KVM: s390: pci: enable host forwarding of Adapter Event Notifications

In cases where interrupts are not forwarded to the guest via firmware,
KVM is responsible for ensuring delivery. When an interrupt presents
with the forwarding bit, we must process the forwarding tables until
all interrupts are delivered.

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>
Link: https://lore.kernel.org/r/20220606203325.110625-14-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

s390: add struct tpi_info to struct pt_regs

To avoid casting ptrace members, add a union containing
both struct tpi_info and explicit int_code/int_parm members.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/cio: add tpi.h header file

For future work we need the struct tpi_info declaration in asm/ptrace.h.
Due to circular dependencies it cannot stay in asm/lowcore.h or asm/cio.h,
which would be the preferred location. Therefore add it in its own header
file.

Also fix a typo in the length of a reserved field that did not have a
functional effect beyond an incorrect field value in the s390_cio_tpi
tracepoint.

Fixes: 2ab59de7c5ce ("s390/cio: Consolidate inline assemblies and related data definitions")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>