path: root/virt/kvm/arm/vgic-v2-emul.c

/*
 * Contains GICv2 specific emulation code, was in vgic.c before.
 *
 * 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/cpu.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <linux/irqchip/arm-gic.h>

#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>

#include "vgic.h"

#define GICC_ARCH_VERSION_V2		0x2

static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi)
{
	return dist->irq_sgi_sources + vcpu_id * VGIC_NR_SGIS + sgi;
}

static bool handle_mmio_misc(struct kvm_vcpu *vcpu,
			     struct kvm_exit_mmio *mmio, phys_addr_t offset)
{
	u32 reg;
	u32 word_offset = offset & 3;

	switch (offset & ~3) {
	case 0:			/* GICD_CTLR */
		reg = vcpu->kvm->arch.vgic.enabled;
		vgic_reg_access(mmio, &reg, word_offset,
				ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
		if (mmio->is_write) {
			vcpu->kvm->arch.vgic.enabled = reg & 1;
			vgic_update_state(vcpu->kvm);
			return true;
		}
		break;

	case 4:			/* GICD_TYPER */
		reg  = (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
		reg |= (vcpu->kvm->arch.vgic.nr_irqs >> 5) - 1;
		vgic_reg_access(mmio, &reg, word_offset,
				ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
		break;

	case 8:			/* GICD_IIDR */
		reg = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
		vgic_reg_access(mmio, &reg, word_offset,
				ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
		break;
	}

	return false;
}

static bool handle_mmio_set_enable_reg(struct kvm_vcpu *vcpu,
				       struct kvm_exit_mmio *mmio,
				       phys_addr_t offset)
{
	return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
				      vcpu->vcpu_id, ACCESS_WRITE_SETBIT);
}

static bool handle_mmio_clear_enable_reg(struct kvm_vcpu *vcpu,
					 struct kvm_exit_mmio *mmio,
					 phys_addr_t offset)
{
	return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
				      vcpu->vcpu_id, ACCESS_WRITE_CLEARBIT);
}

static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
					struct kvm_exit_mmio *mmio,
					phys_addr_t offset)
{
	return vgic_handle_set_pending_reg(vcpu->kvm, mmio, offset,
					   vcpu->vcpu_id);
}

static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
					  struct kvm_exit_mmio *mmio,
					  phys_addr_t offset)
{
	return vgic_handle_clear_pending_reg(vcpu->kvm, mmio, offset,
					     vcpu->vcpu_id);
}

static bool handle_mmio_set_active_reg(struct kvm_vcpu *vcpu,
				       struct kvm_exit_mmio *mmio,
				       phys_addr_t offset)
{
	return vgic_handle_set_active_reg(vcpu->kvm, mmio, offset,
					  vcpu->vcpu_id);
}

static bool handle_mmio_clear_active_reg(struct kvm_vcpu *vcpu,
					 struct kvm_exit_mmio *mmio,
					 phys_addr_t offset)
{
	return vgic_handle_clear_active_reg(vcpu->kvm, mmio, offset,
					    vcpu->vcpu_id);
}

static bool handle_mmio_priority_reg(struct kvm_vcpu *vcpu,
				     struct kvm_exit_mmio *mmio,
				     phys_addr_t offset)
{
	u32 *reg = vgic_bytemap_get_reg(&vcpu->kvm->arch.vgic.irq_priority,
					vcpu->vcpu_id, offset);
	vgic_reg_access(mmio, reg, offset,
			ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
	return false;
}

#define GICD_ITARGETSR_SIZE	32
#define GICD_CPUTARGETS_BITS	8
#define GICD_IRQS_PER_ITARGETSR	(GICD_ITARGETSR_SIZE / GICD_CPUTARGETS_BITS)
static u32 vgic_get_target_reg(struct kvm *kvm, int irq)
{
	struct vgic_dist *dist = &kvm->arch.vgic;
	int i;
	u32 val = 0;

	irq -= VGIC_NR_PRIVATE_IRQS;

	for (i = 0; i < GICD_IRQS_PER_ITARGETSR; i++)
		val |= 1 << (dist->irq_spi_cpu[irq + i] + i * 8);

	return val;
}

static void vgic_set_target_reg(struct kvm *kvm, u32 val, int irq)
{
	struct vgic_dist *dist = &kvm->arch.vgic;
	struct kvm_vcpu *vcpu;
	int i, c;
	unsigned long *bmap;
	u32 target;

	irq -= VGIC_NR_PRIVATE_IRQS;

	/*
	 * Pick the LSB in each byte. This ensures we target exactly
	 * one vcpu per IRQ. If the byte is null, assume we target
	 * CPU0.
	 */
	for (i = 0; i < GICD_IRQS_PER_ITARGETSR; i++) {
		int shift = i * GICD_CPUTARGETS_BITS;

		target = ffs((val >> shift) & 0xffU);
		target = target ? (target - 1) : 0;
		dist->irq_spi_cpu[irq + i] = target;
		kvm_for_each_vcpu(c, vcpu, kvm) {
			bmap = vgic_bitmap_get_shared_map(&dist->irq_spi_target[c]);
			if (c == target)
				set_bit(irq + i, bmap);
			else
				clear_bit(irq + i, bmap);
		}
	}
}

static bool handle_mmio_target_reg(struct kvm_vcpu *vcpu,
				   struct kvm_exit_mmio *mmio,
				   phys_addr_t offset)
{
	u32 reg;

	/* We treat the banked interrupts targets as read-only */
	if (offset < 32) {
		u32 roreg;

		roreg = 1 << vcpu->vcpu_id;
		roreg |= roreg << 8;
		roreg |= roreg << 16;

		vgic_reg_access(mmio, &roreg, offset,
				ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
		return false;
	}

	reg = vgic_get_target_reg(vcpu->kvm, offset & ~3U);
	vgic_reg_access(mmio, &reg, offset,
			ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
	if (mmio->is_write) {
		vgic_set_target_reg(vcpu->kvm, reg, offset & ~3U);
		vgic_update_state(vcpu->kvm);
		return true;
	}

	return false;
}

static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
				struct kvm_exit_mmio *mmio, phys_addr_t offset)
{
	u32 *reg;

	reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
				  vcpu->vcpu_id, offset >> 1);

	return vgic_handle_cfg_reg(reg, mmio, offset);
}

static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu,
				struct kvm_exit_mmio *mmio, phys_addr_t offset)
{
	u32 reg;

	vgic_reg_access(mmio, &reg, offset,
			ACCESS_READ_RAZ | ACCESS_WRITE_VALUE);
	if (mmio->is_write) {
		vgic_dispatch_sgi(vcpu, reg);
		vgic_update_state(vcpu->kvm);
		return true;
	}

	return false;
}

/* Handle reads of GICD_CPENDSGIRn and GICD_SPENDSGIRn */
static bool read_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
					struct kvm_exit_mmio *mmio,
					phys_addr_t offset)
{
	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
	int sgi;
	int min_sgi = (offset & ~0x3);
	int max_sgi = min_sgi + 3;
	int vcpu_id = vcpu->vcpu_id;
	u32 reg = 0;

	/* Copy source SGIs from distributor side */
	for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
		u8 sources = *vgic_get_sgi_sources(dist, vcpu_id, sgi);

		reg |= ((u32)sources) << (8 * (sgi - min_sgi));
	}

	mmio_data_write(mmio, ~0, reg);
	return false;
}

static bool write_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
					 struct kvm_exit_mmio *mmio,
					 phys_addr_t offset, bool set)
{
	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
	int sgi;
	int min_sgi = (offset & ~0x3);
	int max_sgi = min_sgi + 3;
	int vcpu_id = vcpu->vcpu_id;
	u32 reg;
	bool updated = false;

	reg = mmio_data_read(mmio, ~0);

	/* Clear pending SGIs on the distributor */
	for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
		u8 mask = reg >> (8 * (sgi - min_sgi));
		u8 *src = vgic_get_sgi_sources(dist, vcpu_id, sgi);

		if (set) {
			if ((*src & mask) != mask)
				updated = true;
			*src |= mask;
		} else {
			if (*src & mask)
				updated = true;
			*src &= ~mask;
		}
	}

	if (updated)
		vgic_update_state(vcpu->kvm);

	return updated;
}

static bool handle_mmio_sgi_set(struct kvm_vcpu *vcpu,
				struct kvm_exit_mmio *mmio,
				phys_addr_t offset)
{
	if (!mmio->is_write)
		return read_set_clear_sgi_pend_reg(vcpu, mmio, offset);
	else
		return write_set_clear_sgi_pend_reg(vcpu, mmio, offset, true);
}

static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu,
				  struct kvm_exit_mmio *mmio,
				  phys_addr_t offset)
{
	if (!mmio->is_write)
		return read_set_clear_sgi_pend_reg(vcpu, mmio, offset);
	else
		return write_set_clear_sgi_pend_reg(vcpu, mmio, offset, false);
}

static const struct vgic_io_range vgic_dist_ranges[] = {
	{
		.base		= GIC_DIST_CTRL,
		.len		= 12,
		.bits_per_irq	= 0,
		.handle_mmio	= handle_mmio_misc,
	},
	{
		.base		= GIC_DIST_IGROUP,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_raz_wi,
	},
	{
		.base		= GIC_DIST_ENABLE_SET,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_set_enable_reg,
	},
	{
		.base		= GIC_DIST_ENABLE_CLEAR,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_clear_enable_reg,
	},
	{
		.base		= GIC_DIST_PENDING_SET,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_set_pending_reg,
	},
	{
		.base		= GIC_DIST_PENDING_CLEAR,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_clear_pending_reg,
	},
	{
		.base		= GIC_DIST_ACTIVE_SET,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_set_active_reg,
	},
	{
		.base		= GIC_DIST_ACTIVE_CLEAR,
		.len		= VGIC_MAX_IRQS / 8,
		.bits_per_irq	= 1,
		.handle_mmio	= handle_mmio_clear_active_reg,
	},
	{
		.base		= GIC_DIST_PRI,
		.len		= VGIC_MAX_IRQS,
		.bits_per_irq	= 8,
		.handle_mmio	= handle_mmio_priority_reg,
	},
	{
		.base		= GIC_DIST_TARGET,
		.len		= VGIC_MAX_IRQS,
		.bits_per_irq	= 8,
		.handle_mmio	= handle_mmio_target_reg,
	},
	{
		.base		= GIC_DIST_CONFIG,
		.len		= VGIC_MAX_IRQS / 4,
		.bits_per_irq	= 2,
		.handle_mmio	= handle_mmio_cfg_reg,
	},
	{
		.base		= GIC_DIST_SOFTINT,
		.len		= 4,
		.handle_mmio	= handle_mmio_sgi_reg,
	},
	{
		.base		= GIC_DIST_SGI_PENDING_CLEAR,
		.len		= VGIC_NR_SGIS,
		.handle_mmio	= handle_mmio_sgi_clear,
	},
	{
		.base		= GIC_DIST_SGI_PENDING_SET,
		.len		= VGIC_NR_SGIS,
		.handle_mmio	= handle_mmio_sgi_set,
	},
	{}
};

static bool vgic_v2_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
				struct kvm_exit_mmio *mmio)
{
	unsigned long base = vcpu->kvm->arch.vgic.vgic_dist_base;

	if (!is_in_range(mmio->phys_addr, mmio->len, base,
			 KVM_VGIC_V2_DIST_SIZE))
		return false;

	/* GICv2 does not support accesses wider than 32 bits */
	if (mmio->len > 4) {
		kvm_inject_dabt(vcpu, mmio->phys_addr);
		return true;
	}

	return vgic_handle_mmio_range(vcpu, run, mmio, vgic_dist_ranges, base);
}

static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg)
{
	struct kvm *kvm = vcpu->kvm;
	struct vgic_dist *dist = &kvm->arch.vgic;
	int nrcpus = atomic_read(&kvm->online_vcpus);
	u8 target_cpus;
	int sgi, mode, c, vcpu_id;

	vcpu_id = vcpu->vcpu_id;

	sgi = reg & 0xf;
	target_cpus = (reg >> 16) & 0xff;
	mode = (reg >> 24) & 3;

	switch (mode) {
	case 0:
		if (!target_cpus)
			return;
		break;

	case 1:
		target_cpus = ((1 << nrcpus) - 1) & ~(1 << vcpu_id) & 0xff;
		break;

	case 2:
		target_cpus = 1 << vcpu_id;
		break;
	}

	kvm_for_each_vcpu(c, vcpu, kvm) {
		if (target_cpus & 1) {
			/* Flag the SGI as pending */
			vgic_dist_irq_set_pending(vcpu, sgi);
			*vgic_get_sgi_sources(dist, c, sgi) |= 1 << vcpu_id;
			kvm_debug("SGI%d from CPU%d to CPU%d\n",
				  sgi, vcpu_id, c);
		}

		target_cpus >>= 1;
	}
}

static bool vgic_v2_queue_sgi(struct kvm_vcpu *vcpu, int irq)
{
	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
	unsigned long sources;
	int vcpu_id = vcpu->vcpu_id;
	int c;

	sources = *vgic_get_sgi_sources(dist, vcpu_id, irq);

	for_each_set_bit(c, &sources, dist->nr_cpus) {
		if (vgic_queue_irq(vcpu, c, irq))
			clear_bit(c, &sources);
	}

	*vgic_get_sgi_sources(dist, vcpu_id, irq) = sources;

	/*
	 * If the sources bitmap has been cleared it means that we
	 * could queue all the SGIs onto link registers (see the
	 * clear_bit above), and therefore we are done with them in
	 * our emulated gic and can get rid of them.
	 */
	if (!sources) {
		vgic_dist_irq_clear_pending(vcpu, irq);
		vgic_cpu_irq_clear(vcpu, irq);
		return true;
	}

	return false;
}

/**
 * kvm_vgic_map_resources - Configure global VGIC state before running any VCPUs
 * @kvm: pointer to the kvm struct
 *
 * Map the virtual CPU interface into the VM before running any VCPUs.  We
 * can't do this at creation time, because user space must first set the
 * virtual CPU interface address in the guest physical address space.
 */
static int vgic_v2_map_resources(struct kvm *kvm,
				 const struct vgic_params *params)
{
	int ret = 0;

	if (!irqchip_in_kernel(kvm))
		return 0;

	mutex_lock(&kvm->lock);

	if (vgic_ready(kvm))
		goto out;

	if (IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_dist_base) ||
	    IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_cpu_base)) {
		kvm_err("Need to set vgic cpu and dist addresses first\n");
		ret = -ENXIO;
		goto out;
	}

	/*
	 * Initialize the vgic if this hasn't already been done on demand by
	 * accessing the vgic state from userspace.
	 */
	ret = vgic_init(kvm);
	if (ret) {
		kvm_err("Unable to allocate maps\n");
		goto out;
	}

	ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base,
				    params->vcpu_base, KVM_VGIC_V2_CPU_SIZE,
				    true);
	if (ret) {
		kvm_err("Unable to remap VGIC CPU to VCPU\n");
		goto out;
	}

	kvm->arch.vgic.ready = true;
out:
	if (ret)
		kvm_vgic_destroy(kvm);
	mutex_unlock(&kvm->lock);
	return ret;
}

static void vgic_v2_add_sgi_source(struct kvm_vcpu *vcpu, int irq, int source)
{
	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;

	*vgic_get_sgi_sources(dist, vcpu->vcpu_id, irq) |= 1 << source;
}

static int vgic_v2_init_model(struct kvm *kvm)
{
	int i;

	for (i = VGIC_NR_PRIVATE_IRQS; i < kvm->arch.vgic.nr_irqs; i += 4)
		vgic_set_target_reg(kvm, 0, i);

	return 0;
}

void vgic_v2_init_emulation(struct kvm *kvm)
{
	struct vgic_dist *dist = &kvm->arch.vgic;

	dist->vm_ops.handle_mmio = vgic_v2_handle_mmio;
	dist->vm_ops.queue_sgi = vgic_v2_queue_sgi;
	dist->vm_ops.add_sgi_source = vgic_v2_add_sgi_source;
	dist->vm_ops.init_model = vgic_v2_init_model;
	dist->vm_ops.map_resources = vgic_v2_map_resources;

	kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
}

static bool handle_cpu_mmio_misc(struct kvm_vcpu *vcpu,
				 struct kvm_exit_mmio *mmio, phys_addr_t offset)
{
	bool updated = false;
	struct vgic_vmcr vmcr;
	u32 *vmcr_field;
	u32 reg;

	vgic_get_vmcr(vcpu, &vmcr);

	switch (offset & ~0x3) {
	case GIC_CPU_CTRL:
		vmcr_field = &vmcr.ctlr;
		break;
	case GIC_CPU_PRIMASK:
		vmcr_field = &vmcr.pmr;
		break;
	case GIC_CPU_BINPOINT:
		vmcr_field = &vmcr.bpr;
		break;
	case GIC_CPU_ALIAS_BINPOINT:
		vmcr_field = &vmcr.abpr;
		break;
	default:
		BUG();
	}

	if (!mmio->is_write) {
		reg = *vmcr_field;
		mmio_data_write(mmio, ~0, reg);
	} else {
		reg = mmio_data_read(mmio, ~0);
		if (reg != *vmcr_field) {
			*vmcr_field = reg;
			vgic_set_vmcr(vcpu, &vmcr);
			updated = true;
		}
	}
	return updated;
}

static bool handle_mmio_abpr(struct kvm_vcpu *vcpu,
			     struct kvm_exit_mmio *mmio, phys_addr_t offset)
{
	return handle_cpu_mmio_misc(vcpu, mmio, GIC_CPU_ALIAS_BINPOINT);
}

static bool handle_cpu_mmio_ident(struct kvm_vcpu *vcpu,
				  struct kvm_exit_mmio *mmio,
				  phys_addr_t offset)
{
	u32 reg;

	if (mmio->is_write)
		return false;

	/* GICC_IIDR */
	reg = (PRODUCT_ID_KVM << 20) |
	      (GICC_ARCH_VERSION_V2 << 16) |
	      (IMPLEMENTER_ARM << 0);
	mmio_data_write(mmio, ~0, reg);
	return false;
}

/*
 * CPU Interface Register accesses - these are not accessed by the VM, but by
 * user space for saving and restoring VGIC state.
 */
static const struct vgic_io_range vgic_cpu_ranges[] = {
	{
		.base		= GIC_CPU_CTRL,
		.len		= 12,
		.handle_mmio	= handle_cpu_mmio_misc,
	},
	{
		.base		= GIC_CPU_ALIAS_BINPOINT,
		.len		= 4,
		.handle_mmio	= handle_mmio_abpr,
	},
	{
		.base		= GIC_CPU_ACTIVEPRIO,
		.len		= 16,
		.handle_mmio	= handle_mmio_raz_wi,
	},
	{
		.base		= GIC_CPU_IDENT,
		.len		= 4,
		.handle_mmio	= handle_cpu_mmio_ident,
	},
};

static int vgic_attr_regs_access(struct kvm_device *dev,
				 struct kvm_device_attr *attr,
				 u32 *reg, bool is_write)
{
	const struct vgic_io_range *r = NULL, *ranges;
	phys_addr_t offset;
	int ret, cpuid, c;
	struct kvm_vcpu *vcpu, *tmp_vcpu;
	struct vgic_dist *vgic;
	struct kvm_exit_mmio mmio;

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

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

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

	if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) {
		ret = -EINVAL;
		goto out;
	}

	vcpu = kvm_get_vcpu(dev->kvm, cpuid);
	vgic = &dev->kvm->arch.vgic;

	mmio.len = 4;
	mmio.is_write = is_write;
	if (is_write)
		mmio_data_write(&mmio, ~0, *reg);
	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
		mmio.phys_addr = vgic->vgic_dist_base + offset;
		ranges = vgic_dist_ranges;
		break;
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
		mmio.phys_addr = vgic->vgic_cpu_base + offset;
		ranges = vgic_cpu_ranges;
		break;
	default:
		BUG();
	}
	r = vgic_find_range(ranges, &mmio, offset);

	if (unlikely(!r || !r->handle_mmio)) {
		ret = -ENXIO;
		goto out;
	}


	spin_lock(&vgic->lock);

	/*
	 * Ensure that no other VCPU is running by checking the vcpu->cpu
	 * field.  If no other VPCUs are running we can safely access the VGIC
	 * state, because even if another VPU is run after this point, that
	 * VCPU will not touch the vgic state, because it will block on
	 * getting the vgic->lock in kvm_vgic_sync_hwstate().
	 */
	kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) {
		if (unlikely(tmp_vcpu->cpu != -1)) {
			ret = -EBUSY;
			goto out_vgic_unlock;
		}
	}

	/*
	 * Move all pending IRQs from the LRs on all VCPUs so the pending
	 * state can be properly represented in the register state accessible
	 * through this API.
	 */
	kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm)
		vgic_unqueue_irqs(tmp_vcpu);

	offset -= r->base;
	r->handle_mmio(vcpu, &mmio, offset);

	if (!is_write)
		*reg = mmio_data_read(&mmio, ~0);

	ret = 0;
out_vgic_unlock:
	spin_unlock(&vgic->lock);
out:
	mutex_unlock(&dev->kvm->lock);
	return ret;
}

static int vgic_v2_create(struct kvm_device *dev, u32 type)
{
	return kvm_vgic_create(dev->kvm, type);
}

static void vgic_v2_destroy(struct kvm_device *dev)
{
	kfree(dev);
}

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(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(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)
{
	phys_addr_t offset;

	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:
		offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
		return vgic_has_attr_regs(vgic_dist_ranges, offset);
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
		offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
		return vgic_has_attr_regs(vgic_cpu_ranges, offset);
	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_v2_create,
	.destroy = vgic_v2_destroy,
	.set_attr = vgic_v2_set_attr,
	.get_attr = vgic_v2_get_attr,
	.has_attr = vgic_v2_has_attr,
};