Re: Is: 0xCF8 on extended config space instead of MCONF?

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Sep 09, 2014 at 04:00:51PM +0200, Trenta sis wrote:
> Hi,
> 
> We have tried with two differents servers but same type (HS20) and
> both with latest firmware, bios,...  and with same results, no
> working.
> as you decribed, if mmcfg is a new option added to xen >4.0 this could
> be the correct answer for this issue with this hardware. We were
> working with xen 3.2 and 4.0 with this hardware without any error or
> problem.
> Remember that HS20 are IBM blade server, I don't know if this could be
> a problem...
> 
> What do you think if we work enable mmcfg=0, this could be a correct
> solutions and we can work without any problems o incompatibilities?

Yes it should work - as you say - it is a blade hardware and it does
not have any SR-IOV functionality, so the MMCONF usage is not needed.

The SR-IOV functionality for blades came much much later.
> 
> Thanks
> 
> 
> 
> 2014-09-09 10:53 GMT+02:00 Ian Campbell <Ian.Campbell@citrix.com>:
> > On Tue, 2014-09-09 at 09:11 +0200, Trenta sis wrote:
> >> Hi,
> >>
> >> With xen 4.0 or citrix xenserver 5.6 works perfect, why you say that
> >> is a hardware issue if we don't use xen >4.0 works perfect?
> >
> > I'm afraid this doesn't rove anything, it could easily be that Xen <=
> > 4.0 simply doesn't tickle the bad hardware behaviour.
> >
> >>  Also I
> >> have tried with two differents server with same result,
> >
> > Two different servers or two of the same kind? It's not unexpected that
> > two of the same type of server would have the same firmware/hardware
> > issues.
> >
> > I think step one should be to make sure that you have the very latest
> > firmware (BIOS etc) for the hardware.
> >
> >>  I'm not sure
> >> that is a hardware issue after to do this test on both servers...
> >> Can you give me details about what is mmcfg, I have searched but I
> >> can't find any detailed information.
> >
> > AIUI it's an extended mechanism for accessing PCI configuration space.
> > Xen prior to 4.0 most likely didn't use this method which is why it
> > works ok.
> >
> > Ian.
> >>
> >>
> >> Thanks
> >>
> >>
> >>
> >> 2014-09-08 15:28 GMT+02:00 Jan Beulich <JBeulich@suse.com>:
> >> >>>> On 08.09.14 at 14:53, <trenta.sis@gmail.com> wrote:
> >> >> It seems that is not a hardware issue, it seems a problems with xen
> >> >> mmcfg with this hardware.
> >> >
> >> > I.e. it _is_ a hardware issue.
> >> >
> >> >> Will be solved?
> >> >
> >> > That's a question to the hardware vendor.
> >> >
> >> >> Can I use for a production
> >> >> environment this workaround?
> >> >
> >> > I guess so, if you're not requiring any of the functionality needed
> >> > extended config space access, like SR-IOV.
> >> >
> >> > Jan
> >> >
> >>
> >> _______________________________________________
> >> Xen-devel mailing list
> >> Xen-devel@lists.xen.org
> >> http://lists.xen.org/xen-devel
> >
> >
> 
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