Quelle  vgic-irqfd.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2015, 2016 ARM Ltd.
 */

#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <trace/events/kvm.h>
#include <kvm/arm_vgic.h>
#include "vgic.h"

/*
 * vgic_irqfd_set_irq: inject the IRQ corresponding to the
 * irqchip routing entry
 *
 * This is the entry point for irqfd IRQ injection
 */
static int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e,
   struct kvm *kvm, int irq_source_id,
   int level, bool line_status)
{
 unsigned int spi_id = e->irqchip.pin + VGIC_NR_PRIVATE_IRQS;

 if (!vgic_valid_spi(kvm, spi_id))
  return -EINVAL;
 return kvm_vgic_inject_irq(kvm, NULL, spi_id, level, NULL);
}

/**
 * kvm_set_routing_entry: populate a kvm routing entry
 * from a user routing entry
 *
 * @kvm: the VM this entry is applied to
 * @e: kvm kernel routing entry handle
 * @ue: user api routing entry handle
 * return 0 on success, -EINVAL on errors.
 */
int kvm_set_routing_entry(struct kvm *kvm,
     struct kvm_kernel_irq_routing_entry *e,
     const struct kvm_irq_routing_entry *ue)
{
 int r = -EINVAL;

 switch (ue->type) {
 case KVM_IRQ_ROUTING_IRQCHIP:
  e->set = vgic_irqfd_set_irq;
  e->irqchip.irqchip = ue->u.irqchip.irqchip;
  e->irqchip.pin = ue->u.irqchip.pin;
  if ((e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS) ||
      (e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
   goto out;
  break;
 case KVM_IRQ_ROUTING_MSI:
  e->set = kvm_set_msi;
  e->msi.address_lo = ue->u.msi.address_lo;
  e->msi.address_hi = ue->u.msi.address_hi;
  e->msi.data = ue->u.msi.data;
  e->msi.flags = ue->flags;
  e->msi.devid = ue->u.msi.devid;
  break;
 default:
  goto out;
 }
 r = 0;
out:
 return r;
}

static void kvm_populate_msi(struct kvm_kernel_irq_routing_entry *e,
        struct kvm_msi *msi)
{
 msi->address_lo = e->msi.address_lo;
 msi->address_hi = e->msi.address_hi;
 msi->data = e->msi.data;
 msi->flags = e->msi.flags;
 msi->devid = e->msi.devid;
}

/*
 * kvm_set_msi: inject the MSI corresponding to the
 * MSI routing entry
 *
 * This is the entry point for irqfd MSI injection
 * and userspace MSI injection.
 */
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
  struct kvm *kvm, int irq_source_id,
  int level, bool line_status)
{
 struct kvm_msi msi;

 if (!vgic_has_its(kvm))
  return -ENODEV;

 if (!level)
  return -1;

 kvm_populate_msi(e, &msi);
 return vgic_its_inject_msi(kvm, &msi);
}

/*
 * kvm_arch_set_irq_inatomic: fast-path for irqfd injection
 */
int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
         struct kvm *kvm, int irq_source_id, int level,
         bool line_status)
{
 if (!level)
  return -EWOULDBLOCK;

 switch (e->type) {
 case KVM_IRQ_ROUTING_MSI: {
  struct kvm_msi msi;

  if (!vgic_has_its(kvm))
   break;

  kvm_populate_msi(e, &msi);
  return vgic_its_inject_cached_translation(kvm, &msi);
 }

 case KVM_IRQ_ROUTING_IRQCHIP:
  /*
 * Injecting SPIs is always possible in atomic context
 * as long as the damn vgic is initialized.
 */
  if (unlikely(!vgic_initialized(kvm)))
   break;
  return vgic_irqfd_set_irq(e, kvm, irq_source_id, 1, line_status);
 }

 return -EWOULDBLOCK;
}

int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)
{
 struct kvm_irq_routing_entry *entries;
 struct vgic_dist *dist = &kvm->arch.vgic;
 u32 nr = dist->nr_spis;
 int i, ret;

 entries = kcalloc(nr, sizeof(*entries), GFP_KERNEL_ACCOUNT);
 if (!entries)
  return -ENOMEM;

 for (i = 0; i < nr; i++) {
  entries[i].gsi = i;
  entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
  entries[i].u.irqchip.irqchip = 0;
  entries[i].u.irqchip.pin = i;
 }
 ret = kvm_set_irq_routing(kvm, entries, nr, 0);
 kfree(entries);
 return ret;
}