virt/kvm/arm/vgic/vgic-kvm-device.c - linux-imx - Git at Google

 /*
  * VGIC: KVM DEVICE API
  *
  * Copyright (C) 2015 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.
  */
 #include <linux/kvm_host.h>
 #include <kvm/arm_vgic.h>
 #include <linux/uaccess.h>
 #include <asm/kvm_mmu.h>
 #include "vgic.h"

 /* common helpers */

 int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr,
 		      phys_addr_t addr, phys_addr_t alignment)
 {
 	if (addr & ~KVM_PHYS_MASK)
 		return -E2BIG;

 	if (!IS_ALIGNED(addr, alignment))
 		return -EINVAL;

 	if (!IS_VGIC_ADDR_UNDEF(*ioaddr))
 		return -EEXIST;

 	return 0;
 }

 /**
  * kvm_vgic_addr - set or get vgic VM base addresses
  * @kvm:   pointer to the vm struct
  * @type:  the VGIC addr type, one of KVM_VGIC_V[23]_ADDR_TYPE_XXX
  * @addr:  pointer to address value
  * @write: if true set the address in the VM address space, if false read the
  *          address
  *
  * Set or get the vgic base addresses for the distributor and the virtual CPU
  * interface in the VM physical address space.  These addresses are properties
  * of the emulated core/SoC and therefore user space initially knows this
  * information.
  * Check them for sanity (alignment, double assignment). We can't check for
  * overlapping regions in case of a virtual GICv3 here, since we don't know
  * the number of VCPUs yet, so we defer this check to map_resources().
  */
 int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 {
 	int r = 0;
 	struct vgic_dist *vgic = &kvm->arch.vgic;
 	int type_needed;
 	phys_addr_t *addr_ptr, alignment;

 	mutex_lock(&kvm->lock);
 	switch (type) {
 	case KVM_VGIC_V2_ADDR_TYPE_DIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_dist_base;
 		alignment = SZ_4K;
 		break;
 	case KVM_VGIC_V2_ADDR_TYPE_CPU:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_cpu_base;
 		alignment = SZ_4K;
 		break;
 	case KVM_VGIC_V3_ADDR_TYPE_DIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_dist_base;
 		alignment = SZ_64K;
 		break;
 	case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_redist_base;
 		alignment = SZ_64K;
 		break;
 	default:
 		r = -ENODEV;
 		goto out;
 	}

 	if (vgic->vgic_model != type_needed) {
 		r = -ENODEV;
 		goto out;
 	}

 	if (write) {
 		r = vgic_check_ioaddr(kvm, addr_ptr, *addr, alignment);
 		if (!r)
 			*addr_ptr = *addr;
 	} else {
 		*addr = *addr_ptr;
 	}

 out:
 	mutex_unlock(&kvm->lock);
 	return r;
 }

 static int vgic_set_common_attr(struct kvm_device *dev,
 				struct kvm_device_attr *attr)
 {
 	int r;

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 		u64 addr;
 		unsigned long type = (unsigned long)attr->attr;

 		if (copy_from_user(&addr, uaddr, sizeof(addr)))
 			return -EFAULT;

 		r = kvm_vgic_addr(dev->kvm, type, &addr, true);
 		return (r == -ENODEV) ? -ENXIO : r;
 	}
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 		u32 val;
 		int ret = 0;

 		if (get_user(val, uaddr))
 			return -EFAULT;

 		/*
 		 * We require:
 		 * - at least 32 SPIs on top of the 16 SGIs and 16 PPIs
 		 * - at most 1024 interrupts
 		 * - a multiple of 32 interrupts
 		 */
 		if (val < (VGIC_NR_PRIVATE_IRQS + 32) ||
 		    val > VGIC_MAX_RESERVED ||
 		    (val & 31))
 			return -EINVAL;

 		mutex_lock(&dev->kvm->lock);

 		if (vgic_ready(dev->kvm) || dev->kvm->arch.vgic.nr_spis)
 			ret = -EBUSY;
 		else
 			dev->kvm->arch.vgic.nr_spis =
 				val - VGIC_NR_PRIVATE_IRQS;

 		mutex_unlock(&dev->kvm->lock);

 		return ret;
 	}
 	case KVM_DEV_ARM_VGIC_GRP_CTRL: {
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			mutex_lock(&dev->kvm->lock);
 			r = vgic_init(dev->kvm);
 			mutex_unlock(&dev->kvm->lock);
 			return r;
 		}
 		break;
 	}
 	}

 	return -ENXIO;
 }

 static int vgic_get_common_attr(struct kvm_device *dev,
 				struct kvm_device_attr *attr)
 {
 	int r = -ENXIO;

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 		u64 addr;
 		unsigned long type = (unsigned long)attr->attr;

 		r = kvm_vgic_addr(dev->kvm, type, &addr, false);
 		if (r)
 			return (r == -ENODEV) ? -ENXIO : r;

 		if (copy_to_user(uaddr, &addr, sizeof(addr)))
 			return -EFAULT;
 		break;
 	}
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;

 		r = put_user(dev->kvm->arch.vgic.nr_spis +
 			     VGIC_NR_PRIVATE_IRQS, uaddr);
 		break;
 	}
 	}

 	return r;
 }

 static int vgic_create(struct kvm_device *dev, u32 type)
 {
 	return kvm_vgic_create(dev->kvm, type);
 }

 static void vgic_destroy(struct kvm_device *dev)
 {
 	kfree(dev);
 }

 int kvm_register_vgic_device(unsigned long type)
 {
 	int ret = -ENODEV;

 	switch (type) {
 	case KVM_DEV_TYPE_ARM_VGIC_V2:
 		ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
 					      KVM_DEV_TYPE_ARM_VGIC_V2);
 		break;
 	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
 					      KVM_DEV_TYPE_ARM_VGIC_V3);

 #ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 		if (ret)
 			break;
 		ret = kvm_vgic_register_its_device();
 #endif
 		break;
 	}

 	return ret;
 }

 struct vgic_reg_attr {
 	struct kvm_vcpu *vcpu;
 	gpa_t addr;
 };

 static int parse_vgic_v2_attr(struct kvm_device *dev,
 			      struct kvm_device_attr *attr,
 			      struct vgic_reg_attr *reg_attr)
 {
 	int cpuid;

 	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
 		 KVM_DEV_ARM_VGIC_CPUID_SHIFT;

 	if (cpuid >= atomic_read(&dev->kvm->online_vcpus))
 		return -EINVAL;

 	reg_attr->vcpu = kvm_get_vcpu(dev->kvm, cpuid);
 	reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;

 	return 0;
 }

 /* unlocks vcpus from @vcpu_lock_idx and smaller */
 static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
 {
 	struct kvm_vcpu *tmp_vcpu;

 	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
 		tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
 		mutex_unlock(&tmp_vcpu->mutex);
 	}
 }

 static void unlock_all_vcpus(struct kvm *kvm)
 {
 	unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
 }

 /* Returns true if all vcpus were locked, false otherwise */
 static bool lock_all_vcpus(struct kvm *kvm)
 {
 	struct kvm_vcpu *tmp_vcpu;
 	int c;

 	/*
 	 * Any time a vcpu is run, vcpu_load is called which tries to grab the
 	 * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
 	 * that no other VCPUs are run and fiddle with the vgic state while we
 	 * access it.
 	 */
 	kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
 		if (!mutex_trylock(&tmp_vcpu->mutex)) {
 			unlock_vcpus(kvm, c - 1);
 			return false;
 		}
 	}

 	return true;
 }

 /**
  * vgic_attr_regs_access_v2 - allows user space to access VGIC v2 state
  *
  * @dev:      kvm device handle
  * @attr:     kvm device attribute
  * @reg:      address the value is read or written
  * @is_write: true if userspace is writing a register
  */
 static int vgic_attr_regs_access_v2(struct kvm_device *dev,
 				    struct kvm_device_attr *attr,
 				    u32 *reg, bool is_write)
 {
 	struct vgic_reg_attr reg_attr;
 	gpa_t addr;
 	struct kvm_vcpu *vcpu;
 	int ret;

 	ret = parse_vgic_v2_attr(dev, attr, &reg_attr);
 	if (ret)
 		return ret;

 	vcpu = reg_attr.vcpu;
 	addr = reg_attr.addr;

 	mutex_lock(&dev->kvm->lock);

 	ret = vgic_init(dev->kvm);
 	if (ret)
 		goto out;

 	if (!lock_all_vcpus(dev->kvm)) {
 		ret = -EBUSY;
 		goto out;
 	}

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	unlock_all_vcpus(dev->kvm);
 out:
 	mutex_unlock(&dev->kvm->lock);
 	return ret;
 }

 static int vgic_v2_set_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	int ret;

 	ret = vgic_set_common_attr(dev, attr);
 	if (ret != -ENXIO)
 		return ret;

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 		u32 reg;

 		if (get_user(reg, uaddr))
 			return -EFAULT;

 		return vgic_attr_regs_access_v2(dev, attr, &reg, true);
 	}
 	}

 	return -ENXIO;
 }

 static int vgic_v2_get_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	int ret;

 	ret = vgic_get_common_attr(dev, attr);
 	if (ret != -ENXIO)
 		return ret;

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 		u32 reg = 0;

 		ret = vgic_attr_regs_access_v2(dev, attr, &reg, false);
 		if (ret)
 			return ret;
 		return put_user(reg, uaddr);
 	}
 	}

 	return -ENXIO;
 }

 static int vgic_v2_has_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_ADDR:
 		switch (attr->attr) {
 		case KVM_VGIC_V2_ADDR_TYPE_DIST:
 		case KVM_VGIC_V2_ADDR_TYPE_CPU:
 			return 0;
 		}
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 		return vgic_v2_has_attr_regs(dev, attr);
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 		return 0;
 	case KVM_DEV_ARM_VGIC_GRP_CTRL:
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return 0;
 		}
 	}
 	return -ENXIO;
 }

 struct kvm_device_ops kvm_arm_vgic_v2_ops = {
 	.name = "kvm-arm-vgic-v2",
 	.create = vgic_create,
 	.destroy = vgic_destroy,
 	.set_attr = vgic_v2_set_attr,
 	.get_attr = vgic_v2_get_attr,
 	.has_attr = vgic_v2_has_attr,
 };

 static int vgic_v3_set_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	return vgic_set_common_attr(dev, attr);
 }

 static int vgic_v3_get_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	return vgic_get_common_attr(dev, attr);
 }

 static int vgic_v3_has_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_ADDR:
 		switch (attr->attr) {
 		case KVM_VGIC_V3_ADDR_TYPE_DIST:
 		case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 			return 0;
 		}
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 		return 0;
 	case KVM_DEV_ARM_VGIC_GRP_CTRL:
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return 0;
 		}
 	}
 	return -ENXIO;
 }

 struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 	.name = "kvm-arm-vgic-v3",
 	.create = vgic_create,
 	.destroy = vgic_destroy,
 	.set_attr = vgic_v3_set_attr,
 	.get_attr = vgic_v3_get_attr,
 	.has_attr = vgic_v3_has_attr,
 };
	/*
	* VGIC: KVM DEVICE API
	*
	* Copyright (C) 2015 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.
	*/
	#include <linux/kvm_host.h>
	#include <kvm/arm_vgic.h>
	#include <linux/uaccess.h>
	#include <asm/kvm_mmu.h>
	#include "vgic.h"

	/* common helpers */

	int vgic_check_ioaddr(struct kvm kvm, phys_addr_t ioaddr,
	phys_addr_t addr, phys_addr_t alignment)
	{
	if (addr & ~KVM_PHYS_MASK)
	return -E2BIG;

	if (!IS_ALIGNED(addr, alignment))
	return -EINVAL;

	if (!IS_VGIC_ADDR_UNDEF(*ioaddr))
	return -EEXIST;

	return 0;
	}

	/**
	* kvm_vgic_addr - set or get vgic VM base addresses
	* @kvm: pointer to the vm struct
	* @type: the VGIC addr type, one of KVM_VGIC_V[23]_ADDR_TYPE_XXX
	* @addr: pointer to address value
	* @write: if true set the address in the VM address space, if false read the
	* address
	*
	* Set or get the vgic base addresses for the distributor and the virtual CPU
	* interface in the VM physical address space. These addresses are properties
	* of the emulated core/SoC and therefore user space initially knows this
	* information.
	* Check them for sanity (alignment, double assignment). We can't check for
	* overlapping regions in case of a virtual GICv3 here, since we don't know
	* the number of VCPUs yet, so we defer this check to map_resources().
	*/
	int kvm_vgic_addr(struct kvm kvm, unsigned long type, u64 addr, bool write)
	{
	int r = 0;
	struct vgic_dist *vgic = &kvm->arch.vgic;
	int type_needed;
	phys_addr_t *addr_ptr, alignment;

	mutex_lock(&kvm->lock);
	switch (type) {
	case KVM_VGIC_V2_ADDR_TYPE_DIST:
	type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
	addr_ptr = &vgic->vgic_dist_base;
	alignment = SZ_4K;
	break;
	case KVM_VGIC_V2_ADDR_TYPE_CPU:
	type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
	addr_ptr = &vgic->vgic_cpu_base;
	alignment = SZ_4K;
	break;
	case KVM_VGIC_V3_ADDR_TYPE_DIST:
	type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
	addr_ptr = &vgic->vgic_dist_base;
	alignment = SZ_64K;
	break;
	case KVM_VGIC_V3_ADDR_TYPE_REDIST:
	type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
	addr_ptr = &vgic->vgic_redist_base;
	alignment = SZ_64K;
	break;
	default:
	r = -ENODEV;
	goto out;
	}

	if (vgic->vgic_model != type_needed) {
	r = -ENODEV;
	goto out;
	}

	if (write) {
	r = vgic_check_ioaddr(kvm, addr_ptr, *addr, alignment);
	if (!r)
	addr_ptr = addr;
	} else {
	addr = addr_ptr;
	}

	out:
	mutex_unlock(&kvm->lock);
	return r;
	}

	static int vgic_set_common_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	int r;

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
	u64 __user uaddr = (u64 __user )(long)attr->addr;
	u64 addr;
	unsigned long type = (unsigned long)attr->attr;

	if (copy_from_user(&addr, uaddr, sizeof(addr)))
	return -EFAULT;

	r = kvm_vgic_addr(dev->kvm, type, &addr, true);
	return (r == -ENODEV) ? -ENXIO : r;
	}
	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
	u32 __user uaddr = (u32 __user )(long)attr->addr;
	u32 val;
	int ret = 0;

	if (get_user(val, uaddr))
	return -EFAULT;

	/*
	* We require:
	* - at least 32 SPIs on top of the 16 SGIs and 16 PPIs
	* - at most 1024 interrupts
	* - a multiple of 32 interrupts
	*/
	if (val < (VGIC_NR_PRIVATE_IRQS + 32) \|\|
	val > VGIC_MAX_RESERVED \|\|
	(val & 31))
	return -EINVAL;

	mutex_lock(&dev->kvm->lock);

	if (vgic_ready(dev->kvm) \|\| dev->kvm->arch.vgic.nr_spis)
	ret = -EBUSY;
	else
	dev->kvm->arch.vgic.nr_spis =
	val - VGIC_NR_PRIVATE_IRQS;

	mutex_unlock(&dev->kvm->lock);

	return ret;
	}
	case KVM_DEV_ARM_VGIC_GRP_CTRL: {
	switch (attr->attr) {
	case KVM_DEV_ARM_VGIC_CTRL_INIT:
	mutex_lock(&dev->kvm->lock);
	r = vgic_init(dev->kvm);
	mutex_unlock(&dev->kvm->lock);
	return r;
	}
	break;
	}
	}

	return -ENXIO;
	}

	static int vgic_get_common_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	int r = -ENXIO;

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
	u64 __user uaddr = (u64 __user )(long)attr->addr;
	u64 addr;
	unsigned long type = (unsigned long)attr->attr;

	r = kvm_vgic_addr(dev->kvm, type, &addr, false);
	if (r)
	return (r == -ENODEV) ? -ENXIO : r;

	if (copy_to_user(uaddr, &addr, sizeof(addr)))
	return -EFAULT;
	break;
	}
	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
	u32 __user uaddr = (u32 __user )(long)attr->addr;

	r = put_user(dev->kvm->arch.vgic.nr_spis +
	VGIC_NR_PRIVATE_IRQS, uaddr);
	break;
	}
	}

	return r;
	}

	static int vgic_create(struct kvm_device *dev, u32 type)
	{
	return kvm_vgic_create(dev->kvm, type);
	}

	static void vgic_destroy(struct kvm_device *dev)
	{
	kfree(dev);
	}

	int kvm_register_vgic_device(unsigned long type)
	{
	int ret = -ENODEV;

	switch (type) {
	case KVM_DEV_TYPE_ARM_VGIC_V2:
	ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
	KVM_DEV_TYPE_ARM_VGIC_V2);
	break;
	case KVM_DEV_TYPE_ARM_VGIC_V3:
	ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
	KVM_DEV_TYPE_ARM_VGIC_V3);

	#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
	if (ret)
	break;
	ret = kvm_vgic_register_its_device();
	#endif
	break;
	}

	return ret;
	}

	struct vgic_reg_attr {
	struct kvm_vcpu *vcpu;
	gpa_t addr;
	};

	static int parse_vgic_v2_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr,
	struct vgic_reg_attr *reg_attr)
	{
	int cpuid;

	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
	KVM_DEV_ARM_VGIC_CPUID_SHIFT;

	if (cpuid >= atomic_read(&dev->kvm->online_vcpus))
	return -EINVAL;

	reg_attr->vcpu = kvm_get_vcpu(dev->kvm, cpuid);
	reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;

	return 0;
	}

	/* unlocks vcpus from @vcpu_lock_idx and smaller */
	static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
	{
	struct kvm_vcpu *tmp_vcpu;

	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
	tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
	mutex_unlock(&tmp_vcpu->mutex);
	}
	}

	static void unlock_all_vcpus(struct kvm *kvm)
	{
	unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
	}

	/* Returns true if all vcpus were locked, false otherwise */
	static bool lock_all_vcpus(struct kvm *kvm)
	{
	struct kvm_vcpu *tmp_vcpu;
	int c;

	/*
	* Any time a vcpu is run, vcpu_load is called which tries to grab the
	* vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
	* that no other VCPUs are run and fiddle with the vgic state while we
	* access it.
	*/
	kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
	if (!mutex_trylock(&tmp_vcpu->mutex)) {
	unlock_vcpus(kvm, c - 1);
	return false;
	}
	}

	return true;
	}

	/**
	* vgic_attr_regs_access_v2 - allows user space to access VGIC v2 state
	*
	* @dev: kvm device handle
	* @attr: kvm device attribute
	* @reg: address the value is read or written
	* @is_write: true if userspace is writing a register
	*/
	static int vgic_attr_regs_access_v2(struct kvm_device *dev,
	struct kvm_device_attr *attr,
	u32 *reg, bool is_write)
	{
	struct vgic_reg_attr reg_attr;
	gpa_t addr;
	struct kvm_vcpu *vcpu;
	int ret;

	ret = parse_vgic_v2_attr(dev, attr, &reg_attr);
	if (ret)
	return ret;

	vcpu = reg_attr.vcpu;
	addr = reg_attr.addr;

	mutex_lock(&dev->kvm->lock);

	ret = vgic_init(dev->kvm);
	if (ret)
	goto out;

	if (!lock_all_vcpus(dev->kvm)) {
	ret = -EBUSY;
	goto out;
	}

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
	ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
	break;
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
	ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
	break;
	default:
	ret = -EINVAL;
	break;
	}

	unlock_all_vcpus(dev->kvm);
	out:
	mutex_unlock(&dev->kvm->lock);
	return ret;
	}

	static int vgic_v2_set_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	int ret;

	ret = vgic_set_common_attr(dev, attr);
	if (ret != -ENXIO)
	return ret;

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
	u32 __user uaddr = (u32 __user )(long)attr->addr;
	u32 reg;

	if (get_user(reg, uaddr))
	return -EFAULT;

	return vgic_attr_regs_access_v2(dev, attr, &reg, true);
	}
	}

	return -ENXIO;
	}

	static int vgic_v2_get_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	int ret;

	ret = vgic_get_common_attr(dev, attr);
	if (ret != -ENXIO)
	return ret;

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
	u32 __user uaddr = (u32 __user )(long)attr->addr;
	u32 reg = 0;

	ret = vgic_attr_regs_access_v2(dev, attr, &reg, false);
	if (ret)
	return ret;
	return put_user(reg, uaddr);
	}
	}

	return -ENXIO;
	}

	static int vgic_v2_has_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_ADDR:
	switch (attr->attr) {
	case KVM_VGIC_V2_ADDR_TYPE_DIST:
	case KVM_VGIC_V2_ADDR_TYPE_CPU:
	return 0;
	}
	break;
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
	return vgic_v2_has_attr_regs(dev, attr);
	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
	return 0;
	case KVM_DEV_ARM_VGIC_GRP_CTRL:
	switch (attr->attr) {
	case KVM_DEV_ARM_VGIC_CTRL_INIT:
	return 0;
	}
	}
	return -ENXIO;
	}

	struct kvm_device_ops kvm_arm_vgic_v2_ops = {
	.name = "kvm-arm-vgic-v2",
	.create = vgic_create,
	.destroy = vgic_destroy,
	.set_attr = vgic_v2_set_attr,
	.get_attr = vgic_v2_get_attr,
	.has_attr = vgic_v2_has_attr,
	};

	static int vgic_v3_set_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	return vgic_set_common_attr(dev, attr);
	}

	static int vgic_v3_get_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	return vgic_get_common_attr(dev, attr);
	}

	static int vgic_v3_has_attr(struct kvm_device *dev,
	struct kvm_device_attr *attr)
	{
	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_ADDR:
	switch (attr->attr) {
	case KVM_VGIC_V3_ADDR_TYPE_DIST:
	case KVM_VGIC_V3_ADDR_TYPE_REDIST:
	return 0;
	}
	break;
	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
	return 0;
	case KVM_DEV_ARM_VGIC_GRP_CTRL:
	switch (attr->attr) {
	case KVM_DEV_ARM_VGIC_CTRL_INIT:
	return 0;
	}
	}
	return -ENXIO;
	}

	struct kvm_device_ops kvm_arm_vgic_v3_ops = {
	.name = "kvm-arm-vgic-v3",
	.create = vgic_create,
	.destroy = vgic_destroy,
	.set_attr = vgic_v3_set_attr,
	.get_attr = vgic_v3_get_attr,
	.has_attr = vgic_v3_has_attr,
	};