[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/arm-smccc.h>
#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_host.h>

#include <kvm/arm_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 u32 smccc_get_function(struct kvm_vcpu *vcpu)
{
	return vcpu_get_reg(vcpu, 0);
}

static unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu)
{
	return vcpu_get_reg(vcpu, 1);
}

static unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu)
{
	return vcpu_get_reg(vcpu, 2);
}

static unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu)
{
	return vcpu_get_reg(vcpu, 3);
}

static void smccc_set_retval(struct kvm_vcpu *vcpu,
			     unsigned long a0,
			     unsigned long a1,
			     unsigned long a2,
			     unsigned long a3)
{
	vcpu_set_reg(vcpu, 0, a0);
	vcpu_set_reg(vcpu, 1, a1);
	vcpu_set_reg(vcpu, 2, a2);
	vcpu_set_reg(vcpu, 3, a3);
}

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 = smccc_get_arg1(source_vcpu) & 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) != KVM_ARM_PSCI_0_1)
			return PSCI_RET_ALREADY_ON;
		else
			return PSCI_RET_INVALID_PARAMS;
	}

	target_pc = smccc_get_arg2(source_vcpu);
	context_id = smccc_get_arg3(source_vcpu);

	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.
	 */
	smccc_set_retval(vcpu, context_id, 0, 0, 0);
	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 = smccc_get_arg1(vcpu);
	lowest_affinity_level = smccc_get_arg2(vcpu);

	/* 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);
}

static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	u32 psci_fn = smccc_get_function(vcpu);
	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 = KVM_ARM_PSCI_0_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;
	}

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

static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu)
{
	u32 psci_fn = smccc_get_function(vcpu);
	u32 feature;
	unsigned long val;
	int ret = 1;

	switch(psci_fn) {
	case PSCI_0_2_FN_PSCI_VERSION:
		val = KVM_ARM_PSCI_1_0;
		break;
	case PSCI_1_0_FN_PSCI_FEATURES:
		feature = smccc_get_arg1(vcpu);
		switch(feature) {
		case PSCI_0_2_FN_PSCI_VERSION:
		case PSCI_0_2_FN_CPU_SUSPEND:
		case PSCI_0_2_FN64_CPU_SUSPEND:
		case PSCI_0_2_FN_CPU_OFF:
		case PSCI_0_2_FN_CPU_ON:
		case PSCI_0_2_FN64_CPU_ON:
		case PSCI_0_2_FN_AFFINITY_INFO:
		case PSCI_0_2_FN64_AFFINITY_INFO:
		case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
		case PSCI_0_2_FN_SYSTEM_OFF:
		case PSCI_0_2_FN_SYSTEM_RESET:
		case PSCI_1_0_FN_PSCI_FEATURES:
		case ARM_SMCCC_VERSION_FUNC_ID:
			val = 0;
			break;
		default:
			val = PSCI_RET_NOT_SUPPORTED;
			break;
		}
		break;
	default:
		return kvm_psci_0_2_call(vcpu);
	}

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

static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	u32 psci_fn = smccc_get_function(vcpu);
	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;
	}

	smccc_set_retval(vcpu, val, 0, 0, 0);
	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
 */
static int kvm_psci_call(struct kvm_vcpu *vcpu)
{
	switch (kvm_psci_version(vcpu, vcpu->kvm)) {
	case KVM_ARM_PSCI_1_0:
		return kvm_psci_1_0_call(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;
	};
}

int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
{
	u32 func_id = smccc_get_function(vcpu);
	u32 val = PSCI_RET_NOT_SUPPORTED;
	u32 feature;

	switch (func_id) {
	case ARM_SMCCC_VERSION_FUNC_ID:
		val = ARM_SMCCC_VERSION_1_1;
		break;
	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
		feature = smccc_get_arg1(vcpu);
		switch(feature) {
		case ARM_SMCCC_ARCH_WORKAROUND_1:
			if (kvm_arm_harden_branch_predictor())
				val = 0;
			break;
		}
		break;
	default:
		return kvm_psci_call(vcpu);
	}

	smccc_set_retval(vcpu, val, 0, 0, 0);
	return 1;
}
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
7b5b30e9	18	#include <linux/arm-smccc.h>
cf5d3188	19	#include <linux/preempt.h>
aa024c2f MZ	20	#include <linux/kvm_host.h>
	21	#include <linux/wait.h>
	22
79c64880	23	#include <asm/cputype.h>
aa024c2f	24	#include <asm/kvm_emulate.h>
4429fc64	25	#include <asm/kvm_host.h>
aa024c2f	26
221905ab MZ	27	#include <kvm/arm_psci.h>
221905ab MZ	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)
e6bc13c8 AP	35
11f4a8e7 MZ	36	static u32 smccc_get_function(struct kvm_vcpu *vcpu)
	37	{
	38	return vcpu_get_reg(vcpu, 0);
	39	}
	40
	41	static unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu)
	42	{
	43	return vcpu_get_reg(vcpu, 1);
	44	}
	45
	46	static unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu)
	47	{
	48	return vcpu_get_reg(vcpu, 2);
	49	}
	50
	51	static unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu)
	52	{
	53	return vcpu_get_reg(vcpu, 3);
	54	}
	55
	56	static void smccc_set_retval(struct kvm_vcpu *vcpu,
	57	unsigned long a0,
	58	unsigned long a1,
	59	unsigned long a2,
	60	unsigned long a3)
	61	{
	62	vcpu_set_reg(vcpu, 0, a0);
	63	vcpu_set_reg(vcpu, 1, a1);
	64	vcpu_set_reg(vcpu, 2, a2);
	65	vcpu_set_reg(vcpu, 3, a3);
	66	}
	67
e6bc13c8 AP	68	static unsigned long psci_affinity_mask(unsigned long affinity_level)
	69	{
	70	if (affinity_level <= 3)
	71	return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
	72
	73	return 0;
	74	}
	75
b376d02b AP	76	static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
	77	{
	78	/*
	79	* NOTE: For simplicity, we make VCPU suspend emulation to be
	80	* same-as WFI (Wait-for-interrupt) emulation.
	81	*
	82	* This means for KVM the wakeup events are interrupts and
	83	* this is consistent with intended use of StateID as described
	84	* in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
	85	*
	86	* Further, we also treat power-down request to be same as
	87	* stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
	88	* specification (ARM DEN 0022A). This means all suspend states
	89	* for KVM will preserve the register state.
	90	*/
	91	kvm_vcpu_block(vcpu);
6a6d73be	92	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
b376d02b AP	93
	94	return PSCI_RET_SUCCESS;
	95	}
	96
aa024c2f MZ	97	static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
aa024c2f MZ	98	{
3781528e	99	vcpu->arch.power_off = true;
7b244e2b	100	kvm_make_request(KVM_REQ_SLEEP, vcpu);
424c989b	101	kvm_vcpu_kick(vcpu);
aa024c2f MZ	102	}
	103
	104	static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
	105	{
	106	struct kvm *kvm = source_vcpu->kvm;
4429fc64	107	struct kvm_vcpu *vcpu = NULL;
8577370f	108	struct swait_queue_head *wq;
aa024c2f	109	unsigned long cpu_id;
aa8aeefe	110	unsigned long context_id;
aa024c2f MZ	111	phys_addr_t target_pc;
aa024c2f MZ	112
11f4a8e7	113	cpu_id = smccc_get_arg1(source_vcpu) & MPIDR_HWID_BITMASK;
aa024c2f MZ	114	if (vcpu_mode_is_32bit(source_vcpu))
	115	cpu_id &= ~((u32) 0);
	116
4429fc64	117	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
79c64880	118
478a8237 CD	119	/*
	120	* Make sure the caller requested a valid CPU and that the CPU is
	121	* turned off.
	122	*/
aa8aeefe	123	if (!vcpu)
7d0f84aa	124	return PSCI_RET_INVALID_PARAMS;
3781528e	125	if (!vcpu->arch.power_off) {
69b98e81	126	if (kvm_psci_version(source_vcpu, kvm) != KVM_ARM_PSCI_0_1)
aa8aeefe AP	127	return PSCI_RET_ALREADY_ON;
	128	else
	129	return PSCI_RET_INVALID_PARAMS;
	130	}
aa024c2f	131
11f4a8e7 MZ	132	target_pc = smccc_get_arg2(source_vcpu);
11f4a8e7 MZ	133	context_id = smccc_get_arg3(source_vcpu);
aa024c2f	134
aa024c2f MZ	135	kvm_reset_vcpu(vcpu);
	136
	137	/* Gracefully handle Thumb2 entry point */
	138	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
	139	target_pc &= ~((phys_addr_t) 1);
	140	vcpu_set_thumb(vcpu);
	141	}
	142
ce94fe93 MZ	143	/* Propagate caller endianness */
	144	if (kvm_vcpu_is_be(source_vcpu))
	145	kvm_vcpu_set_be(vcpu);
	146
aa024c2f	147	*vcpu_pc(vcpu) = target_pc;
aa8aeefe AP	148	/*
	149	* NOTE: We always update r0 (or x0) because for PSCI v0.1
	150	* the general puspose registers are undefined upon CPU_ON.
	151	*/
11f4a8e7	152	smccc_set_retval(vcpu, context_id, 0, 0, 0);
3781528e	153	vcpu->arch.power_off = false;
aa024c2f MZ	154	smp_mb(); /* Make sure the above is visible */
aa024c2f MZ	155
478a8237	156	wq = kvm_arch_vcpu_wq(vcpu);
8577370f	157	swake_up(wq);
aa024c2f	158
7d0f84aa	159	return PSCI_RET_SUCCESS;
aa024c2f MZ	160	}
aa024c2f MZ	161
e6bc13c8 AP	162	static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
e6bc13c8 AP	163	{
0c067292	164	int i, matching_cpus = 0;
e6bc13c8 AP	165	unsigned long mpidr;
	166	unsigned long target_affinity;
	167	unsigned long target_affinity_mask;
	168	unsigned long lowest_affinity_level;
	169	struct kvm *kvm = vcpu->kvm;
	170	struct kvm_vcpu *tmp;
	171
11f4a8e7 MZ	172	target_affinity = smccc_get_arg1(vcpu);
11f4a8e7 MZ	173	lowest_affinity_level = smccc_get_arg2(vcpu);
e6bc13c8 AP	174
	175	/* Determine target affinity mask */
	176	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
	177	if (!target_affinity_mask)
	178	return PSCI_RET_INVALID_PARAMS;
	179
	180	/* Ignore other bits of target affinity */
	181	target_affinity &= target_affinity_mask;
	182
	183	/*
	184	* If one or more VCPU matching target affinity are running
	185	* then ON else OFF
	186	*/
	187	kvm_for_each_vcpu(i, tmp, kvm) {
4429fc64	188	mpidr = kvm_vcpu_get_mpidr_aff(tmp);
0c067292 AS	189	if ((mpidr & target_affinity_mask) == target_affinity) {
0c067292 AS	190	matching_cpus++;
3781528e	191	if (!tmp->arch.power_off)
0c067292	192	return PSCI_0_2_AFFINITY_LEVEL_ON;
e6bc13c8 AP	193	}
	194	}
	195
0c067292 AS	196	if (!matching_cpus)
	197	return PSCI_RET_INVALID_PARAMS;
	198
e6bc13c8 AP	199	return PSCI_0_2_AFFINITY_LEVEL_OFF;
	200	}
	201
4b123826 AP	202	static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
4b123826 AP	203	{
cf5d3188 CD	204	int i;
	205	struct kvm_vcpu *tmp;
	206
	207	/*
	208	* The KVM ABI specifies that a system event exit may call KVM_RUN
	209	* again and may perform shutdown/reboot at a later time that when the
	210	* actual request is made. Since we are implementing PSCI and a
	211	* caller of PSCI reboot and shutdown expects that the system shuts
	212	* down or reboots immediately, let's make sure that VCPUs are not run
	213	* after this call is handled and before the VCPUs have been
	214	* re-initialized.
	215	*/
cc9b43f9	216	kvm_for_each_vcpu(i, tmp, vcpu->kvm)
3781528e	217	tmp->arch.power_off = true;
7b244e2b	218	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
cf5d3188	219
4b123826 AP	220	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	221	vcpu->run->system_event.type = type;
	222	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
	223	}
	224
	225	static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
	226	{
	227	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
	228	}
	229
	230	static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
	231	{
	232	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
	233	}
	234
e8e7fcc5	235	static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
7d0f84aa	236	{
6c7a5dce	237	struct kvm *kvm = vcpu->kvm;
11f4a8e7	238	u32 psci_fn = smccc_get_function(vcpu);
7d0f84aa	239	unsigned long val;
6c7a5dce	240	int ret = 1;
7d0f84aa AP	241
	242	switch (psci_fn) {
	243	case PSCI_0_2_FN_PSCI_VERSION:
	244	/*
	245	* Bits[31:16] = Major Version = 0
	246	* Bits[15:0] = Minor Version = 2
	247	*/
9788f802	248	val = KVM_ARM_PSCI_0_2;
7d0f84aa	249	break;
b376d02b AP	250	case PSCI_0_2_FN_CPU_SUSPEND:
	251	case PSCI_0_2_FN64_CPU_SUSPEND:
	252	val = kvm_psci_vcpu_suspend(vcpu);
	253	break;
7d0f84aa AP	254	case PSCI_0_2_FN_CPU_OFF:
	255	kvm_psci_vcpu_off(vcpu);
	256	val = PSCI_RET_SUCCESS;
	257	break;
	258	case PSCI_0_2_FN_CPU_ON:
	259	case PSCI_0_2_FN64_CPU_ON:
6c7a5dce	260	mutex_lock(&kvm->lock);
7d0f84aa	261	val = kvm_psci_vcpu_on(vcpu);
6c7a5dce	262	mutex_unlock(&kvm->lock);
7d0f84aa	263	break;
e6bc13c8 AP	264	case PSCI_0_2_FN_AFFINITY_INFO:
	265	case PSCI_0_2_FN64_AFFINITY_INFO:
	266	val = kvm_psci_vcpu_affinity_info(vcpu);
	267	break;
bab0b430 AP	268	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	269	/*
	270	* Trusted OS is MP hence does not require migration
	271	* or
	272	* Trusted OS is not present
	273	*/
	274	val = PSCI_0_2_TOS_MP;
	275	break;
4b123826 AP	276	case PSCI_0_2_FN_SYSTEM_OFF:
	277	kvm_psci_system_off(vcpu);
	278	/*
	279	* We should'nt be going back to guest VCPU after
	280	* receiving SYSTEM_OFF request.
	281	*
	282	* If user space accidently/deliberately resumes
	283	* guest VCPU after SYSTEM_OFF request then guest
	284	* VCPU should see internal failure from PSCI return
	285	* value. To achieve this, we preload r0 (or x0) with
	286	* PSCI return value INTERNAL_FAILURE.
	287	*/
	288	val = PSCI_RET_INTERNAL_FAILURE;
	289	ret = 0;
	290	break;
	291	case PSCI_0_2_FN_SYSTEM_RESET:
	292	kvm_psci_system_reset(vcpu);
	293	/*
	294	* Same reason as SYSTEM_OFF for preloading r0 (or x0)
	295	* with PSCI return value INTERNAL_FAILURE.
	296	*/
	297	val = PSCI_RET_INTERNAL_FAILURE;
	298	ret = 0;
	299	break;
7d0f84aa	300	default:
e2d99736 LP	301	val = PSCI_RET_NOT_SUPPORTED;
e2d99736 LP	302	break;
7d0f84aa AP	303	}
7d0f84aa AP	304
11f4a8e7	305	smccc_set_retval(vcpu, val, 0, 0, 0);
4b123826	306	return ret;
7d0f84aa AP	307	}
7d0f84aa AP	308
8d185513 MZ	309	static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu)
	310	{
	311	u32 psci_fn = smccc_get_function(vcpu);
	312	u32 feature;
	313	unsigned long val;
	314	int ret = 1;
	315
	316	switch(psci_fn) {
	317	case PSCI_0_2_FN_PSCI_VERSION:
	318	val = KVM_ARM_PSCI_1_0;
	319	break;
	320	case PSCI_1_0_FN_PSCI_FEATURES:
	321	feature = smccc_get_arg1(vcpu);
	322	switch(feature) {
	323	case PSCI_0_2_FN_PSCI_VERSION:
	324	case PSCI_0_2_FN_CPU_SUSPEND:
	325	case PSCI_0_2_FN64_CPU_SUSPEND:
	326	case PSCI_0_2_FN_CPU_OFF:
	327	case PSCI_0_2_FN_CPU_ON:
	328	case PSCI_0_2_FN64_CPU_ON:
	329	case PSCI_0_2_FN_AFFINITY_INFO:
	330	case PSCI_0_2_FN64_AFFINITY_INFO:
	331	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	332	case PSCI_0_2_FN_SYSTEM_OFF:
	333	case PSCI_0_2_FN_SYSTEM_RESET:
	334	case PSCI_1_0_FN_PSCI_FEATURES:
7b5b30e9	335	case ARM_SMCCC_VERSION_FUNC_ID:
8d185513 MZ	336	val = 0;
	337	break;
	338	default:
	339	val = PSCI_RET_NOT_SUPPORTED;
	340	break;
	341	}
	342	break;
	343	default:
	344	return kvm_psci_0_2_call(vcpu);
	345	}
	346
	347	smccc_set_retval(vcpu, val, 0, 0, 0);
	348	return ret;
	349	}
	350
e8e7fcc5	351	static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
aa024c2f	352	{
6c7a5dce	353	struct kvm *kvm = vcpu->kvm;
11f4a8e7	354	u32 psci_fn = smccc_get_function(vcpu);
aa024c2f MZ	355	unsigned long val;
	356
	357	switch (psci_fn) {
	358	case KVM_PSCI_FN_CPU_OFF:
	359	kvm_psci_vcpu_off(vcpu);
7d0f84aa	360	val = PSCI_RET_SUCCESS;
aa024c2f MZ	361	break;
aa024c2f MZ	362	case KVM_PSCI_FN_CPU_ON:
6c7a5dce	363	mutex_lock(&kvm->lock);
aa024c2f	364	val = kvm_psci_vcpu_on(vcpu);
6c7a5dce	365	mutex_unlock(&kvm->lock);
aa024c2f	366	break;
e2d99736	367	default:
7d0f84aa	368	val = PSCI_RET_NOT_SUPPORTED;
aa024c2f	369	break;
aa024c2f MZ	370	}
aa024c2f MZ	371
11f4a8e7	372	smccc_set_retval(vcpu, val, 0, 0, 0);
e8e7fcc5	373	return 1;
aa024c2f	374	}
7d0f84aa AP	375
	376	/**
	377	* kvm_psci_call - handle PSCI call if r0 value is in range
	378	* @vcpu: Pointer to the VCPU struct
	379	*
	380	* Handle PSCI calls from guests through traps from HVC instructions.
e8e7fcc5 AP	381	* The calling convention is similar to SMC calls to the secure world
	382	* where the function number is placed in r0.
	383	*
	384	* This function returns: > 0 (success), 0 (success but exit to user
	385	* space), and < 0 (errors)
	386	*
	387	* Errors:
	388	* -EINVAL: Unrecognized PSCI function
7d0f84aa	389	*/
7b5b30e9	390	static int kvm_psci_call(struct kvm_vcpu *vcpu)
7d0f84aa	391	{
69b98e81	392	switch (kvm_psci_version(vcpu, vcpu->kvm)) {
8d185513 MZ	393	case KVM_ARM_PSCI_1_0:
8d185513 MZ	394	return kvm_psci_1_0_call(vcpu);
7d0f84aa AP	395	case KVM_ARM_PSCI_0_2:
	396	return kvm_psci_0_2_call(vcpu);
	397	case KVM_ARM_PSCI_0_1:
	398	return kvm_psci_0_1_call(vcpu);
	399	default:
e8e7fcc5	400	return -EINVAL;
7d0f84aa AP	401	};
7d0f84aa AP	402	}
7b5b30e9 MZ	403
	404	int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
	405	{
	406	u32 func_id = smccc_get_function(vcpu);
	407	u32 val = PSCI_RET_NOT_SUPPORTED;
d5a70971	408	u32 feature;
7b5b30e9 MZ	409
	410	switch (func_id) {
	411	case ARM_SMCCC_VERSION_FUNC_ID:
	412	val = ARM_SMCCC_VERSION_1_1;
	413	break;
	414	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
d5a70971 MZ	415	feature = smccc_get_arg1(vcpu);
	416	switch(feature) {
	417	case ARM_SMCCC_ARCH_WORKAROUND_1:
	418	if (kvm_arm_harden_branch_predictor())
	419	val = 0;
	420	break;
	421	}
7b5b30e9 MZ	422	break;
	423	default:
	424	return kvm_psci_call(vcpu);
	425	}
	426
	427	smccc_set_retval(vcpu, val, 0, 0, 0);
	428	return 1;
	429	}