Messages in this thread | | | Subject | Re: [PATCH] xen: issue warning message when out of grant maptrack entries | From | Boris Ostrovsky <> | Date | Tue, 18 Sep 2018 13:03:14 -0400 |
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On 9/18/18 5:32 AM, Juergen Gross wrote: > When a driver domain (e.g. dom0) is running out of maptrack entries it > can't map any more foreign domain pages. Instead of silently stalling > the affected domUs issue a rate limited warning in this case in order > to make it easier to detect that situation. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > drivers/xen/grant-table.c | 25 +++++++++++++++++++------ > 1 file changed, 19 insertions(+), 6 deletions(-) > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 7bafa703a992..09f6ff8c1957 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -1040,18 +1040,31 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, > 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) { > + switch (map_ops[i].status) { > + case 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; > + break; > + } > + > + case GNTST_no_device_space: > + pr_warn_ratelimited("maptrack limit reached, can't map all guest pages\n"); > + break; > + > + case GNTST_eagain: > + /* Retry eagain maps */ > + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, > + map_ops + i, > + &map_ops[i].status, __func__); > + break; > + > + default: > + break; > } > }
Should we pass 'i' instead of count to set_foreign_p2m_mapping() below? The loop there will skip entries that are in error, but does it make sense to do the hypercall for kmap_ops with count>i ?
-boris
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