diff options
Diffstat (limited to 'drivers/xen/grant-table.c')
| -rw-r--r-- | drivers/xen/grant-table.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 6c453181649..9ef54ebc119 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -447,6 +447,52 @@ unsigned int gnttab_max_grant_frames(void) } 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); + if (ret) + return ret; + + 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); + ret = m2p_add_override(mfn, pages[i]); + if (ret) + return ret; + } + + 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); + if (ret) + return ret; + + for (i = 0; i < count; i++) { + ret = m2p_remove_override(pages[i]); + if (ret) + return ret; + } + + return ret; +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs); + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; |