2013-03-01 12:16:16

by Josh Boyer

[permalink] [raw]
Subject: Re: [PATCH] mm/x86: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

On Thu, Feb 28, 2013 at 04:52:20PM -0800, H. Peter Anvin wrote:
> On 02/28/2013 04:42 PM, Josh Boyer wrote:
> > On Fri, Mar 01, 2013 at 01:36:29AM +0100, Borislav Petkov wrote:
> >> On Thu, Feb 28, 2013 at 04:15:45PM -0800, H. Peter Anvin wrote:
> >>>> I'll try to get someone to test this tomorrow.
> >>
> >> Btw, you'd need to apply that other patch too
> >>
> >> http://marc.info/?l=xen-devel&m=136206183814547&w=2
> >>
> >> so that arch_flush_lazy_mmu_mode() has at least one caller on x86_64.
> >
> > Yeah, we already have that applied. It stops crashes in xen
> > environments so we pulled it in as a bugfix. Thanks though!
> >
>
> Who are "we"?

Sorry, Fedora. That patch has a link to a bug in it. We applied the
patch for that bug. I'll apply Boris' patch on top and get the same
people to test it.

josh


2013-03-13 13:26:09

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH] mm/x86: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

On 03/01/2013 07:14 AM, Josh Boyer wrote:
> On Thu, Feb 28, 2013 at 04:52:20PM -0800, H. Peter Anvin wrote:
>> On 02/28/2013 04:42 PM, Josh Boyer wrote:
>>> On Fri, Mar 01, 2013 at 01:36:29AM +0100, Borislav Petkov wrote:
>>>> On Thu, Feb 28, 2013 at 04:15:45PM -0800, H. Peter Anvin wrote:
>>>>>> I'll try to get someone to test this tomorrow.
>>>> Btw, you'd need to apply that other patch too
>>>>
>>>> http://marc.info/?l=xen-devel&m=136206183814547&w=2
>>>>
>>>> so that arch_flush_lazy_mmu_mode() has at least one caller on x86_64.
>>> Yeah, we already have that applied. It stops crashes in xen
>>> environments so we pulled it in as a bugfix. Thanks though!
>>>
>> Who are "we"?
> Sorry, Fedora. That patch has a link to a bug in it. We applied the
> patch for that bug. I'll apply Boris' patch on top and get the same
> people to test it.

Josh, have you had a chance to test this?

-boris

2013-03-13 13:45:19

by Josh Boyer

[permalink] [raw]
Subject: Re: [PATCH] mm/x86: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

On Wed, Mar 13, 2013 at 09:25:44AM -0400, Boris Ostrovsky wrote:
> On 03/01/2013 07:14 AM, Josh Boyer wrote:
> >On Thu, Feb 28, 2013 at 04:52:20PM -0800, H. Peter Anvin wrote:
> >>On 02/28/2013 04:42 PM, Josh Boyer wrote:
> >>>On Fri, Mar 01, 2013 at 01:36:29AM +0100, Borislav Petkov wrote:
> >>>>On Thu, Feb 28, 2013 at 04:15:45PM -0800, H. Peter Anvin wrote:
> >>>>>>I'll try to get someone to test this tomorrow.
> >>>>Btw, you'd need to apply that other patch too
> >>>>
> >>>>http://marc.info/?l=xen-devel&m=136206183814547&w=2
> >>>>
> >>>>so that arch_flush_lazy_mmu_mode() has at least one caller on x86_64.
> >>>Yeah, we already have that applied. It stops crashes in xen
> >>>environments so we pulled it in as a bugfix. Thanks though!
> >>>
> >>Who are "we"?
> >Sorry, Fedora. That patch has a link to a bug in it. We applied the
> >patch for that bug. I'll apply Boris' patch on top and get the same
> >people to test it.
>
> Josh, have you had a chance to test this?

I've tested it on bare metal for a while now. No problems noticed at
all. I've not heard back from Krishna who was testing it in the Xen
environment. Krishna?

josh

2013-03-21 14:08:38

by Konrad Rzeszutek Wilk

[permalink] [raw]
Subject: Re: [PATCH] mm/x86: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

On Wed, Mar 13, 2013 at 09:44:43AM -0400, Josh Boyer wrote:
> On Wed, Mar 13, 2013 at 09:25:44AM -0400, Boris Ostrovsky wrote:
> > On 03/01/2013 07:14 AM, Josh Boyer wrote:
> > >On Thu, Feb 28, 2013 at 04:52:20PM -0800, H. Peter Anvin wrote:
> > >>On 02/28/2013 04:42 PM, Josh Boyer wrote:
> > >>>On Fri, Mar 01, 2013 at 01:36:29AM +0100, Borislav Petkov wrote:
> > >>>>On Thu, Feb 28, 2013 at 04:15:45PM -0800, H. Peter Anvin wrote:
> > >>>>>>I'll try to get someone to test this tomorrow.
> > >>>>Btw, you'd need to apply that other patch too
> > >>>>
> > >>>>http://marc.info/?l=xen-devel&m=136206183814547&w=2
> > >>>>
> > >>>>so that arch_flush_lazy_mmu_mode() has at least one caller on x86_64.
> > >>>Yeah, we already have that applied. It stops crashes in xen
> > >>>environments so we pulled it in as a bugfix. Thanks though!
> > >>>
> > >>Who are "we"?
> > >Sorry, Fedora. That patch has a link to a bug in it. We applied the
> > >patch for that bug. I'll apply Boris' patch on top and get the same
> > >people to test it.
> >
> > Josh, have you had a chance to test this?
>
> I've tested it on bare metal for a while now. No problems noticed at
> all. I've not heard back from Krishna who was testing it in the Xen
> environment. Krishna?

Roping in Stephan from Canonical as they are seeing it on a regular basis
and is affecting their distro.

Stephan - there are two patches for it - the paravirt of lazy_mmu mode
and then the other one.

This thread should provide the right URLs (I hope). Could you (if it is possible)
try them out and see if they fix the issue?

>
> josh