xen: Add xen_create_contiguous_region

A memory region must be physically contiguous in order to be accessed
through DMA.  This patch adds xen_create_contiguous_region, which
ensures a region of contiguous virtual memory is also physically
contiguous.

Based on Stephen Tweedie's port of the 2.6.18-xen version.

Remove contiguous_bitmap[] as it's no longer needed.

Ported from linux-2.6.18-xen.hg 707:e410857fd83c

[ Impact: add Xen-internal API to make pages phys-contig ]

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Alex Nixon 2009-02-09 12:05:46 -08:00 committed by Konrad Rzeszutek Wilk
parent 19001c8c5b
commit 08bbc9da92
3 changed files with 249 additions and 0 deletions

View file

@ -54,6 +54,48 @@ struct xen_memory_reservation {
};
DEFINE_GUEST_HANDLE_STRUCT(xen_memory_reservation);
/*
* An atomic exchange of memory pages. If return code is zero then
* @out.extent_list provides GMFNs of the newly-allocated memory.
* Returns zero on complete success, otherwise a negative error code.
* On complete success then always @nr_exchanged == @in.nr_extents.
* On partial success @nr_exchanged indicates how much work was done.
*/
#define XENMEM_exchange 11
struct xen_memory_exchange {
/*
* [IN] Details of memory extents to be exchanged (GMFN bases).
* Note that @in.address_bits is ignored and unused.
*/
struct xen_memory_reservation in;
/*
* [IN/OUT] Details of new memory extents.
* We require that:
* 1. @in.domid == @out.domid
* 2. @in.nr_extents << @in.extent_order ==
* @out.nr_extents << @out.extent_order
* 3. @in.extent_start and @out.extent_start lists must not overlap
* 4. @out.extent_start lists GPFN bases to be populated
* 5. @out.extent_start is overwritten with allocated GMFN bases
*/
struct xen_memory_reservation out;
/*
* [OUT] Number of input extents that were successfully exchanged:
* 1. The first @nr_exchanged input extents were successfully
* deallocated.
* 2. The corresponding first entries in the output extent list correctly
* indicate the GMFNs that were successfully exchanged.
* 3. All other input and output extents are untouched.
* 4. If not all input exents are exchanged then the return code of this
* command will be non-zero.
* 5. THIS FIELD MUST BE INITIALISED TO ZERO BY THE CALLER!
*/
unsigned long nr_exchanged;
};
DEFINE_GUEST_HANDLE_STRUCT(xen_memory_exchange);
/*
* Returns the maximum machine frame number of mapped RAM in this system.
* This command always succeeds (it never returns an error code).