Re: [Xen-devel] [PATCH] xen-netback: fix occasional leak of grant ref mappings under memory pressure

From: Andrew Cooper
Date: Thu Feb 28 2019 - 04:50:15 EST

On 28/02/2019 02:03, Igor Druzhinin wrote:
> Zero-copy callback flag is not yet set on frag list skb at the moment
> xenvif_handle_frag_list() returns -ENOMEM. This eventually results in
> leaking grant ref mappings since xenvif_zerocopy_callback() is never
> called for these fragments. Those eventually build up and cause Xen
> to kill Dom0 as the slots get reused for new mappings.

Its worth pointing out what (debug) Xen notices is dom0 performing
implicit grant unmap.