arch/arm64/kvm/vgic/vgic-mmio-v2.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * VGICv2 MMIO handling functions
  */

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

 #include <kvm/iodev.h>
 #include <kvm/arm_vgic.h>

 #include "vgic.h"
 #include "vgic-mmio.h"

 /*
  * The Revision field in the IIDR have the following meanings:
  *
  * Revision 1: Report GICv2 interrupts as group 0 instead of group 1
  * Revision 2: Interrupt groups are guest-configurable and signaled using
  * 	       their configured groups.
  */

 static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)
 {
 	struct vgic_dist *vgic = &vcpu->kvm->arch.vgic;
 	u32 value;

 	switch (addr & 0x0c) {
 	case GIC_DIST_CTRL:
 		value = vgic->enabled ? GICD_ENABLE : 0;
 		break;
 	case GIC_DIST_CTR:
 		value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS;
 		value = (value >> 5) - 1;
 		value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
 		break;
 	case GIC_DIST_IIDR:
 		value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) |
 			(vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) |
 			(IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT);
 		break;
 	default:
 		return 0;
 	}

 	return value;
 }

 static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
 				    gpa_t addr, unsigned int len,
 				    unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 	bool was_enabled = dist->enabled;

 	switch (addr & 0x0c) {
 	case GIC_DIST_CTRL:
 		dist->enabled = val & GICD_ENABLE;
 		if (!was_enabled && dist->enabled)
 			vgic_kick_vcpus(vcpu->kvm);
 		break;
 	case GIC_DIST_CTR:
 	case GIC_DIST_IIDR:
 		/* Nothing to do */
 		return;
 	}
 }

 static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len,
 					   unsigned long val)
 {
 	switch (addr & 0x0c) {
 	case GIC_DIST_IIDR:
 		if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
 			return -EINVAL;

 		/*
 		 * If we observe a write to GICD_IIDR we know that userspace
 		 * has been updated and has had a chance to cope with older
 		 * kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting
 		 * interrupts as group 1, and therefore we now allow groups to
 		 * be user writable.  Doing this by default would break
 		 * migration from old kernels to new kernels with legacy
 		 * userspace.
 		 */
 		vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
 		return 0;
 	}

 	vgic_mmio_write_v2_misc(vcpu, addr, len, val);
 	return 0;
 }

 static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len,
 					    unsigned long val)
 {
 	if (vcpu->kvm->arch.vgic.v2_groups_user_writable)
 		vgic_mmio_write_group(vcpu, addr, len, val);

 	return 0;
 }

 static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
 				 gpa_t addr, unsigned int len,
 				 unsigned long val)
 {
 	int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
 	int intid = val & 0xf;
 	int targets = (val >> 16) & 0xff;
 	int mode = (val >> 24) & 0x03;
 	int c;
 	struct kvm_vcpu *vcpu;
 	unsigned long flags;

 	switch (mode) {
 	case 0x0:		/* as specified by targets */
 		break;
 	case 0x1:
 		targets = (1U << nr_vcpus) - 1;			/* all, ... */
 		targets &= ~(1U << source_vcpu->vcpu_id);	/* but self */
 		break;
 	case 0x2:		/* this very vCPU only */
 		targets = (1U << source_vcpu->vcpu_id);
 		break;
 	case 0x3:		/* reserved */
 		return;
 	}

 	kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
 		struct vgic_irq *irq;

 		if (!(targets & (1U << c)))
 			continue;

 		irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);

 		raw_spin_lock_irqsave(&irq->irq_lock, flags);
 		irq->pending_latch = true;
 		irq->source |= 1U << source_vcpu->vcpu_id;

 		vgic_queue_irq_unlock(source_vcpu->kvm, irq, flags);
 		vgic_put_irq(source_vcpu->kvm, irq);
 	}
 }

 static unsigned long vgic_mmio_read_target(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len)
 {
 	u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
 	int i;
 	u64 val = 0;

 	for (i = 0; i < len; i++) {
 		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

 		val |= (u64)irq->targets << (i * 8);

 		vgic_put_irq(vcpu->kvm, irq);
 	}

 	return val;
 }

 static void vgic_mmio_write_target(struct kvm_vcpu *vcpu,
 				   gpa_t addr, unsigned int len,
 				   unsigned long val)
 {
 	u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
 	u8 cpu_mask = GENMASK(atomic_read(&vcpu->kvm->online_vcpus) - 1, 0);
 	int i;
 	unsigned long flags;

 	/* GICD_ITARGETSR[0-7] are read-only */
 	if (intid < VGIC_NR_PRIVATE_IRQS)
 		return;

 	for (i = 0; i < len; i++) {
 		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid + i);
 		int target;

 		raw_spin_lock_irqsave(&irq->irq_lock, flags);

 		irq->targets = (val >> (i * 8)) & cpu_mask;
 		target = irq->targets ? __ffs(irq->targets) : 0;
 		irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);

 		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 }

 static unsigned long vgic_mmio_read_sgipend(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)
 {
 	u32 intid = addr & 0x0f;
 	int i;
 	u64 val = 0;

 	for (i = 0; i < len; i++) {
 		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

 		val |= (u64)irq->source << (i * 8);

 		vgic_put_irq(vcpu->kvm, irq);
 	}
 	return val;
 }

 static void vgic_mmio_write_sgipendc(struct kvm_vcpu *vcpu,
 				     gpa_t addr, unsigned int len,
 				     unsigned long val)
 {
 	u32 intid = addr & 0x0f;
 	int i;
 	unsigned long flags;

 	for (i = 0; i < len; i++) {
 		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

 		raw_spin_lock_irqsave(&irq->irq_lock, flags);

 		irq->source &= ~((val >> (i * 8)) & 0xff);
 		if (!irq->source)
 			irq->pending_latch = false;

 		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 }

 static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
 				     gpa_t addr, unsigned int len,
 				     unsigned long val)
 {
 	u32 intid = addr & 0x0f;
 	int i;
 	unsigned long flags;

 	for (i = 0; i < len; i++) {
 		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

 		raw_spin_lock_irqsave(&irq->irq_lock, flags);

 		irq->source |= (val >> (i * 8)) & 0xff;

 		if (irq->source) {
 			irq->pending_latch = true;
 			vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
 		} else {
 			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 		}
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 }

 #define GICC_ARCH_VERSION_V2	0x2

 /* These are for userland accesses only, there is no guest-facing emulation. */
 static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len)
 {
 	struct vgic_vmcr vmcr;
 	u32 val;

 	vgic_get_vmcr(vcpu, &vmcr);

 	switch (addr & 0xff) {
 	case GIC_CPU_CTRL:
 		val = vmcr.grpen0 << GIC_CPU_CTRL_EnableGrp0_SHIFT;
 		val |= vmcr.grpen1 << GIC_CPU_CTRL_EnableGrp1_SHIFT;
 		val |= vmcr.ackctl << GIC_CPU_CTRL_AckCtl_SHIFT;
 		val |= vmcr.fiqen << GIC_CPU_CTRL_FIQEn_SHIFT;
 		val |= vmcr.cbpr << GIC_CPU_CTRL_CBPR_SHIFT;
 		val |= vmcr.eoim << GIC_CPU_CTRL_EOImodeNS_SHIFT;

 		break;
 	case GIC_CPU_PRIMASK:
 		/*
 		 * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
 		 * the PMR field as GICH_VMCR.VMPriMask rather than
 		 * GICC_PMR.Priority, so we expose the upper five bits of
 		 * priority mask to userspace using the lower bits in the
 		 * unsigned long.
 		 */
 		val = (vmcr.pmr & GICV_PMR_PRIORITY_MASK) >>
 			GICV_PMR_PRIORITY_SHIFT;
 		break;
 	case GIC_CPU_BINPOINT:
 		val = vmcr.bpr;
 		break;
 	case GIC_CPU_ALIAS_BINPOINT:
 		val = vmcr.abpr;
 		break;
 	case GIC_CPU_IDENT:
 		val = ((PRODUCT_ID_KVM << 20) |
 		       (GICC_ARCH_VERSION_V2 << 16) |
 		       IMPLEMENTER_ARM);
 		break;
 	default:
 		return 0;
 	}

 	return val;
 }

 static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
 				   gpa_t addr, unsigned int len,
 				   unsigned long val)
 {
 	struct vgic_vmcr vmcr;

 	vgic_get_vmcr(vcpu, &vmcr);

 	switch (addr & 0xff) {
 	case GIC_CPU_CTRL:
 		vmcr.grpen0 = !!(val & GIC_CPU_CTRL_EnableGrp0);
 		vmcr.grpen1 = !!(val & GIC_CPU_CTRL_EnableGrp1);
 		vmcr.ackctl = !!(val & GIC_CPU_CTRL_AckCtl);
 		vmcr.fiqen = !!(val & GIC_CPU_CTRL_FIQEn);
 		vmcr.cbpr = !!(val & GIC_CPU_CTRL_CBPR);
 		vmcr.eoim = !!(val & GIC_CPU_CTRL_EOImodeNS);

 		break;
 	case GIC_CPU_PRIMASK:
 		/*
 		 * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
 		 * the PMR field as GICH_VMCR.VMPriMask rather than
 		 * GICC_PMR.Priority, so we expose the upper five bits of
 		 * priority mask to userspace using the lower bits in the
 		 * unsigned long.
 		 */
 		vmcr.pmr = (val << GICV_PMR_PRIORITY_SHIFT) &
 			GICV_PMR_PRIORITY_MASK;
 		break;
 	case GIC_CPU_BINPOINT:
 		vmcr.bpr = val;
 		break;
 	case GIC_CPU_ALIAS_BINPOINT:
 		vmcr.abpr = val;
 		break;
 	}

 	vgic_set_vmcr(vcpu, &vmcr);
 }

 static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
 					gpa_t addr, unsigned int len)
 {
 	int n; /* which APRn is this */

 	n = (addr >> 2) & 0x3;

 	if (kvm_vgic_global_state.type == VGIC_V2) {
 		/* GICv2 hardware systems support max. 32 groups */
 		if (n != 0)
 			return 0;
 		return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
 	} else {
 		struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;

 		if (n > vgic_v3_max_apr_idx(vcpu))
 			return 0;

 		n = array_index_nospec(n, 4);

 		/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
 		return vgicv3->vgic_ap1r[n];
 	}
 }

 static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
 				gpa_t addr, unsigned int len,
 				unsigned long val)
 {
 	int n; /* which APRn is this */

 	n = (addr >> 2) & 0x3;

 	if (kvm_vgic_global_state.type == VGIC_V2) {
 		/* GICv2 hardware systems support max. 32 groups */
 		if (n != 0)
 			return;
 		vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
 	} else {
 		struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;

 		if (n > vgic_v3_max_apr_idx(vcpu))
 			return;

 		n = array_index_nospec(n, 4);

 		/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
 		vgicv3->vgic_ap1r[n] = val;
 	}
 }

 static const struct vgic_register_region vgic_v2_dist_registers[] = {
 	REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL,
 		vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
 		NULL, vgic_mmio_uaccess_write_v2_misc,
 		12, VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
 		vgic_mmio_read_group, vgic_mmio_write_group,
 		NULL, vgic_mmio_uaccess_write_v2_group, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
 		vgic_mmio_read_enable, vgic_mmio_write_senable,
 		NULL, vgic_uaccess_write_senable, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
 		vgic_mmio_read_enable, vgic_mmio_write_cenable,
 		NULL, vgic_uaccess_write_cenable, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
 		vgic_mmio_read_pending, vgic_mmio_write_spending,
 		NULL, vgic_uaccess_write_spending, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
 		vgic_mmio_read_pending, vgic_mmio_write_cpending,
 		NULL, vgic_uaccess_write_cpending, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
 		vgic_mmio_read_active, vgic_mmio_write_sactive,
 		vgic_uaccess_read_active, vgic_mmio_uaccess_write_sactive, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
 		vgic_mmio_read_active, vgic_mmio_write_cactive,
 		vgic_uaccess_read_active, vgic_mmio_uaccess_write_cactive, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
 		vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
 		8, VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
 		vgic_mmio_read_target, vgic_mmio_write_target, NULL, NULL, 8,
 		VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
 		vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
 		vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
 		vgic_mmio_read_sgipend, vgic_mmio_write_sgipendc, 16,
 		VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
 		vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16,
 		VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 };

 static const struct vgic_register_region vgic_v2_cpu_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
 		vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 };

 unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
 {
 	dev->regions = vgic_v2_dist_registers;
 	dev->nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);

 	kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);

 	return SZ_4K;
 }

 int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
 	const struct vgic_register_region *region;
 	struct vgic_io_device iodev;
 	struct vgic_reg_attr reg_attr;
 	struct kvm_vcpu *vcpu;
 	gpa_t addr;
 	int ret;

 	ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
 	if (ret)
 		return ret;

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

 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 		iodev.regions = vgic_v2_dist_registers;
 		iodev.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
 		iodev.base_addr = 0;
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 		iodev.regions = vgic_v2_cpu_registers;
 		iodev.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers);
 		iodev.base_addr = 0;
 		break;
 	default:
 		return -ENXIO;
 	}

 	/* We only support aligned 32-bit accesses. */
 	if (addr & 3)
 		return -ENXIO;

 	region = vgic_get_mmio_region(vcpu, &iodev, addr, sizeof(u32));
 	if (!region)
 		return -ENXIO;

 	return 0;
 }

 int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 			  int offset, u32 *val)
 {
 	struct vgic_io_device dev = {
 		.regions = vgic_v2_cpu_registers,
 		.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
 		.iodev_type = IODEV_CPUIF,
 	};

 	return vgic_uaccess(vcpu, &dev, is_write, offset, val);
 }

 int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 			 int offset, u32 *val)
 {
 	struct vgic_io_device dev = {
 		.regions = vgic_v2_dist_registers,
 		.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers),
 		.iodev_type = IODEV_DIST,
 	};

 	return vgic_uaccess(vcpu, &dev, is_write, offset, val);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* VGICv2 MMIO handling functions
	*/

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

	#include <kvm/iodev.h>
	#include <kvm/arm_vgic.h>

	#include "vgic.h"
	#include "vgic-mmio.h"

	/*
	* The Revision field in the IIDR have the following meanings:
	*
	* Revision 1: Report GICv2 interrupts as group 0 instead of group 1
	* Revision 2: Interrupt groups are guest-configurable and signaled using
	* their configured groups.
	*/

	static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len)
	{
	struct vgic_dist *vgic = &vcpu->kvm->arch.vgic;
	u32 value;

	switch (addr & 0x0c) {
	case GIC_DIST_CTRL:
	value = vgic->enabled ? GICD_ENABLE : 0;
	break;
	case GIC_DIST_CTR:
	value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS;
	value = (value >> 5) - 1;
	value \|= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
	break;
	case GIC_DIST_IIDR:
	value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) \|
	(vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) \|
	(IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT);
	break;
	default:
	return 0;
	}

	return value;
	}

	static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
	bool was_enabled = dist->enabled;

	switch (addr & 0x0c) {
	case GIC_DIST_CTRL:
	dist->enabled = val & GICD_ENABLE;
	if (!was_enabled && dist->enabled)
	vgic_kick_vcpus(vcpu->kvm);
	break;
	case GIC_DIST_CTR:
	case GIC_DIST_IIDR:
	/* Nothing to do */
	return;
	}
	}

	static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	switch (addr & 0x0c) {
	case GIC_DIST_IIDR:
	if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
	return -EINVAL;

	/*
	* If we observe a write to GICD_IIDR we know that userspace
	* has been updated and has had a chance to cope with older
	* kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting
	* interrupts as group 1, and therefore we now allow groups to
	* be user writable. Doing this by default would break
	* migration from old kernels to new kernels with legacy
	* userspace.
	*/
	vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
	return 0;
	}

	vgic_mmio_write_v2_misc(vcpu, addr, len, val);
	return 0;
	}

	static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	if (vcpu->kvm->arch.vgic.v2_groups_user_writable)
	vgic_mmio_write_group(vcpu, addr, len, val);

	return 0;
	}

	static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
	int intid = val & 0xf;
	int targets = (val >> 16) & 0xff;
	int mode = (val >> 24) & 0x03;
	int c;
	struct kvm_vcpu *vcpu;
	unsigned long flags;

	switch (mode) {
	case 0x0: /* as specified by targets */
	break;
	case 0x1:
	targets = (1U << nr_vcpus) - 1; /* all, ... */
	targets &= ~(1U << source_vcpu->vcpu_id); /* but self */
	break;
	case 0x2: /* this very vCPU only */
	targets = (1U << source_vcpu->vcpu_id);
	break;
	case 0x3: /* reserved */
	return;
	}

	kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
	struct vgic_irq *irq;

	if (!(targets & (1U << c)))
	continue;

	irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);

	raw_spin_lock_irqsave(&irq->irq_lock, flags);
	irq->pending_latch = true;
	irq->source \|= 1U << source_vcpu->vcpu_id;

	vgic_queue_irq_unlock(source_vcpu->kvm, irq, flags);
	vgic_put_irq(source_vcpu->kvm, irq);
	}
	}

	static unsigned long vgic_mmio_read_target(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len)
	{
	u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
	int i;
	u64 val = 0;

	for (i = 0; i < len; i++) {
	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

	val \|= (u64)irq->targets << (i * 8);

	vgic_put_irq(vcpu->kvm, irq);
	}

	return val;
	}

	static void vgic_mmio_write_target(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
	u8 cpu_mask = GENMASK(atomic_read(&vcpu->kvm->online_vcpus) - 1, 0);
	int i;
	unsigned long flags;

	/* GICD_ITARGETSR[0-7] are read-only */
	if (intid < VGIC_NR_PRIVATE_IRQS)
	return;

	for (i = 0; i < len; i++) {
	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid + i);
	int target;

	raw_spin_lock_irqsave(&irq->irq_lock, flags);

	irq->targets = (val >> (i * 8)) & cpu_mask;
	target = irq->targets ? __ffs(irq->targets) : 0;
	irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);

	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
	vgic_put_irq(vcpu->kvm, irq);
	}
	}

	static unsigned long vgic_mmio_read_sgipend(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len)
	{
	u32 intid = addr & 0x0f;
	int i;
	u64 val = 0;

	for (i = 0; i < len; i++) {
	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

	val \|= (u64)irq->source << (i * 8);

	vgic_put_irq(vcpu->kvm, irq);
	}
	return val;
	}

	static void vgic_mmio_write_sgipendc(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	u32 intid = addr & 0x0f;
	int i;
	unsigned long flags;

	for (i = 0; i < len; i++) {
	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

	raw_spin_lock_irqsave(&irq->irq_lock, flags);

	irq->source &= ~((val >> (i * 8)) & 0xff);
	if (!irq->source)
	irq->pending_latch = false;

	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
	vgic_put_irq(vcpu->kvm, irq);
	}
	}

	static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	u32 intid = addr & 0x0f;
	int i;
	unsigned long flags;

	for (i = 0; i < len; i++) {
	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);

	raw_spin_lock_irqsave(&irq->irq_lock, flags);

	irq->source \|= (val >> (i * 8)) & 0xff;

	if (irq->source) {
	irq->pending_latch = true;
	vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
	} else {
	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
	}
	vgic_put_irq(vcpu->kvm, irq);
	}
	}

	#define GICC_ARCH_VERSION_V2 0x2

	/* These are for userland accesses only, there is no guest-facing emulation. */
	static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len)
	{
	struct vgic_vmcr vmcr;
	u32 val;

	vgic_get_vmcr(vcpu, &vmcr);

	switch (addr & 0xff) {
	case GIC_CPU_CTRL:
	val = vmcr.grpen0 << GIC_CPU_CTRL_EnableGrp0_SHIFT;
	val \|= vmcr.grpen1 << GIC_CPU_CTRL_EnableGrp1_SHIFT;
	val \|= vmcr.ackctl << GIC_CPU_CTRL_AckCtl_SHIFT;
	val \|= vmcr.fiqen << GIC_CPU_CTRL_FIQEn_SHIFT;
	val \|= vmcr.cbpr << GIC_CPU_CTRL_CBPR_SHIFT;
	val \|= vmcr.eoim << GIC_CPU_CTRL_EOImodeNS_SHIFT;

	break;
	case GIC_CPU_PRIMASK:
	/*
	* Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
	* the PMR field as GICH_VMCR.VMPriMask rather than
	* GICC_PMR.Priority, so we expose the upper five bits of
	* priority mask to userspace using the lower bits in the
	* unsigned long.
	*/
	val = (vmcr.pmr & GICV_PMR_PRIORITY_MASK) >>
	GICV_PMR_PRIORITY_SHIFT;
	break;
	case GIC_CPU_BINPOINT:
	val = vmcr.bpr;
	break;
	case GIC_CPU_ALIAS_BINPOINT:
	val = vmcr.abpr;
	break;
	case GIC_CPU_IDENT:
	val = ((PRODUCT_ID_KVM << 20) \|
	(GICC_ARCH_VERSION_V2 << 16) \|
	IMPLEMENTER_ARM);
	break;
	default:
	return 0;
	}

	return val;
	}

	static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	struct vgic_vmcr vmcr;

	vgic_get_vmcr(vcpu, &vmcr);

	switch (addr & 0xff) {
	case GIC_CPU_CTRL:
	vmcr.grpen0 = !!(val & GIC_CPU_CTRL_EnableGrp0);
	vmcr.grpen1 = !!(val & GIC_CPU_CTRL_EnableGrp1);
	vmcr.ackctl = !!(val & GIC_CPU_CTRL_AckCtl);
	vmcr.fiqen = !!(val & GIC_CPU_CTRL_FIQEn);
	vmcr.cbpr = !!(val & GIC_CPU_CTRL_CBPR);
	vmcr.eoim = !!(val & GIC_CPU_CTRL_EOImodeNS);

	break;
	case GIC_CPU_PRIMASK:
	/*
	* Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
	* the PMR field as GICH_VMCR.VMPriMask rather than
	* GICC_PMR.Priority, so we expose the upper five bits of
	* priority mask to userspace using the lower bits in the
	* unsigned long.
	*/
	vmcr.pmr = (val << GICV_PMR_PRIORITY_SHIFT) &
	GICV_PMR_PRIORITY_MASK;
	break;
	case GIC_CPU_BINPOINT:
	vmcr.bpr = val;
	break;
	case GIC_CPU_ALIAS_BINPOINT:
	vmcr.abpr = val;
	break;
	}

	vgic_set_vmcr(vcpu, &vmcr);
	}

	static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len)
	{
	int n; /* which APRn is this */

	n = (addr >> 2) & 0x3;

	if (kvm_vgic_global_state.type == VGIC_V2) {
	/* GICv2 hardware systems support max. 32 groups */
	if (n != 0)
	return 0;
	return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
	} else {
	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;

	if (n > vgic_v3_max_apr_idx(vcpu))
	return 0;

	n = array_index_nospec(n, 4);

	/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
	return vgicv3->vgic_ap1r[n];
	}
	}

	static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
	gpa_t addr, unsigned int len,
	unsigned long val)
	{
	int n; /* which APRn is this */

	n = (addr >> 2) & 0x3;

	if (kvm_vgic_global_state.type == VGIC_V2) {
	/* GICv2 hardware systems support max. 32 groups */
	if (n != 0)
	return;
	vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
	} else {
	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;

	if (n > vgic_v3_max_apr_idx(vcpu))
	return;

	n = array_index_nospec(n, 4);

	/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
	vgicv3->vgic_ap1r[n] = val;
	}
	}

	static const struct vgic_register_region vgic_v2_dist_registers[] = {
	REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL,
	vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
	NULL, vgic_mmio_uaccess_write_v2_misc,
	12, VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
	vgic_mmio_read_group, vgic_mmio_write_group,
	NULL, vgic_mmio_uaccess_write_v2_group, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
	vgic_mmio_read_enable, vgic_mmio_write_senable,
	NULL, vgic_uaccess_write_senable, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
	vgic_mmio_read_enable, vgic_mmio_write_cenable,
	NULL, vgic_uaccess_write_cenable, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
	vgic_mmio_read_pending, vgic_mmio_write_spending,
	NULL, vgic_uaccess_write_spending, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
	vgic_mmio_read_pending, vgic_mmio_write_cpending,
	NULL, vgic_uaccess_write_cpending, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
	vgic_mmio_read_active, vgic_mmio_write_sactive,
	vgic_uaccess_read_active, vgic_mmio_uaccess_write_sactive, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
	vgic_mmio_read_active, vgic_mmio_write_cactive,
	vgic_uaccess_read_active, vgic_mmio_uaccess_write_cactive, 1,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
	vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
	8, VGIC_ACCESS_32bit \| VGIC_ACCESS_8bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
	vgic_mmio_read_target, vgic_mmio_write_target, NULL, NULL, 8,
	VGIC_ACCESS_32bit \| VGIC_ACCESS_8bit),
	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
	vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
	vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
	vgic_mmio_read_sgipend, vgic_mmio_write_sgipendc, 16,
	VGIC_ACCESS_32bit \| VGIC_ACCESS_8bit),
	REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
	vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16,
	VGIC_ACCESS_32bit \| VGIC_ACCESS_8bit),
	};

	static const struct vgic_register_region vgic_v2_cpu_registers[] = {
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
	vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
	vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
	vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
	vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
	vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
	VGIC_ACCESS_32bit),
	REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
	vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
	VGIC_ACCESS_32bit),
	};

	unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
	{
	dev->regions = vgic_v2_dist_registers;
	dev->nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);

	kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);

	return SZ_4K;
	}

	int vgic_v2_has_attr_regs(struct kvm_device dev, struct kvm_device_attr attr)
	{
	const struct vgic_register_region *region;
	struct vgic_io_device iodev;
	struct vgic_reg_attr reg_attr;
	struct kvm_vcpu *vcpu;
	gpa_t addr;
	int ret;

	ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
	if (ret)
	return ret;

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

	switch (attr->group) {
	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
	iodev.regions = vgic_v2_dist_registers;
	iodev.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
	iodev.base_addr = 0;
	break;
	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
	iodev.regions = vgic_v2_cpu_registers;
	iodev.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers);
	iodev.base_addr = 0;
	break;
	default:
	return -ENXIO;
	}

	/* We only support aligned 32-bit accesses. */
	if (addr & 3)
	return -ENXIO;

	region = vgic_get_mmio_region(vcpu, &iodev, addr, sizeof(u32));
	if (!region)
	return -ENXIO;

	return 0;
	}

	int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
	int offset, u32 *val)
	{
	struct vgic_io_device dev = {
	.regions = vgic_v2_cpu_registers,
	.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
	.iodev_type = IODEV_CPUIF,
	};

	return vgic_uaccess(vcpu, &dev, is_write, offset, val);
	}

	int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
	int offset, u32 *val)
	{
	struct vgic_io_device dev = {
	.regions = vgic_v2_dist_registers,
	.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers),
	.iodev_type = IODEV_DIST,
	};

	return vgic_uaccess(vcpu, &dev, is_write, offset, val);
	}