Re: [Xen-devel] [PATCH] x86/boot: re-arrange how/when we do disk I/O

[Julien Grall <julien.grall@xxxxxxx>]

Hi,

On 12/06/17 17:59, Julien Grall wrote:
> Hi Jan,
>
> On 12/06/17 16:27, Jan Beulich wrote:
> > > > > On 12.06.17 at 17:11, <JBeulich@xxxxxxxx> wrote:
> > > We place the trampoline no lower than at 256k, so we have ample space
> > > to read the MBRs of BIOS disks into an aligned buffer right below the
> > > trampoline (not doing so has been found to be a problem on a buggy BIOS
> > > coming with a Skull Canyon NUC). To facilitate that move MBR reading
> > > past EDD info retrieval.
> > >
> > > Also add a wrap check to the EDD info retrieval loop, to match that in
> > > the MBR reading one.
> > >
> > > Reported-by: Paul Durrant <Paul.Durrant@xxxxxxxxxx>
> > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> > > Tested-by: Paul Durrant <Paul.Durrant@xxxxxxxxxx>
> > As to 4.9 inclusion, I think I should have mentioned right away
> > that such a change of course isn't without risk: We're trying to
> > work around a BIOS bug by relying on other information
> > coming from the BIOS being correct / usable. Obviously there is
> > the risk that this regresses with some other BIOS having a bug
> > elsewhere.
> >
> > I'm therefore leaning towards suggesting to take this change
> > only for master right now, and consider pulling it into the 4.9
> > branch in a couple of weeks time, when the patch has seen at
> > least a little more testing on a wider set of systems.
> I agree on your conclusion. I would suggest to add a release note if it
> is not backported before the release.
>
> I will keep track of this.
I haven't seen any update on this. Can someone describe briefly the 
problem so we can add it in the section "known issues" of the release notes?
Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel