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Commit 289b777e authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Konrad Rzeszutek Wilk
Browse files

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: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 9b705f0e

drivers/xen/grant-table.c

+36 −0
Original line number Diff line number Diff line
@@ -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;

include/xen/grant_table.h

+5 −0
Original line number Diff line number Diff line
@@ -155,4 +155,9 @@ unsigned int gnttab_max_grant_frames(void); 


#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__ */