[linux-2.6-block.git] / arch / arm / kvm / 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/kvm_host.h>
#include <linux/wait.h>

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

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

static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
{
	vcpu->arch.pause = true;
}

static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
	struct kvm *kvm = source_vcpu->kvm;
	struct kvm_vcpu *vcpu = NULL, *tmp;
	wait_queue_head_t *wq;
	unsigned long cpu_id;
	unsigned long mpidr;
	phys_addr_t target_pc;
	int i;

	cpu_id = *vcpu_reg(source_vcpu, 1);
	if (vcpu_mode_is_32bit(source_vcpu))
		cpu_id &= ~((u32) 0);

	kvm_for_each_vcpu(i, tmp, kvm) {
		mpidr = kvm_vcpu_get_mpidr(tmp);
		if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
			vcpu = tmp;
			break;
		}
	}

	/*
	 * Make sure the caller requested a valid CPU and that the CPU is
	 * turned off.
	 */
	if (!vcpu || !vcpu->arch.pause)
		return PSCI_RET_INVALID_PARAMS;

	target_pc = *vcpu_reg(source_vcpu, 2);

	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;
	vcpu->arch.pause = false;
	smp_mb();		/* Make sure the above is visible */

	wq = kvm_arch_vcpu_wq(vcpu);
	wake_up_interruptible(wq);

	return PSCI_RET_SUCCESS;
}

static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
{
	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)
{
	int ret = 1;
	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	unsigned long val;

	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_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:
		val = kvm_psci_vcpu_on(vcpu);
		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;
	case PSCI_0_2_FN_CPU_SUSPEND:
	case PSCI_0_2_FN_AFFINITY_INFO:
	case PSCI_0_2_FN_MIGRATE:
	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
	case PSCI_0_2_FN64_CPU_SUSPEND:
	case PSCI_0_2_FN64_AFFINITY_INFO:
	case PSCI_0_2_FN64_MIGRATE:
	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	default:
		return -EINVAL;
	}

	*vcpu_reg(vcpu, 0) = val;
	return ret;
}

static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
	unsigned long psci_fn = *vcpu_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:
		val = kvm_psci_vcpu_on(vcpu);
		break;
	case KVM_PSCI_FN_CPU_SUSPEND:
	case KVM_PSCI_FN_MIGRATE:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	default:
		return -EINVAL;
	}

	*vcpu_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
	18	#include <linux/kvm_host.h>
	19	#include <linux/wait.h>
	20
79c64880	21	#include <asm/cputype.h>
aa024c2f MZ	22	#include <asm/kvm_emulate.h>
	23	#include <asm/kvm_psci.h>
	24
	25	/*
	26	* This is an implementation of the Power State Coordination Interface
	27	* as described in ARM document number ARM DEN 0022A.
	28	*/
	29
	30	static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
	31	{
	32	vcpu->arch.pause = true;
	33	}
	34
	35	static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
	36	{
	37	struct kvm *kvm = source_vcpu->kvm;
79c64880	38	struct kvm_vcpu vcpu = NULL, tmp;
aa024c2f MZ	39	wait_queue_head_t *wq;
aa024c2f MZ	40	unsigned long cpu_id;
79c64880	41	unsigned long mpidr;
aa024c2f	42	phys_addr_t target_pc;
79c64880	43	int i;
aa024c2f MZ	44
	45	cpu_id = *vcpu_reg(source_vcpu, 1);
	46	if (vcpu_mode_is_32bit(source_vcpu))
	47	cpu_id &= ~((u32) 0);
	48
79c64880 MZ	49	kvm_for_each_vcpu(i, tmp, kvm) {
	50	mpidr = kvm_vcpu_get_mpidr(tmp);
	51	if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
	52	vcpu = tmp;
	53	break;
	54	}
	55	}
	56
478a8237 CD	57	/*
	58	* Make sure the caller requested a valid CPU and that the CPU is
	59	* turned off.
	60	*/
	61	if (!vcpu \|\| !vcpu->arch.pause)
7d0f84aa	62	return PSCI_RET_INVALID_PARAMS;
aa024c2f MZ	63
	64	target_pc = *vcpu_reg(source_vcpu, 2);
	65
aa024c2f MZ	66	kvm_reset_vcpu(vcpu);
	67
	68	/* Gracefully handle Thumb2 entry point */
	69	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
	70	target_pc &= ~((phys_addr_t) 1);
	71	vcpu_set_thumb(vcpu);
	72	}
	73
ce94fe93 MZ	74	/* Propagate caller endianness */
	75	if (kvm_vcpu_is_be(source_vcpu))
	76	kvm_vcpu_set_be(vcpu);
	77
aa024c2f MZ	78	*vcpu_pc(vcpu) = target_pc;
	79	vcpu->arch.pause = false;
	80	smp_mb(); /* Make sure the above is visible */
	81
478a8237	82	wq = kvm_arch_vcpu_wq(vcpu);
aa024c2f MZ	83	wake_up_interruptible(wq);
aa024c2f MZ	84
7d0f84aa	85	return PSCI_RET_SUCCESS;
aa024c2f MZ	86	}
aa024c2f MZ	87
4b123826 AP	88	static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
	89	{
	90	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	91	vcpu->run->system_event.type = type;
	92	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
	93	}
	94
	95	static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
	96	{
	97	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
	98	}
	99
	100	static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
	101	{
	102	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
	103	}
	104
7d0f84aa AP	105	int kvm_psci_version(struct kvm_vcpu *vcpu)
	106	{
	107	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
	108	return KVM_ARM_PSCI_0_2;
	109
	110	return KVM_ARM_PSCI_0_1;
	111	}
	112
e8e7fcc5	113	static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
7d0f84aa	114	{
4b123826	115	int ret = 1;
7d0f84aa AP	116	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	117	unsigned long val;
	118
	119	switch (psci_fn) {
	120	case PSCI_0_2_FN_PSCI_VERSION:
	121	/*
	122	* Bits[31:16] = Major Version = 0
	123	* Bits[15:0] = Minor Version = 2
	124	*/
	125	val = 2;
	126	break;
	127	case PSCI_0_2_FN_CPU_OFF:
	128	kvm_psci_vcpu_off(vcpu);
	129	val = PSCI_RET_SUCCESS;
	130	break;
	131	case PSCI_0_2_FN_CPU_ON:
	132	case PSCI_0_2_FN64_CPU_ON:
	133	val = kvm_psci_vcpu_on(vcpu);
	134	break;
4b123826 AP	135	case PSCI_0_2_FN_SYSTEM_OFF:
	136	kvm_psci_system_off(vcpu);
	137	/*
	138	* We should'nt be going back to guest VCPU after
	139	* receiving SYSTEM_OFF request.
	140	*
	141	* If user space accidently/deliberately resumes
	142	* guest VCPU after SYSTEM_OFF request then guest
	143	* VCPU should see internal failure from PSCI return
	144	* value. To achieve this, we preload r0 (or x0) with
	145	* PSCI return value INTERNAL_FAILURE.
	146	*/
	147	val = PSCI_RET_INTERNAL_FAILURE;
	148	ret = 0;
	149	break;
	150	case PSCI_0_2_FN_SYSTEM_RESET:
	151	kvm_psci_system_reset(vcpu);
	152	/*
	153	* Same reason as SYSTEM_OFF for preloading r0 (or x0)
	154	* with PSCI return value INTERNAL_FAILURE.
	155	*/
	156	val = PSCI_RET_INTERNAL_FAILURE;
	157	ret = 0;
	158	break;
7d0f84aa AP	159	case PSCI_0_2_FN_CPU_SUSPEND:
	160	case PSCI_0_2_FN_AFFINITY_INFO:
	161	case PSCI_0_2_FN_MIGRATE:
	162	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	163	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
7d0f84aa AP	164	case PSCI_0_2_FN64_CPU_SUSPEND:
	165	case PSCI_0_2_FN64_AFFINITY_INFO:
	166	case PSCI_0_2_FN64_MIGRATE:
	167	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
	168	val = PSCI_RET_NOT_SUPPORTED;
	169	break;
	170	default:
e8e7fcc5	171	return -EINVAL;
7d0f84aa AP	172	}
	173
	174	*vcpu_reg(vcpu, 0) = val;
4b123826	175	return ret;
7d0f84aa AP	176	}
7d0f84aa AP	177
e8e7fcc5	178	static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
aa024c2f MZ	179	{
	180	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	181	unsigned long val;
	182
	183	switch (psci_fn) {
	184	case KVM_PSCI_FN_CPU_OFF:
	185	kvm_psci_vcpu_off(vcpu);
7d0f84aa	186	val = PSCI_RET_SUCCESS;
aa024c2f MZ	187	break;
	188	case KVM_PSCI_FN_CPU_ON:
	189	val = kvm_psci_vcpu_on(vcpu);
	190	break;
	191	case KVM_PSCI_FN_CPU_SUSPEND:
	192	case KVM_PSCI_FN_MIGRATE:
7d0f84aa	193	val = PSCI_RET_NOT_SUPPORTED;
aa024c2f	194	break;
aa024c2f	195	default:
e8e7fcc5	196	return -EINVAL;
aa024c2f MZ	197	}
	198
	199	*vcpu_reg(vcpu, 0) = val;
e8e7fcc5	200	return 1;
aa024c2f	201	}
7d0f84aa AP	202
	203	/**
	204	* kvm_psci_call - handle PSCI call if r0 value is in range
	205	* @vcpu: Pointer to the VCPU struct
	206	*
	207	* Handle PSCI calls from guests through traps from HVC instructions.
e8e7fcc5 AP	208	* The calling convention is similar to SMC calls to the secure world
	209	* where the function number is placed in r0.
	210	*
	211	* This function returns: > 0 (success), 0 (success but exit to user
	212	* space), and < 0 (errors)
	213	*
	214	* Errors:
	215	* -EINVAL: Unrecognized PSCI function
7d0f84aa	216	*/
e8e7fcc5	217	int kvm_psci_call(struct kvm_vcpu *vcpu)
7d0f84aa AP	218	{
	219	switch (kvm_psci_version(vcpu)) {
	220	case KVM_ARM_PSCI_0_2:
	221	return kvm_psci_0_2_call(vcpu);
	222	case KVM_ARM_PSCI_0_1:
	223	return kvm_psci_0_1_call(vcpu);
	224	default:
e8e7fcc5	225	return -EINVAL;
7d0f84aa AP	226	};
7d0f84aa AP	227	}