Revert "vfio: Use capability chains to handle device specific irq"

virt inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I61SPO
CVE: NA

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

This reverts commit 41e3175a.
Signed-off-by: NKunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/uapi/linux/vfio.h

@@ -712,27 +712,11 @@ struct vfio_irq_info {
 #define VFIO_IRQ_INFO_MASKABLE		(1 << 1)
 #define VFIO_IRQ_INFO_AUTOMASKED	(1 << 2)
 #define VFIO_IRQ_INFO_NORESIZE		(1 << 3)
-#define VFIO_IRQ_INFO_FLAG_CAPS		(1 << 4) /* Info supports caps */
 	__u32	index;		/* IRQ index */
 	__u32	count;		/* Number of IRQs within this index */
-	__u32	cap_offset;	/* Offset within info struct of first cap */
 };
 #define VFIO_DEVICE_GET_IRQ_INFO	_IO(VFIO_TYPE, VFIO_BASE + 9)
 
-/*
- * The irq type capability allows IRQs unique to a specific device or
- * class of devices to be exposed.
- *
- * The structures below define version 1 of this capability.
- */
-#define VFIO_IRQ_INFO_CAP_TYPE      3
-
-struct vfio_irq_info_cap_type {
-	struct vfio_info_cap_header header;
-	__u32 type;     /* global per bus driver */
-	__u32 subtype;  /* type specific */
-};
-
 /**
  * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
  *
@@ -834,8 +818,7 @@ enum {
 	VFIO_PCI_MSIX_IRQ_INDEX,
 	VFIO_PCI_ERR_IRQ_INDEX,
 	VFIO_PCI_REQ_IRQ_INDEX,
-	VFIO_PCI_NUM_IRQS = 5	/* Fixed user ABI, IRQ indexes >=5 use   */
-				/* device specific cap to define content */
+	VFIO_PCI_NUM_IRQS
 };
 
 /*