On 03/02/2016 00:51, Tamas K Lengyel wrote:
Can anyone point me to which change or what may be causing this?Hello all,with the latest master branch of Xen there is a regression enabling vm_event on a domain. If an event listener was previously active on the domain it is now not possible to reenable events as the domctl returns -EINVAL. The problem seems to stem from activating the magic page for vm_event using prepare_ring_for_helper as it returns NULL. Further looking into where things go wrong within that function it seems the page type returned by __get_gfn_type_access is p2m_ram_logdirty with an invalid mfn (0xffffffffffffffff) and then it hits "Error path: not a suitable GFN at all".
Did the previous event listener replace the page it stole from guest physmap for ring purposes when it exited?