vfio-pci/zdev: add function handle to clp base capability

The function handle is a system-wide unique identifier for a zPCI
device.  With zPCI instruction interpretation, the host will no
longer be executing the zPCI instructions on behalf of the guest.
As a result, the guest needs to use the real function handle in
order for firmware to associate the instruction with the proper
PCI function.  Let's provide that handle to the guest.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20220606203325.110625-19-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

drivers/vfio/pci/vfio_pci_zdev.c

@@ -24,14 +24,15 @@ static int zpci_base_cap(struct zpci_dev *zdev, struct vfio_info_cap *caps)
 {
 	struct vfio_device_info_cap_zpci_base cap = {
 		.header.id = VFIO_DEVICE_INFO_CAP_ZPCI_BASE,
-		.header.version = 1,
+		.header.version = 2,
 		.start_dma = zdev->start_dma,
 		.end_dma = zdev->end_dma,
 		.pchid = zdev->pchid,
 		.vfn = zdev->vfn,
 		.fmb_length = zdev->fmb_length,
 		.pft = zdev->pft,
-		.gid = zdev->pfgid
+		.gid = zdev->pfgid,
+		.fh = zdev->fh
 	};
 
 	return vfio_info_add_capability(caps, &cap.header, sizeof(cap));

include/uapi/linux/vfio_zdev.h

@@ -29,6 +29,9 @@ struct vfio_device_info_cap_zpci_base {
 	__u16 fmb_length;	/* Measurement Block Length (in bytes) */
 	__u8 pft;		/* PCI Function Type */
 	__u8 gid;		/* PCI function group ID */
+	/* End of version 1 */
+	__u32 fh;		/* PCI function handle */
+	/* End of version 2 */
 };
 
 /**