vfio: Add new IRQ for DMA fault reporting

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I401IF
CVE: NA

------------------------------

Add a new IRQ type/subtype to get notification on nested
stage DMA faults.
Signed-off-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: Kunkun Jiang<jiangkunkun@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/uapi/linux/vfio.h

@@ -733,6 +733,9 @@ struct vfio_irq_info_cap_type {
 	__u32 subtype;  /* type specific */
 };
 
+#define VFIO_IRQ_TYPE_NESTED				(1)
+#define VFIO_IRQ_SUBTYPE_DMA_FAULT			(1)
+
 /**
  * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
  *