	325	{
	326	switch (kvm_psci_version(vcpu)) {
	327	case KVM_ARM_PSCI_0_2:
	328	return kvm_psci_0_2_call(vcpu);
	329	case KVM_ARM_PSCI_0_1:
	330	return kvm_psci_0_1_call(vcpu);
	331	default:
e8e7fcc5	332	return -EINVAL;
7d0f84aa AP	333	};
7d0f84aa AP	334	}