forked from luck/tmp_suning_uos_patched
xen-gntdev: Fix unmap notify on PV domains
In paravirtualized guests, the struct page* for mappings is only a placeholder, and cannot be used to access the granted memory. Use the userspace mapping that we have set up in order to implement UNMAP_NOTIFY_CLEAR_BYTE. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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0ea22f072f
@ -289,7 +289,12 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
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if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
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int pgno = (map->notify.addr >> PAGE_SHIFT);
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if (pgno >= offset && pgno < offset + pages) {
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if (pgno >= offset && pgno < offset + pages && use_ptemod) {
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void __user *tmp;
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tmp = map->vma->vm_start + map->notify.addr;
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copy_to_user(tmp, &err, 1);
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map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
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} else if (pgno >= offset && pgno < offset + pages) {
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uint8_t *tmp = kmap(map->pages[pgno]);
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tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
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kunmap(map->pages[pgno]);
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@ -298,7 +303,7 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
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}
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pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
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err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages, pages);
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err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages);
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if (err)
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return err;
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