int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
{
int i, ret;
ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
if (ret)
return ret;
for (i = 0; i < count; i++) {
/* Retry eagain maps */
if (map_ops[i].status == GNTST_eagain)
gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
&map_ops[i].status, __func__);
if (map_ops[i].status == GNTST_okay) {
struct xen_page_foreign *foreign;
SetPageForeign(pages[i]);
foreign = xen_page_foreign(pages[i]);
foreign->domid = map_ops[i].dom;
foreign->gref = map_ops[i].ref;
}
}
return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
}
struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
struct page *pte;
#ifdef CONFIG_HIGHPTE
pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
#else
pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
if (pte) {
SetPageForeign(pte, pte_free);
init_page_count(pte);
}
#endif
return pte;
}
/*
* Must not be called with IRQs off. This should only be used on the
* slow path.
*
* Copy a foreign granted page to local memory.
*/
int gnttab_copy_grant_page(grant_ref_t ref, struct page **pagep)
{
struct gnttab_unmap_and_replace unmap;
mmu_update_t mmu;
struct page *page;
struct page *new_page;
void *new_addr;
void *addr;
paddr_t pfn;
maddr_t mfn;
maddr_t new_mfn;
int err;
page = *pagep;
if (!get_page_unless_zero(page))
return -ENOENT;
err = -ENOMEM;
new_page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (!new_page)
goto out;
new_addr = page_address(new_page);
addr = page_address(page);
copy_page(new_addr, addr);
pfn = page_to_pfn(page);
mfn = pfn_to_mfn(pfn);
new_mfn = virt_to_mfn(new_addr);
write_seqlock_bh(&gnttab_dma_lock);
/* Make seq visible before checking page_mapped. */
smp_mb();
/* Has the page been DMA-mapped? */
if (unlikely(page_mapped(page))) {
write_sequnlock_bh(&gnttab_dma_lock);
put_page(new_page);
err = -EBUSY;
goto out;
}
if (!xen_feature(XENFEAT_auto_translated_physmap))
set_phys_to_machine(pfn, new_mfn);
gnttab_set_replace_op(&unmap, (unsigned long)addr,
(unsigned long)new_addr, ref);
err = HYPERVISOR_grant_table_op(GNTTABOP_unmap_and_replace,
&unmap, 1);
BUG_ON(err);
BUG_ON(unmap.status != GNTST_okay);
write_sequnlock_bh(&gnttab_dma_lock);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
set_phys_to_machine(page_to_pfn(new_page), INVALID_P2M_ENTRY);
mmu.ptr = (new_mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
mmu.val = pfn;
err = HYPERVISOR_mmu_update(&mmu, 1, NULL, DOMID_SELF);
BUG_ON(err);
}
new_page->mapping = page->mapping;
new_page->index = page->index;
set_bit(PG_foreign, &new_page->flags);
if (PageReserved(page))
SetPageReserved(new_page);
*pagep = new_page;
SetPageForeign(page, gnttab_page_free);
page->mapping = NULL;
out:
put_page(page);
return err;
}
