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From: Michael Ellerman <mpe@ellerman.id.au>
To: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Cc: paulus@samba.org, Laurent Dufour <ldufour@linux.vnet.ibm.com>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pseries/le: Fix another endiannes issue in RTAS call from xmon
Date: Fri, 16 Jan 2015 14:02:41 +1100	[thread overview]
Message-ID: <1421377361.18166.2.camel@ellerman.id.au> (raw)
In-Reply-To: <54B85016.4080906@linux.vnet.ibm.com>

On Thu, 2015-01-15 at 15:41 -0800, Tyrel Datwyler wrote:
> On 01/15/2015 02:19 PM, Michael Ellerman wrote:
> > On Thu, 2015-01-15 at 11:44 -0800, Tyrel Datwyler wrote:
> >> On 01/15/2015 09:23 AM, Laurent Dufour wrote:
> >>> The commit 3b8a3c010969 ("powerpc/pseries: Fix endiannes issue in RTAS
> >>> call from xmon") was fixing an endianness issue in the call made from
> >>> xmon to RTAS.
> >>>
> >>> However, as Michael Ellerman noticed, this fix was not complete, the
> >>> token value was not byte swapped. This lead to call an unexpected and
> >>> most of the time unexisting RTAS function, which is silently ignored
> >>> by RTAS.
> >>
> >> Nit. Not so much that is silently ignored by RTAS as much as
> >> disable_surveillance silently doesn't check the return status of the
> >> RTAS call. Maybe a check is warranted and reporting of non-success.
> > 
> > Yeah you're right, I added a printf of the result and got -3, which is also
> > wrong as far as I can tell, but I didn't have the energy to chase it any
> > further.
> 
> If this was on a powerkvm guest set-indicator should be present for
> hotplug (DLPAR) support. However, the surveillance indicator would not
> be implemented. I know sometimes I forget if I'm on a powervm or
> powerkvm guest. Just a thought.

Right that does explain it. I went looking for the KVM kernel/qemu code that
implements set-indicator but couldn't find it. Presumably it's in some branch
other than the one I was looking at, or I was grepping for the wrong thing.

So I guess a printf there is probably not helpful, because it will fire always
on PowerKVM (at least at the moment).

cheers

WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe@ellerman.id.au>
To: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org,
	Laurent Dufour <ldufour@linux.vnet.ibm.com>,
	paulus@samba.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pseries/le: Fix another endiannes issue in RTAS call from xmon
Date: Fri, 16 Jan 2015 14:02:41 +1100	[thread overview]
Message-ID: <1421377361.18166.2.camel@ellerman.id.au> (raw)
In-Reply-To: <54B85016.4080906@linux.vnet.ibm.com>

On Thu, 2015-01-15 at 15:41 -0800, Tyrel Datwyler wrote:
> On 01/15/2015 02:19 PM, Michael Ellerman wrote:
> > On Thu, 2015-01-15 at 11:44 -0800, Tyrel Datwyler wrote:
> >> On 01/15/2015 09:23 AM, Laurent Dufour wrote:
> >>> The commit 3b8a3c010969 ("powerpc/pseries: Fix endiannes issue in RTAS
> >>> call from xmon") was fixing an endianness issue in the call made from
> >>> xmon to RTAS.
> >>>
> >>> However, as Michael Ellerman noticed, this fix was not complete, the
> >>> token value was not byte swapped. This lead to call an unexpected and
> >>> most of the time unexisting RTAS function, which is silently ignored
> >>> by RTAS.
> >>
> >> Nit. Not so much that is silently ignored by RTAS as much as
> >> disable_surveillance silently doesn't check the return status of the
> >> RTAS call. Maybe a check is warranted and reporting of non-success.
> > 
> > Yeah you're right, I added a printf of the result and got -3, which is also
> > wrong as far as I can tell, but I didn't have the energy to chase it any
> > further.
> 
> If this was on a powerkvm guest set-indicator should be present for
> hotplug (DLPAR) support. However, the surveillance indicator would not
> be implemented. I know sometimes I forget if I'm on a powervm or
> powerkvm guest. Just a thought.

Right that does explain it. I went looking for the KVM kernel/qemu code that
implements set-indicator but couldn't find it. Presumably it's in some branch
other than the one I was looking at, or I was grepping for the wrong thing.

So I guess a printf there is probably not helpful, because it will fire always
on PowerKVM (at least at the moment).

cheers



  reply	other threads:[~2015-01-16  3:02 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-24 14:07 [PATCH] pseries/le: Fix endiannes issue in RTAS call from xmon Laurent Dufour
2014-11-24 14:07 ` Laurent Dufour
2014-11-26  3:31 ` Michael Ellerman
2014-11-26  8:19   ` Laurent Dufour
2015-01-15  4:25 ` [PATCH] " Michael Ellerman
2015-01-15  4:25   ` Michael Ellerman
2015-01-15 14:17   ` Laurent Dufour
2015-01-15 14:17     ` Laurent Dufour
2015-01-15 17:23   ` [PATCH] pseries/le: Fix another " Laurent Dufour
2015-01-15 17:23     ` Laurent Dufour
2015-01-15 19:44     ` Tyrel Datwyler
2015-01-15 19:44       ` Tyrel Datwyler
2015-01-15 22:19       ` Michael Ellerman
2015-01-15 22:19         ` Michael Ellerman
2015-01-15 23:41         ` Tyrel Datwyler
2015-01-15 23:41           ` Tyrel Datwyler
2015-01-16  3:02           ` Michael Ellerman [this message]
2015-01-16  3:02             ` Michael Ellerman
2015-01-16 10:19             ` Laurent Dufour
2015-01-16 10:19               ` Laurent Dufour

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