diff --git a/libc/kernel/uapi/xen/privcmd.h b/libc/kernel/uapi/xen/privcmd.h
index 21d9f84..c4de85e 100644
--- a/libc/kernel/uapi/xen/privcmd.h
+++ b/libc/kernel/uapi/xen/privcmd.h
@@ -67,6 +67,15 @@
   __u64 num;
   __u64 addr;
 };
+#define PRIVCMD_IRQFD_FLAG_DEASSIGN (1 << 0)
+struct privcmd_irqfd {
+  void  * dm_op;
+  __u32 size;
+  __u32 fd;
+  __u32 flags;
+  domid_t dom;
+  __u8 pad[2];
+};
 #define IOCTL_PRIVCMD_HYPERCALL _IOC(_IOC_NONE, 'P', 0, sizeof(struct privcmd_hypercall))
 #define IOCTL_PRIVCMD_MMAP _IOC(_IOC_NONE, 'P', 2, sizeof(struct privcmd_mmap))
 #define IOCTL_PRIVCMD_MMAPBATCH _IOC(_IOC_NONE, 'P', 3, sizeof(struct privcmd_mmapbatch))
@@ -74,4 +83,5 @@
 #define IOCTL_PRIVCMD_DM_OP _IOC(_IOC_NONE, 'P', 5, sizeof(struct privcmd_dm_op))
 #define IOCTL_PRIVCMD_RESTRICT _IOC(_IOC_NONE, 'P', 6, sizeof(domid_t))
 #define IOCTL_PRIVCMD_MMAP_RESOURCE _IOC(_IOC_NONE, 'P', 7, sizeof(struct privcmd_mmap_resource))
+#define IOCTL_PRIVCMD_IRQFD _IOC(_IOC_NONE, 'P', 8, sizeof(struct privcmd_irqfd))
 #endif