Re: [Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-20 Thread Tamas K Lengyel
On Oct 20, 2016 18:40, "George Dunlap" wrote: > > On 20/10/16 17:29, Tamas K Lengyel wrote: > > On Oct 20, 2016 18:18, "George Dunlap" wrote: > >> > >> On 14/10/16 01:00, Tamas K Lengyel wrote: > >>> Attempting to change gfn mappings with

Re: [Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-20 Thread George Dunlap
On 20/10/16 17:29, Tamas K Lengyel wrote: > On Oct 20, 2016 18:18, "George Dunlap" wrote: >> >> On 14/10/16 01:00, Tamas K Lengyel wrote: >>> Attempting to change gfn mappings with altp2m on a memory shared page > results >>> in a lock-order violation (mm locking order

Re: [Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-20 Thread Tamas K Lengyel
On Oct 20, 2016 18:18, "George Dunlap" wrote: > > On 14/10/16 01:00, Tamas K Lengyel wrote: > > Attempting to change gfn mappings with altp2m on a memory shared page results > > in a lock-order violation (mm locking order violation: 282 > 254), which > > crashes the

Re: [Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-20 Thread Wei Liu
On Thu, Oct 20, 2016 at 05:18:36PM +0100, George Dunlap wrote: > On 14/10/16 01:00, Tamas K Lengyel wrote: > > Attempting to change gfn mappings with altp2m on a memory shared page > > results > > in a lock-order violation (mm locking order violation: 282 > 254), which > > crashes the hypervisor.

Re: [Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-20 Thread George Dunlap
On 14/10/16 01:00, Tamas K Lengyel wrote: > Attempting to change gfn mappings with altp2m on a memory shared page results > in a lock-order violation (mm locking order violation: 282 > 254), which > crashes the hypervisor. Don't attempt to automatically unshare such pages and > just fall back to

[Xen-devel] [PATCH for-4.8] altp2m: don't attempt to unshare pages during change_altp2m_gfn op

2016-10-13 Thread Tamas K Lengyel
Attempting to change gfn mappings with altp2m on a memory shared page results in a lock-order violation (mm locking order violation: 282 > 254), which crashes the hypervisor. Don't attempt to automatically unshare such pages and just fall back to failing the op if the page type is not correct.