From 289b777eac19c811b474593b4d2fd14e46340c23 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 10 Dec 2010 14:54:44 +0000 Subject: 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 Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/grant-table.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'drivers/xen/grant-table.c') diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 6c4531816496..1afd5690858c 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -447,6 +447,42 @@ 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); + + 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) { struct gnttab_setup_table setup; -- cgit v1.2.2