Note: in this version, all IOMMU changes have been removed to be pursued as a follow-on / in conjunction with IOMMUFD. This series proposes to add only exploitation of the interpretive execution facilities. Enable interpretive execution of zPCI instructions + adapter interruption forwarding for s390x KVM vfio-pci. This is done by triggering a routine when the VFIO group is associated with the KVM guest, transmitting to firmware a special token (GISA designation) to enable that specific guest for interpretive execution on that zPCI device. Load/store interpreation enablement is then controlled by userspace (based upon whether or not a SHM bit is placed in the virtual function handle). Adapter Event Notification interpretation is controlled from userspace via a new KVM ioctl. By allowing intepretation of zPCI instructions and firmware delivery of interrupts to guests, we can reduce the frequency of guest SIE exits for zPCI.
