KVM: arm64: Move virt/kvm/arm to arch/arm64

Now that the 32bit KVM/arm host is a distant memory, let's move the
whole of the KVM/arm64 code into the arm64 tree.

As they said in the song: Welcome Home (Sanitarium).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org

1 files changed, 1088 insertions, 0 deletions

diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c
new file mode 100644
index 000000000000..b2d73fc0d1ef
--- /dev/null
+++ b/arch/arm64/kvm/vgic/vgic-mmio.c
@@ -0,0 +1,1088 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VGIC MMIO handling functions
+ */
+
+#include <linux/bitops.h>
+#include <linux/bsearch.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <kvm/iodev.h>
+#include <kvm/arm_arch_timer.h>
+#include <kvm/arm_vgic.h>
+
+#include "vgic.h"
+#include "vgic-mmio.h"
+
+unsigned long vgic_mmio_read_raz(struct kvm_vcpu *vcpu,
+				 gpa_t addr, unsigned int len)
+{
+	return 0;
+}
+
+unsigned long vgic_mmio_read_rao(struct kvm_vcpu *vcpu,
+				 gpa_t addr, unsigned int len)
+{
+	return -1UL;
+}
+
+void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
+			unsigned int len, unsigned long val)
+{
+	/* Ignore */
+}
+
+int vgic_mmio_uaccess_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
+			       unsigned int len, unsigned long val)
+{
+	/* Ignore */
+	return 0;
+}
+
+unsigned long vgic_mmio_read_group(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 value = 0;
+	int i;
+
+	/* Loop over all IRQs affected by this read */
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		if (irq->group)
+			value |= BIT(i);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return value;
+}
+
+static void vgic_update_vsgi(struct vgic_irq *irq)
+{
+	WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority, irq->group));
+}
+
+void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
+			   unsigned int len, unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		irq->group = !!(val & BIT(i));
+		if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+			vgic_update_vsgi(irq);
+			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+		} else {
+			vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+		}
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+/*
+ * Read accesses to both GICD_ICENABLER and GICD_ISENABLER return the value
+ * of the enabled bit, so there is only one function for both here.
+ */
+unsigned long vgic_mmio_read_enable(struct kvm_vcpu *vcpu,
+				    gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 value = 0;
+	int i;
+
+	/* Loop over all IRQs affected by this read */
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		if (irq->enabled)
+			value |= (1U << i);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return value;
+}
+
+void vgic_mmio_write_senable(struct kvm_vcpu *vcpu,
+			     gpa_t addr, unsigned int len,
+			     unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+			if (!irq->enabled) {
+				struct irq_data *data;
+
+				irq->enabled = true;
+				data = &irq_to_desc(irq->host_irq)->irq_data;
+				while (irqd_irq_disabled(data))
+					enable_irq(irq->host_irq);
+			}
+
+			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+			vgic_put_irq(vcpu->kvm, irq);
+
+			continue;
+		} else if (vgic_irq_is_mapped_level(irq)) {
+			bool was_high = irq->line_level;
+
+			/*
+			 * We need to update the state of the interrupt because
+			 * the guest might have changed the state of the device
+			 * while the interrupt was disabled at the VGIC level.
+			 */
+			irq->line_level = vgic_get_phys_line_level(irq);
+			/*
+			 * Deactivate the physical interrupt so the GIC will let
+			 * us know when it is asserted again.
+			 */
+			if (!irq->active && was_high && !irq->line_level)
+				vgic_irq_set_phys_active(irq, false);
+		}
+		irq->enabled = true;
+		vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
+			     gpa_t addr, unsigned int len,
+			     unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled)
+			disable_irq_nosync(irq->host_irq);
+
+		irq->enabled = false;
+
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+int vgic_uaccess_write_senable(struct kvm_vcpu *vcpu,
+			       gpa_t addr, unsigned int len,
+			       unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		irq->enabled = true;
+		vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return 0;
+}
+
+int vgic_uaccess_write_cenable(struct kvm_vcpu *vcpu,
+			       gpa_t addr, unsigned int len,
+			       unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		irq->enabled = false;
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return 0;
+}
+
+unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
+				     gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 value = 0;
+	int i;
+
+	/* Loop over all IRQs affected by this read */
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+		unsigned long flags;
+		bool val;
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+			int err;
+
+			val = false;
+			err = irq_get_irqchip_state(irq->host_irq,
+						    IRQCHIP_STATE_PENDING,
+						    &val);
+			WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+		} else {
+			val = irq_is_pending(irq);
+		}
+
+		value |= ((u32)val << i);
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return value;
+}
+
+static bool is_vgic_v2_sgi(struct kvm_vcpu *vcpu, struct vgic_irq *irq)
+{
+	return (vgic_irq_is_sgi(irq->intid) &&
+		vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2);
+}
+
+void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		/* GICD_ISPENDR0 SGI bits are WI */
+		if (is_vgic_v2_sgi(vcpu, irq)) {
+			vgic_put_irq(vcpu->kvm, irq);
+			continue;
+		}
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+
+		if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+			/* HW SGI? Ask the GIC to inject it */
+			int err;
+			err = irq_set_irqchip_state(irq->host_irq,
+						    IRQCHIP_STATE_PENDING,
+						    true);
+			WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+
+			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+			vgic_put_irq(vcpu->kvm, irq);
+
+			continue;
+		}
+
+		irq->pending_latch = true;
+		if (irq->hw)
+			vgic_irq_set_phys_active(irq, true);
+
+		vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+int vgic_uaccess_write_spending(struct kvm_vcpu *vcpu,
+				gpa_t addr, unsigned int len,
+				unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		irq->pending_latch = true;
+
+		/*
+		 * GICv2 SGIs are terribly broken. We can't restore
+		 * the source of the interrupt, so just pick the vcpu
+		 * itself as the source...
+		 */
+		if (is_vgic_v2_sgi(vcpu, irq))
+			irq->source |= BIT(vcpu->vcpu_id);
+
+		vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return 0;
+}
+
+/* Must be called with irq->irq_lock held */
+static void vgic_hw_irq_cpending(struct kvm_vcpu *vcpu, struct vgic_irq *irq)
+{
+	irq->pending_latch = false;
+
+	/*
+	 * We don't want the guest to effectively mask the physical
+	 * interrupt by doing a write to SPENDR followed by a write to
+	 * CPENDR for HW interrupts, so we clear the active state on
+	 * the physical side if the virtual interrupt is not active.
+	 * This may lead to taking an additional interrupt on the
+	 * host, but that should not be a problem as the worst that
+	 * can happen is an additional vgic injection.  We also clear
+	 * the pending state to maintain proper semantics for edge HW
+	 * interrupts.
+	 */
+	vgic_irq_set_phys_pending(irq, false);
+	if (!irq->active)
+		vgic_irq_set_phys_active(irq, false);
+}
+
+void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		/* GICD_ICPENDR0 SGI bits are WI */
+		if (is_vgic_v2_sgi(vcpu, irq)) {
+			vgic_put_irq(vcpu->kvm, irq);
+			continue;
+		}
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+
+		if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+			/* HW SGI? Ask the GIC to clear its pending bit */
+			int err;
+			err = irq_set_irqchip_state(irq->host_irq,
+						    IRQCHIP_STATE_PENDING,
+						    false);
+			WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+
+			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+			vgic_put_irq(vcpu->kvm, irq);
+
+			continue;
+		}
+
+		if (irq->hw)
+			vgic_hw_irq_cpending(vcpu, irq);
+		else
+			irq->pending_latch = false;
+
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+int vgic_uaccess_write_cpending(struct kvm_vcpu *vcpu,
+				gpa_t addr, unsigned int len,
+				unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+	unsigned long flags;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		/*
+		 * More fun with GICv2 SGIs! If we're clearing one of them
+		 * from userspace, which source vcpu to clear? Let's not
+		 * even think of it, and blow the whole set.
+		 */
+		if (is_vgic_v2_sgi(vcpu, irq))
+			irq->source = 0;
+
+		irq->pending_latch = false;
+
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return 0;
+}
+
+/*
+ * If we are fiddling with an IRQ's active state, we have to make sure the IRQ
+ * is not queued on some running VCPU's LRs, because then the change to the
+ * active state can be overwritten when the VCPU's state is synced coming back
+ * from the guest.
+ *
+ * For shared interrupts as well as GICv3 private interrupts, we have to
+ * stop all the VCPUs because interrupts can be migrated while we don't hold
+ * the IRQ locks and we don't want to be chasing moving targets.
+ *
+ * For GICv2 private interrupts we don't have to do anything because
+ * userspace accesses to the VGIC state already require all VCPUs to be
+ * stopped, and only the VCPU itself can modify its private interrupts
+ * active state, which guarantees that the VCPU is not running.
+ */
+static void vgic_access_active_prepare(struct kvm_vcpu *vcpu, u32 intid)
+{
+	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 ||
+	    intid >= VGIC_NR_PRIVATE_IRQS)
+		kvm_arm_halt_guest(vcpu->kvm);
+}
+
+/* See vgic_access_active_prepare */
+static void vgic_access_active_finish(struct kvm_vcpu *vcpu, u32 intid)
+{
+	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 ||
+	    intid >= VGIC_NR_PRIVATE_IRQS)
+		kvm_arm_resume_guest(vcpu->kvm);
+}
+
+static unsigned long __vgic_mmio_read_active(struct kvm_vcpu *vcpu,
+					     gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 value = 0;
+	int i;
+
+	/* Loop over all IRQs affected by this read */
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		/*
+		 * Even for HW interrupts, don't evaluate the HW state as
+		 * all the guest is interested in is the virtual state.
+		 */
+		if (irq->active)
+			value |= (1U << i);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return value;
+}
+
+unsigned long vgic_mmio_read_active(struct kvm_vcpu *vcpu,
+				    gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 val;
+
+	mutex_lock(&vcpu->kvm->lock);
+	vgic_access_active_prepare(vcpu, intid);
+
+	val = __vgic_mmio_read_active(vcpu, addr, len);
+
+	vgic_access_active_finish(vcpu, intid);
+	mutex_unlock(&vcpu->kvm->lock);
+
+	return val;
+}
+
+unsigned long vgic_uaccess_read_active(struct kvm_vcpu *vcpu,
+				    gpa_t addr, unsigned int len)
+{
+	return __vgic_mmio_read_active(vcpu, addr, len);
+}
+
+/* Must be called with irq->irq_lock held */
+static void vgic_hw_irq_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+				      bool active, bool is_uaccess)
+{
+	if (is_uaccess)
+		return;
+
+	irq->active = active;
+	vgic_irq_set_phys_active(irq, active);
+}
+
+static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+				    bool active)
+{
+	unsigned long flags;
+	struct kvm_vcpu *requester_vcpu = kvm_get_running_vcpu();
+
+	raw_spin_lock_irqsave(&irq->irq_lock, flags);
+
+	if (irq->hw && !vgic_irq_is_sgi(irq->intid)) {
+		vgic_hw_irq_change_active(vcpu, irq, active, !requester_vcpu);
+	} else if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+		/*
+		 * GICv4.1 VSGI feature doesn't track an active state,
+		 * so let's not kid ourselves, there is nothing we can
+		 * do here.
+		 */
+		irq->active = false;
+	} else {
+		u32 model = vcpu->kvm->arch.vgic.vgic_model;
+		u8 active_source;
+
+		irq->active = active;
+
+		/*
+		 * The GICv2 architecture indicates that the source CPUID for
+		 * an SGI should be provided during an EOI which implies that
+		 * the active state is stored somewhere, but at the same time
+		 * this state is not architecturally exposed anywhere and we
+		 * have no way of knowing the right source.
+		 *
+		 * This may lead to a VCPU not being able to receive
+		 * additional instances of a particular SGI after migration
+		 * for a GICv2 VM on some GIC implementations.  Oh well.
+		 */
+		active_source = (requester_vcpu) ? requester_vcpu->vcpu_id : 0;
+
+		if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
+		    active && vgic_irq_is_sgi(irq->intid))
+			irq->active_source = active_source;
+	}
+
+	if (irq->active)
+		vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+	else
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+}
+
+static void __vgic_mmio_write_cactive(struct kvm_vcpu *vcpu,
+				      gpa_t addr, unsigned int len,
+				      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+		vgic_mmio_change_active(vcpu, irq, false);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+void vgic_mmio_write_cactive(struct kvm_vcpu *vcpu,
+			     gpa_t addr, unsigned int len,
+			     unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+
+	mutex_lock(&vcpu->kvm->lock);
+	vgic_access_active_prepare(vcpu, intid);
+
+	__vgic_mmio_write_cactive(vcpu, addr, len, val);
+
+	vgic_access_active_finish(vcpu, intid);
+	mutex_unlock(&vcpu->kvm->lock);
+}
+
+int vgic_mmio_uaccess_write_cactive(struct kvm_vcpu *vcpu,
+				     gpa_t addr, unsigned int len,
+				     unsigned long val)
+{
+	__vgic_mmio_write_cactive(vcpu, addr, len, val);
+	return 0;
+}
+
+static void __vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
+				      gpa_t addr, unsigned int len,
+				      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+		vgic_mmio_change_active(vcpu, irq, true);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
+			     gpa_t addr, unsigned int len,
+			     unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+
+	mutex_lock(&vcpu->kvm->lock);
+	vgic_access_active_prepare(vcpu, intid);
+
+	__vgic_mmio_write_sactive(vcpu, addr, len, val);
+
+	vgic_access_active_finish(vcpu, intid);
+	mutex_unlock(&vcpu->kvm->lock);
+}
+
+int vgic_mmio_uaccess_write_sactive(struct kvm_vcpu *vcpu,
+				     gpa_t addr, unsigned int len,
+				     unsigned long val)
+{
+	__vgic_mmio_write_sactive(vcpu, addr, len, val);
+	return 0;
+}
+
+unsigned long vgic_mmio_read_priority(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->priority << (i * 8);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return val;
+}
+
+/*
+ * We currently don't handle changing the priority of an interrupt that
+ * is already pending on a VCPU. If there is a need for this, we would
+ * need to make this VCPU exit and re-evaluate the priorities, potentially
+ * leading to this interrupt getting presented now to the guest (if it has
+ * been masked by the priority mask before).
+ */
+void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
+	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);
+		/* Narrow the priority range to what we actually support */
+		irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
+		if (irq->hw && vgic_irq_is_sgi(irq->intid))
+			vgic_update_vsgi(irq);
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+unsigned long vgic_mmio_read_config(struct kvm_vcpu *vcpu,
+				    gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 2);
+	u32 value = 0;
+	int i;
+
+	for (i = 0; i < len * 4; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		if (irq->config == VGIC_CONFIG_EDGE)
+			value |= (2U << (i * 2));
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return value;
+}
+
+void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
+			    gpa_t addr, unsigned int len,
+			    unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 2);
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < len * 4; i++) {
+		struct vgic_irq *irq;
+
+		/*
+		 * The configuration cannot be changed for SGIs in general,
+		 * for PPIs this is IMPLEMENTATION DEFINED. The arch timer
+		 * code relies on PPIs being level triggered, so we also
+		 * make them read-only here.
+		 */
+		if (intid + i < VGIC_NR_PRIVATE_IRQS)
+			continue;
+
+		irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+
+		if (test_bit(i * 2 + 1, &val))
+			irq->config = VGIC_CONFIG_EDGE;
+		else
+			irq->config = VGIC_CONFIG_LEVEL;
+
+		raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+u64 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid)
+{
+	int i;
+	u64 val = 0;
+	int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
+
+	for (i = 0; i < 32; i++) {
+		struct vgic_irq *irq;
+
+		if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs)
+			continue;
+
+		irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+		if (irq->config == VGIC_CONFIG_LEVEL && irq->line_level)
+			val |= (1U << i);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return val;
+}
+
+void vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
+				    const u64 val)
+{
+	int i;
+	int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
+	unsigned long flags;
+
+	for (i = 0; i < 32; i++) {
+		struct vgic_irq *irq;
+		bool new_level;
+
+		if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs)
+			continue;
+
+		irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		/*
+		 * Line level is set irrespective of irq type
+		 * (level or edge) to avoid dependency that VM should
+		 * restore irq config before line level.
+		 */
+		new_level = !!(val & (1U << i));
+		raw_spin_lock_irqsave(&irq->irq_lock, flags);
+		irq->line_level = new_level;
+		if (new_level)
+			vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+		else
+			raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+static int match_region(const void *key, const void *elt)
+{
+	const unsigned int offset = (unsigned long)key;
+	const struct vgic_register_region *region = elt;
+
+	if (offset < region->reg_offset)
+		return -1;
+
+	if (offset >= region->reg_offset + region->len)
+		return 1;
+
+	return 0;
+}
+
+const struct vgic_register_region *
+vgic_find_mmio_region(const struct vgic_register_region *regions,
+		      int nr_regions, unsigned int offset)
+{
+	return bsearch((void *)(uintptr_t)offset, regions, nr_regions,
+		       sizeof(regions[0]), match_region);
+}
+
+void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+{
+	if (kvm_vgic_global_state.type == VGIC_V2)
+		vgic_v2_set_vmcr(vcpu, vmcr);
+	else
+		vgic_v3_set_vmcr(vcpu, vmcr);
+}
+
+void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+{
+	if (kvm_vgic_global_state.type == VGIC_V2)
+		vgic_v2_get_vmcr(vcpu, vmcr);
+	else
+		vgic_v3_get_vmcr(vcpu, vmcr);
+}
+
+/*
+ * kvm_mmio_read_buf() returns a value in a format where it can be converted
+ * to a byte array and be directly observed as the guest wanted it to appear
+ * in memory if it had done the store itself, which is LE for the GIC, as the
+ * guest knows the GIC is always LE.
+ *
+ * We convert this value to the CPUs native format to deal with it as a data
+ * value.
+ */
+unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len)
+{
+	unsigned long data = kvm_mmio_read_buf(val, len);
+
+	switch (len) {
+	case 1:
+		return data;
+	case 2:
+		return le16_to_cpu(data);
+	case 4:
+		return le32_to_cpu(data);
+	default:
+		return le64_to_cpu(data);
+	}
+}
+
+/*
+ * kvm_mmio_write_buf() expects a value in a format such that if converted to
+ * a byte array it is observed as the guest would see it if it could perform
+ * the load directly.  Since the GIC is LE, and the guest knows this, the
+ * guest expects a value in little endian format.
+ *
+ * We convert the data value from the CPUs native format to LE so that the
+ * value is returned in the proper format.
+ */
+void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
+				unsigned long data)
+{
+	switch (len) {
+	case 1:
+		break;
+	case 2:
+		data = cpu_to_le16(data);
+		break;
+	case 4:
+		data = cpu_to_le32(data);
+		break;
+	default:
+		data = cpu_to_le64(data);
+	}
+
+	kvm_mmio_write_buf(buf, len, data);
+}
+
+static
+struct vgic_io_device *kvm_to_vgic_iodev(const struct kvm_io_device *dev)
+{
+	return container_of(dev, struct vgic_io_device, dev);
+}
+
+static bool check_region(const struct kvm *kvm,
+			 const struct vgic_register_region *region,
+			 gpa_t addr, int len)
+{
+	int flags, nr_irqs = kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
+
+	switch (len) {
+	case sizeof(u8):
+		flags = VGIC_ACCESS_8bit;
+		break;
+	case sizeof(u32):
+		flags = VGIC_ACCESS_32bit;
+		break;
+	case sizeof(u64):
+		flags = VGIC_ACCESS_64bit;
+		break;
+	default:
+		return false;
+	}
+
+	if ((region->access_flags & flags) && IS_ALIGNED(addr, len)) {
+		if (!region->bits_per_irq)
+			return true;
+
+		/* Do we access a non-allocated IRQ? */
+		return VGIC_ADDR_TO_INTID(addr, region->bits_per_irq) < nr_irqs;
+	}
+
+	return false;
+}
+
+const struct vgic_register_region *
+vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev,
+		     gpa_t addr, int len)
+{
+	const struct vgic_register_region *region;
+
+	region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
+				       addr - iodev->base_addr);
+	if (!region || !check_region(vcpu->kvm, region, addr, len))
+		return NULL;
+
+	return region;
+}
+
+static int vgic_uaccess_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+			     gpa_t addr, u32 *val)
+{
+	struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+	const struct vgic_register_region *region;
+	struct kvm_vcpu *r_vcpu;
+
+	region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32));
+	if (!region) {
+		*val = 0;
+		return 0;
+	}
+
+	r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
+	if (region->uaccess_read)
+		*val = region->uaccess_read(r_vcpu, addr, sizeof(u32));
+	else
+		*val = region->read(r_vcpu, addr, sizeof(u32));
+
+	return 0;
+}
+
+static int vgic_uaccess_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+			      gpa_t addr, const u32 *val)
+{
+	struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+	const struct vgic_register_region *region;
+	struct kvm_vcpu *r_vcpu;
+
+	region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32));
+	if (!region)
+		return 0;
+
+	r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
+	if (region->uaccess_write)
+		return region->uaccess_write(r_vcpu, addr, sizeof(u32), *val);
+
+	region->write(r_vcpu, addr, sizeof(u32), *val);
+	return 0;
+}
+
+/*
+ * Userland access to VGIC registers.
+ */
+int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
+		 bool is_write, int offset, u32 *val)
+{
+	if (is_write)
+		return vgic_uaccess_write(vcpu, &dev->dev, offset, val);
+	else
+		return vgic_uaccess_read(vcpu, &dev->dev, offset, val);
+}
+
+static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+			      gpa_t addr, int len, void *val)
+{
+	struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+	const struct vgic_register_region *region;
+	unsigned long data = 0;
+
+	region = vgic_get_mmio_region(vcpu, iodev, addr, len);
+	if (!region) {
+		memset(val, 0, len);
+		return 0;
+	}
+
+	switch (iodev->iodev_type) {
+	case IODEV_CPUIF:
+		data = region->read(vcpu, addr, len);
+		break;
+	case IODEV_DIST:
+		data = region->read(vcpu, addr, len);
+		break;
+	case IODEV_REDIST:
+		data = region->read(iodev->redist_vcpu, addr, len);
+		break;
+	case IODEV_ITS:
+		data = region->its_read(vcpu->kvm, iodev->its, addr, len);
+		break;
+	}
+
+	vgic_data_host_to_mmio_bus(val, len, data);
+	return 0;
+}
+
+static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+			       gpa_t addr, int len, const void *val)
+{
+	struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+	const struct vgic_register_region *region;
+	unsigned long data = vgic_data_mmio_bus_to_host(val, len);
+
+	region = vgic_get_mmio_region(vcpu, iodev, addr, len);
+	if (!region)
+		return 0;
+
+	switch (iodev->iodev_type) {
+	case IODEV_CPUIF:
+		region->write(vcpu, addr, len, data);
+		break;
+	case IODEV_DIST:
+		region->write(vcpu, addr, len, data);
+		break;
+	case IODEV_REDIST:
+		region->write(iodev->redist_vcpu, addr, len, data);
+		break;
+	case IODEV_ITS:
+		region->its_write(vcpu->kvm, iodev->its, addr, len, data);
+		break;
+	}
+
+	return 0;
+}
+
+struct kvm_io_device_ops kvm_io_gic_ops = {
+	.read = dispatch_mmio_read,
+	.write = dispatch_mmio_write,
+};
+
+int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
+			     enum vgic_type type)
+{
+	struct vgic_io_device *io_device = &kvm->arch.vgic.dist_iodev;
+	int ret = 0;
+	unsigned int len;
+
+	switch (type) {
+	case VGIC_V2:
+		len = vgic_v2_init_dist_iodev(io_device);
+		break;
+	case VGIC_V3:
+		len = vgic_v3_init_dist_iodev(io_device);
+		break;
+	default:
+		BUG_ON(1);
+	}
+
+	io_device->base_addr = dist_base_address;
+	io_device->iodev_type = IODEV_DIST;
+	io_device->redist_vcpu = NULL;
+
+	mutex_lock(&kvm->slots_lock);
+	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, dist_base_address,
+				      len, &io_device->dev);
+	mutex_unlock(&kvm->slots_lock);
+
+	return ret;
+}