drivers/vfio: Support EEH error injection

The patch adds one more EEH sub-command (VFIO_EEH_PE_INJECT_ERR)
to inject the specified EEH error, which is represented by
(struct vfio_eeh_pe_err), to the indicated PE for testing purpose.

Signed-off-by: Gavin Shan <[e-mail]>
Reviewed-by: David Gibson <[e-mail]>
Acked-by: Alex Williamson <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>

Documentation/vfio.txt

···
 
 	....
 
+	/* Inject EEH error, which is expected to be caused by 32-bits
+	 * config load.
+	 */
+	pe_op.op = VFIO_EEH_PE_INJECT_ERR;
+	pe_op.err.type = EEH_ERR_TYPE_32;
+	pe_op.err.func = EEH_ERR_FUNC_LD_CFG_ADDR;
+	pe_op.err.addr = 0ul;
+	pe_op.err.mask = 0ul;
+	ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+	....
+
 	/* When 0xFF's returned from reading PCI config space or IO BARs
 	 * of the PCI device. Check the PE's state to see if that has been
 	 * frozen.

drivers/vfio/vfio_spapr_eeh.c

···
 		case VFIO_EEH_PE_CONFIGURE:
 			ret = eeh_pe_configure(pe);
 			break;
+		case VFIO_EEH_PE_INJECT_ERR:
+			minsz = offsetofend(struct vfio_eeh_pe_op, err.mask);
+			if (op.argsz < minsz)
+				return -EINVAL;
+			if (copy_from_user(&op, (void __user *)arg, minsz))
+				return -EFAULT;
+
+			ret = eeh_pe_inject_err(pe, op.err.type, op.err.func,
+						op.err.addr, op.err.mask);
+			break;
 		default:
 			ret = -EINVAL;
 		}

include/uapi/linux/vfio.h

···
  * - unfreeze IO/DMA for frozen PE;
  * - read PE state;
  * - reset PE;
- * - configure PE.
+ * - configure PE;
+ * - inject EEH error.
  */
+struct vfio_eeh_pe_err {
+	__u32 type;
+	__u32 func;
+	__u64 addr;
+	__u64 mask;
+};
+
 struct vfio_eeh_pe_op {
 	__u32 argsz;
 	__u32 flags;
 	__u32 op;
+	union {
+		struct vfio_eeh_pe_err err;
+	};
 };
 
 #define VFIO_EEH_PE_DISABLE		0	/* Disable EEH functionality */
···
 #define VFIO_EEH_PE_RESET_HOT		6	/* Assert hot reset          */
 #define VFIO_EEH_PE_RESET_FUNDAMENTAL	7	/* Assert fundamental reset  */
 #define VFIO_EEH_PE_CONFIGURE		8	/* PE configuration          */
+#define VFIO_EEH_PE_INJECT_ERR		9	/* Inject EEH error          */
 
 #define VFIO_EEH_PE_OP			_IO(VFIO_TYPE, VFIO_BASE + 21)