Creating a dynamic address translation with translation exception qualifier

摘要

An enhanced dynamic address translation facility product is created such that, in one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. Dynamic address translation of the virtual address proceeds. In response to a translation interruption having occurred during dynamic address translation, bits are stored in a translation exception qualifier (TXQ) field to indicate that the exception was either a host DAT exception having occurred while running a host program or a host DAT exception having occurred while running a guest program. The TXQ is further capable of indicating that the exception was associated with a host virtual address derived from a guest page frame real address or a guest segment frame absolute address. The TXQ is further capable of indicating that a larger or smaller host frame size is preferred to back a guest frame.

主权项

1. A method for creating a computer program product for qualifying a translation exception in a dynamic address translation (DAT) facility configured to translate a program address of a block of virtual memory into a translated address of a desired block of host main storage in a computer system, the method comprising:
storing on a storage medium, readable by said computer system, instructions configured to cause the computer system to translate the program address into an address of a desired block of main storage; and storing on the storage medium, readable by said computer system, instructions configured to cause the computer system, based on a translation exception event having occurred during said translating of the program address, to store a translation exception qualifier (TXQ) to indicate whether the translation exception event relates to a host DAT exception or a guest DAT exception, said TXQ indicating with a first value that an exception was caused by a currently executing configuration, with a second value that the exception was associated with a host virtual address derived from a guest page frame real address, with a third value that the exception was associated with a host virtual address derived from a guest segment frame absolute address, and with a fourth value that the exception was associated with a host virtual address derived from a guest address other than a guest page frame real address or a guest segment frame absolute address.