linux/include/xen/interface
Jeremy Fitzhardinge e57778a1e3 xen: implement ptep_modify_prot_start/commit
Xen has a pte update function which will update a pte while preserving
its accessed and dirty bits.  This means that ptep_modify_prot_start() can be
implemented as a simple read of the pte value.  The hardware may
update the pte in the meantime, but ptep_modify_prot_commit() updates it while
preserving any changes that may have happened in the meantime.

The updates in ptep_modify_prot_commit() are batched if we're currently in lazy
mmu mode.

The mmu_update hypercall can take a batch of updates to perform, but
this code doesn't make particular use of that feature, in favour of
using generic multicall batching to get them all into the hypervisor.

The net effect of this is that each mprotect pte update turns from two
expensive trap-and-emulate faults into they hypervisor into a single
hypercall whose cost is amortized in a batched multicall.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25 15:17:23 +02:00
..
io xen pvfb: Dynamic mode support (screen resizing) 2008-05-27 10:11:36 +02:00
callback.h xen: add support for callbackops hypercall 2008-04-24 23:57:31 +02:00
elfnote.h xen: add new Xen elfnote types and use them appropriately 2008-06-02 13:25:51 +02:00
event_channel.h xen: Add Xen interface header files 2007-07-18 08:47:42 -07:00
features.h xen: implement ptep_modify_prot_start/commit 2008-06-25 15:17:23 +02:00
grant_table.h xen: add missing definitions for xen grant table which ia64/xen needs 2008-04-24 23:57:32 +02:00
memory.h xen: add missing definitions in include/xen/interface/memory.h which ia64/xen needs 2008-05-27 10:11:36 +02:00
physdev.h xen: Add Xen interface header files 2007-07-18 08:47:42 -07:00
sched.h xen: Add Xen interface header files 2007-07-18 08:47:42 -07:00
vcpu.h xen: add missing definitions in include/xen/interface/vcpu.h which ia64/xen needs 2008-04-24 23:57:32 +02:00
version.h xen: Add Xen interface header files 2007-07-18 08:47:42 -07:00
xen.h xen: implement ptep_modify_prot_start/commit 2008-06-25 15:17:23 +02:00
xencomm.h xen: import arch generic part of xencomm 2008-04-24 23:57:32 +02:00