[ipxe-devel] [PATCH 2/2] [build] Disable TIVOLI_VMM_WORKAROUND in the qemu configuration

Ján ONDREJ (SAL) ondrejj at salstar.sk
Thu Oct 27 08:24:51 UTC 2016


On Thu, Oct 27, 2016 at 09:44:45AM +0200, Laszlo Ersek wrote:
> On 10/27/16 08:27, Ján ONDREJ (SAL) wrote:
> > Hello,
> > 
> >   I have troubles with this FXSAVE/FXRSTOR not only on qemu/kvm,
> > but with some older hardware too (HP server).
> > 
> >   Maybe this tivoli workaround should be disabled for all and enabled
> > only for tivoli.
> Hmmm. QEMU has a named configuration, and "bundling iPXE for QEMU" is a
> regular activity that the QEMU developer community does.

My site (boot.salstar.sk) is built for universal use, using it in qemu,
on real hardware, ...

Currently there is no run-time serial port configuration, so I need to build
at least 3 binaries of ipxe. I can't build more ipxe binaries for
each hardware, it's hard to use for users and hard to configure in dhcp.

> I don't think "iPXE for Tivoli" is a similarly well-defined environment
> or use case, so a build-time config for that seems unlikely.
> If the FXSAVE/FXRSTOR stuff breaks on real hardware as well, then I'm
> afraid the original analysis of FXSAVE/FXRSTOR availability, in commit
> 71560d185475, was inexact:

May be this is an problem of this vendor or this machine.

> If this assumption is unsafe after all, then I bet Michael will want to
> make FXSAVE/FXRSTOR dependent on dynamic feature detection (CPUID or
> similar -- maybe even detect the Tivoli VMM somehow, at runtime, like
> you said).

I already reported this to Michael on IRC long time ago,
also sent some emails to ipxe-devel, I think not replyed yet.


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