Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-06-22 Thread Andrew Cooper
On 22/06/2017 09:23, Marek Marczykowski-Górecki wrote: > [resurrecting old thread...] > > On Mon, Jan 16, 2017 at 11:41:55PM +, Andrew Cooper wrote: >> On 16/01/2017 23:06, Marek Marczykowski-Górecki wrote: >>> On Mon, Jan 16, 2017 at 05:17:59AM -0700, Jan Beulich wrote: 2) When the guest

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-06-22 Thread Marek Marczykowski-Górecki
[resurrecting old thread...] On Mon, Jan 16, 2017 at 11:41:55PM +, Andrew Cooper wrote: > On 16/01/2017 23:06, Marek Marczykowski-Górecki wrote: > > On Mon, Jan 16, 2017 at 05:17:59AM -0700, Jan Beulich wrote: > >> 2) When the guest issues stac()/clac(), it indicates to Xen _its own_ > >> inte

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-16 Thread Andrew Cooper
On 16/01/2017 23:06, Marek Marczykowski-Górecki wrote: > On Mon, Jan 16, 2017 at 05:17:59AM -0700, Jan Beulich wrote: > On 14.01.17 at 03:52, wrote: >>> On Sat, Jan 14, 2017 at 01:47:49AM +, Andrew Cooper wrote: In a native situation, SMAP raises #PF if hardware tries to follow a

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-16 Thread Marek Marczykowski-Górecki
On Mon, Jan 16, 2017 at 05:17:59AM -0700, Jan Beulich wrote: > >>> On 14.01.17 at 03:52, wrote: > > On Sat, Jan 14, 2017 at 01:47:49AM +, Andrew Cooper wrote: > >> In a native situation, SMAP raises #PF if hardware tries to follow a > >> user pointer outside of an area whitelisted by the kerne

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-16 Thread Jan Beulich
>>> On 14.01.17 at 03:52, wrote: > On Sat, Jan 14, 2017 at 01:47:49AM +, Andrew Cooper wrote: >> In a native situation, SMAP raises #PF if hardware tries to follow a >> user pointer outside of an area whitelisted by the kernel. (The >> copy_*_guest path suppresses #PF, opting instead to retur

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Sat, Jan 14, 2017 at 01:47:49AM +, Andrew Cooper wrote: > On 13/01/2017 20:32, Marek Marczykowski-Górecki wrote: > > On Fri, Jan 13, 2017 at 07:54:01PM +, Andrew Cooper wrote: > >> This is a guest kernel bug. The guest kernel has used SMAP to say > >> "please disallow all userspace acce

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/2017 20:32, Marek Marczykowski-Górecki wrote: > On Fri, Jan 13, 2017 at 07:54:01PM +, Andrew Cooper wrote: >> On 13/01/17 19:40, Marek Marczykowski-Górecki wrote: >>> On Fri, Jan 13, 2017 at 07:27:20PM +, Andrew Cooper wrote: On 13/01/17 18:59, Marek Marczykowski-Górecki wrote

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Fri, Jan 13, 2017 at 07:54:01PM +, Andrew Cooper wrote: > On 13/01/17 19:40, Marek Marczykowski-Górecki wrote: > > On Fri, Jan 13, 2017 at 07:27:20PM +, Andrew Cooper wrote: > >> On 13/01/17 18:59, Marek Marczykowski-Górecki wrote: > >>> On Fri, Jan 13, 2017 at 06:37:06PM +, Andrew C

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/17 19:40, Marek Marczykowski-Górecki wrote: > On Fri, Jan 13, 2017 at 07:27:20PM +, Andrew Cooper wrote: >> On 13/01/17 18:59, Marek Marczykowski-Górecki wrote: >>> On Fri, Jan 13, 2017 at 06:37:06PM +, Andrew Cooper wrote: On 13/01/17 18:32, Marek Marczykowski-Górecki wrote:

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Fri, Jan 13, 2017 at 07:27:20PM +, Andrew Cooper wrote: > On 13/01/17 18:59, Marek Marczykowski-Górecki wrote: > > On Fri, Jan 13, 2017 at 06:37:06PM +, Andrew Cooper wrote: > >> On 13/01/17 18:32, Marek Marczykowski-Górecki wrote: > >>> On Fri, Jan 13, 2017 at 06:15:35PM +, Andrew C

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/17 18:59, Marek Marczykowski-Górecki wrote: > On Fri, Jan 13, 2017 at 06:37:06PM +, Andrew Cooper wrote: >> On 13/01/17 18:32, Marek Marczykowski-Górecki wrote: >>> On Fri, Jan 13, 2017 at 06:15:35PM +, Andrew Cooper wrote: Can you get the result of this piece of debugging in

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Fri, Jan 13, 2017 at 06:37:06PM +, Andrew Cooper wrote: > On 13/01/17 18:32, Marek Marczykowski-Górecki wrote: > > On Fri, Jan 13, 2017 at 06:15:35PM +, Andrew Cooper wrote: > >> Can you get the result of this piece of debugging in the failure case? > > I've got this: > > ** d4v0 CFG(24,

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/17 18:32, Marek Marczykowski-Górecki wrote: > On Fri, Jan 13, 2017 at 06:15:35PM +, Andrew Cooper wrote: >> On 13/01/17 18:03, Marek Marczykowski-Górecki wrote: >>> On Fri, Jan 13, 2017 at 05:38:42PM +, Andrew Cooper wrote: On 13/01/17 17:31, Marek Marczykowski-Górecki wrote:

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Fri, Jan 13, 2017 at 06:15:35PM +, Andrew Cooper wrote: > On 13/01/17 18:03, Marek Marczykowski-Górecki wrote: > > On Fri, Jan 13, 2017 at 05:38:42PM +, Andrew Cooper wrote: > >> On 13/01/17 17:31, Marek Marczykowski-Górecki wrote: > >>> Hi, > >>> > >>> I have a strange problem - xc_evtc

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/17 18:03, Marek Marczykowski-Górecki wrote: > On Fri, Jan 13, 2017 at 05:38:42PM +, Andrew Cooper wrote: >> On 13/01/17 17:31, Marek Marczykowski-Górecki wrote: >>> Hi, >>> >>> I have a strange problem - xc_evtchn_status fails when running in HVM, >>> while exactly the same code (same

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
On Fri, Jan 13, 2017 at 05:38:42PM +, Andrew Cooper wrote: > On 13/01/17 17:31, Marek Marczykowski-Górecki wrote: > > Hi, > > > > I have a strange problem - xc_evtchn_status fails when running in HVM, > > while exactly the same code (same kernel, same application etc) works > > fine in PV. I've

Re: [Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Andrew Cooper
On 13/01/17 17:31, Marek Marczykowski-Górecki wrote: > Hi, > > I have a strange problem - xc_evtchn_status fails when running in HVM, > while exactly the same code (same kernel, same application etc) works > fine in PV. I've narrowed it down to copy_from_guest call in > common/event_channel.c, but

[Xen-devel] xc_evtchn_status fails with EFAULT on HVM, the same on PV works

2017-01-13 Thread Marek Marczykowski-Górecki
Hi, I have a strange problem - xc_evtchn_status fails when running in HVM, while exactly the same code (same kernel, same application etc) works fine in PV. I've narrowed it down to copy_from_guest call in common/event_channel.c, but no idea why it fails there. Xen version is 4.8.0. kernel is kern