linux/arch/s390/include/asm/page-states.h
Martin Schwidefsky c9b5ad546e s390/mm: tag normal pages vs pages used in page tables
The ESSA instruction has a new option that allows to tag pages that
are not used as a page table. Without the tag the hypervisor has to
assume that any guest page could be used in a page table inside the
guest. This forces the hypervisor to flush all guest TLB entries
whenever a host page table entry is invalidated. With the tag
the host can skip the TLB flush if the page is tagged as normal page.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-25 06:55:28 +02:00

21 lines
453 B
C

/*
* Copyright IBM Corp. 2017
* Author(s): Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
*/
#ifndef PAGE_STATES_H
#define PAGE_STATES_H
#define ESSA_GET_STATE 0
#define ESSA_SET_STABLE 1
#define ESSA_SET_UNUSED 2
#define ESSA_SET_VOLATILE 3
#define ESSA_SET_POT_VOLATILE 4
#define ESSA_SET_STABLE_RESIDENT 5
#define ESSA_SET_STABLE_IF_RESIDENT 6
#define ESSA_SET_STABLE_NODAT 7
#define ESSA_MAX ESSA_SET_STABLE_IF_RESIDENT
#endif