kvm VM ioctl操作

VM虚拟机提供的文件操作，主要以ioctl方式提供：

static struct file_operations kvm_vm_fops = {
.release        = kvm_vm_release,
.unlocked_ioctl = kvm_vm_ioctl,
 #ifdef CONFIG_KVM_COMPAT
.compat_ioctl   = kvm_vm_compat_ioctl,
 #endif
.llseek  = noop_llseek,
 };
 static long kvm_vm_ioctl(struct file *filp,   unsigned int ioctl, unsigned long arg)
 {
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
int r;


if (kvm->mm != current->mm)
return -EIO;
switch (ioctl) {
case KVM_CREATE_VCPU:
r = kvm_vm_ioctl_create_vcpu(kvm, arg);
break;
case KVM_SET_USER_MEMORY_REGION: {
struct kvm_userspace_memory_region kvm_userspace_mem;


r = -EFAULT;
if (copy_from_user(&kvm_userspace_mem, argp,
sizeof(kvm_userspace_mem)))
goto out;


r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
break;
}
case KVM_GET_DIRTY_LOG: {
struct kvm_dirty_log log;


r = -EFAULT;
if (copy_from_user(&log, argp, sizeof(log)))
goto out;
r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
break;
}
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
case KVM_REGISTER_COALESCED_MMIO: {
struct kvm_coalesced_mmio_zone zone;


r = -EFAULT;
if (copy_from_user(&zone, argp, sizeof(zone)))
goto out;
r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
break;
}
case KVM_UNREGISTER_COALESCED_MMIO: {
struct kvm_coalesced_mmio_zone zone;


r = -EFAULT;
if (copy_from_user(&zone, argp, sizeof(zone)))
goto out;
r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
break;
}
 #endif
case KVM_IRQFD: {
struct kvm_irqfd data;


r = -EFAULT;
if (copy_from_user(&data, argp, sizeof(data)))
goto out;
r = kvm_irqfd(kvm, &data);
break;
}
case KVM_IOEVENTFD: {
struct kvm_ioeventfd data;


r = -EFAULT;
if (copy_from_user(&data, argp, sizeof(data)))
goto out;
r = kvm_ioeventfd(kvm, &data);
break;
}
 #ifdef CONFIG_HAVE_KVM_MSI
case KVM_SIGNAL_MSI: {
struct kvm_msi msi;


r = -EFAULT;
if (copy_from_user(&msi, argp, sizeof(msi)))
goto out;
r = kvm_send_userspace_msi(kvm, &msi);
break;
}
 #endif
 #ifdef __KVM_HAVE_IRQ_LINE
case KVM_IRQ_LINE_STATUS:
case KVM_IRQ_LINE: {
struct kvm_irq_level irq_event;


r = -EFAULT;
if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
goto out;


r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
ioctl == KVM_IRQ_LINE_STATUS);
if (r)
goto out;


r = -EFAULT;
if (ioctl == KVM_IRQ_LINE_STATUS) {
if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
goto out;
}


r = 0;
break;
}
 #endif
 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
case KVM_SET_GSI_ROUTING: {
struct kvm_irq_routing routing;
struct kvm_irq_routing __user *urouting;
struct kvm_irq_routing_entry *entries = NULL;


r = -EFAULT;
if (copy_from_user(&routing, argp, sizeof(routing)))
goto out;
r = -EINVAL;
if (routing.nr > KVM_MAX_IRQ_ROUTES)
goto out;
if (routing.flags)
goto out;
if (routing.nr) {
r = -ENOMEM;
entries = vmalloc(routing.nr * sizeof(*entries));
if (!entries)
goto out;
r = -EFAULT;
urouting = argp;
if (copy_from_user(entries, urouting->entries,
  routing.nr * sizeof(*entries)))
goto out_free_irq_routing;
}
r = kvm_set_irq_routing(kvm, entries, routing.nr,
routing.flags);
 out_free_irq_routing:
vfree(entries);
break;
}
 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
case KVM_CREATE_DEVICE: {
struct kvm_create_device cd;


r = -EFAULT;
if (copy_from_user(&cd, argp, sizeof(cd)))
goto out;


r = kvm_ioctl_create_device(kvm, &cd);
if (r)
goto out;


r = -EFAULT;
if (copy_to_user(argp, &cd, sizeof(cd)))
goto out;


r = 0;
break;
}
case KVM_CHECK_EXTENSION:
r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
break;
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
 out:
return r;
 }

#define KVM_CREATE_VCPU           _IO(KVMIO,   0x41)
 #define KVM_GET_DIRTY_LOG         _IOW(KVMIO,  0x42, struct kvm_dirty_log)
 /* KVM_SET_MEMORY_ALIAS is obsolete: */
 #define KVM_SET_MEMORY_ALIAS      _IOW(KVMIO,  0x43, struct kvm_memory_alias)
 #define KVM_SET_NR_MMU_PAGES      _IO(KVMIO,   0x44)
 #define KVM_GET_NR_MMU_PAGES      _IO(KVMIO,   0x45)
 #define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46, struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
 #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO,  0x48, __u64)