vfio-pci/zdev: different maxstbl for interpreted devices

When doing load/store interpretation, the maximum store block length is
determined by the underlying firmware, not the host kernel API. Reflect
that in the associated Query PCI Function Group clp capability and let
userspace decide which is appropriate to present to the guest.

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/20220606203325.110625-20-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

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>

vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO

Allow the VFIO_DEVICE_GET_INFO ioctl to include a capability chain.
Add a flag indicating capability chain support, and introduce the
definitions for the first set of capabilities which are specified to
s390 zPCI devices.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>