KVM: support device deassignment

Support device deassignment, it can be used in device hotplug.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c92b63462b79..3238e08e4651 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -530,6 +530,35 @@ out_free:
 }
 #endif
 
+#ifdef KVM_CAP_DEVICE_DEASSIGNMENT
+static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
+                struct kvm_assigned_pci_dev *assigned_dev)
+{
+        int r = 0;
+        struct kvm_assigned_dev_kernel *match;
+
+        mutex_lock(&kvm->lock);
+
+        match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+                                      assigned_dev->assigned_dev_id);
+        if (!match) {
+                printk(KERN_INFO "%s: device hasn't been assigned before, "
+                  "so cannot be deassigned\n", __func__);
+                r = -EINVAL;
+                goto out;
+        }
+
+        if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU)
+                kvm_deassign_device(kvm, match);
+
+        kvm_free_assigned_device(kvm, match);
+
+out:
+        mutex_unlock(&kvm->lock);
+        return r;
+}
+#endif
+
 static inline int valid_vcpu(int n)
 {
         return likely(n >= 0 && n < KVM_MAX_VCPUS);
@@ -1863,6 +1892,19 @@ static long kvm_vm_ioctl(struct file *filp,
                 break;
         }
 #endif
+#ifdef KVM_CAP_DEVICE_DEASSIGNMENT
+        case KVM_DEASSIGN_PCI_DEVICE: {
+                struct kvm_assigned_pci_dev assigned_dev;
+
+                r = -EFAULT;
+                if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
+                        goto out;
+                r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
+                if (r)
+                        goto out;
+                break;
+        }
+#endif
         default:
                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
         }