On 18/09/18 19:03, Boris Ostrovsky wrote:
> 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 <jgr...@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 ?
The loop is running until the end, so i == count for the call of kmap_ops().
Juergen
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
