xen: introduce gnttab_map_refs and gnttab_unmap_refs

gnttab_map_refs maps some grant refs and uses the new m2p override to
set a proper m2p mapping for the granted pages.

gnttab_unmap_refs unmaps the granted refs and removes th mappings from
the m2p override.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Stefano Stabellini 2010-12-10 14:54:44 +00:00 committed by Konrad Rzeszutek Wilk
parent 9b705f0e98
commit 289b777eac
2 changed files with 41 additions and 0 deletions

View File

@ -447,6 +447,42 @@ unsigned int gnttab_max_grant_frames(void)
} }
EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
struct page **pages, unsigned int count)
{
int i, ret;
pte_t *pte;
unsigned long mfn;
ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
for (i = 0; i < count; i++) {
/* m2p override only supported for GNTMAP_contains_pte mappings */
if (!(map_ops[i].flags & GNTMAP_contains_pte))
continue;
pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
(map_ops[i].host_addr & ~PAGE_MASK));
mfn = pte_mfn(*pte);
m2p_add_override(mfn, pages[i]);
}
return ret;
}
EXPORT_SYMBOL_GPL(gnttab_map_refs);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct page **pages, unsigned int count)
{
int i, ret;
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
for (i = 0; i < count; i++)
m2p_remove_override(pages[i]);
return ret;
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
static int gnttab_map(unsigned int start_idx, unsigned int end_idx) static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
{ {
struct gnttab_setup_table setup; struct gnttab_setup_table setup;

View File

@ -155,4 +155,9 @@ unsigned int gnttab_max_grant_frames(void);
#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
struct page **pages, unsigned int count);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct page **pages, unsigned int count);
#endif /* __ASM_GNTTAB_H__ */ #endif /* __ASM_GNTTAB_H__ */