Commit 4d544e3b authored by Chang Huaixin's avatar Chang Huaixin Committed by Dmitry Torokhov

Input: xen-kbdfront - free grant table entry in xenkbd_disconnect_backend

xenkbd_disconnect_backend doesn't free grant table entry.  This bug affects
live migration.

xenkbd_disconnect_backend uses gnttab_end_foreign_access_ref to handle
grant table entry which doesn't really free an entry.

Thus every time we do xenkbd_resume, grant table entry increses by one. As
an grant table entry occupies 8 bytes, an grant table page has at most 512
entries. Every 512 times we do xenkdb_resume, grant table pages increses by
one.

After around 3500 times of live migration, grant table pages will increase
by 7, causing too many pages to populate and hitting max_pages limit when
assigning pages.Thus assign_pages will fail, so will live migration.
Signed-off-by: default avatarChang Huaixin <huaixin.chx@alibaba-inc.com>
Acked-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent b0cfb794
...@@ -285,7 +285,7 @@ static int xenkbd_connect_backend(struct xenbus_device *dev, ...@@ -285,7 +285,7 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
error_evtchan: error_evtchan:
xenbus_free_evtchn(dev, evtchn); xenbus_free_evtchn(dev, evtchn);
error_grant: error_grant:
gnttab_end_foreign_access_ref(info->gref, 0); gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1; info->gref = -1;
return ret; return ret;
} }
...@@ -296,7 +296,7 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *info) ...@@ -296,7 +296,7 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *info)
unbind_from_irqhandler(info->irq, info); unbind_from_irqhandler(info->irq, info);
info->irq = -1; info->irq = -1;
if (info->gref >= 0) if (info->gref >= 0)
gnttab_end_foreign_access_ref(info->gref, 0); gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1; info->gref = -1;
} }
......
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