Re: [Qemu-devel] [PATCH 1/3] pc: Set hw_version on all machine classes

[Eduardo Habkost]

On Tue, Sep 22, 2015 at 10:26:14PM +0200, Laszlo Ersek wrote:
> On 09/22/15 22:16, Eduardo Habkost wrote:
> > In 2012, QEMU had a bug where it exposed QEMU version information to the
> > guest, meaning a QEMU upgrade would expose different hardware to the
> > guest OS even if the same machine-type is being used.
> > 
> > The bug was fixed by commit 93bfef4c6e4b23caea9d51e1099d06433d8835a4, on
> > all machines up to pc-1.0. But we kept introducing the same bug on all
> > newer machines since then. That means we are breaking guest ABI every
> > time QEMU was upgraded.
> > 
> > Fix this by setting the hw_version on all PC machines, making sure the
> > hardware won't change when upgrading QEMU.
> > 
> > Note that QEMU_VERSION was "1.0" in QEMU 1.0, but starting on QEMU
> > 1.1.0, it started following the "x.y.0" pattern. We have to follow it,
> > to make sure we use the right QEMU_VERSION string from each QEMU
> > release.
> > 
> > The 2.5 machine classes could have hw_version unset, because the default
> > value for qemu_get_version() is QEMU_VERSION. But I decided to set it
> > explicitly to QEMU_VERSION so we don't forget to update it to "2.5.0"
> > after we release 2.5.0 and create a 2.6 machine class.
> > 
> > Signed-off-by: Eduardo Habkost <address@hidden>
> > ---
[...]
> 
> Can you please add:
> 
> Reported-by: Laszlo Ersek <address@hidden>
> 
> to this patch? (If you agree, that is.)

Of course! :)

(Sorry, while trying to finish and submit the series before the end of
the day, I forgot to give you credit for finding this 3-year-old bug)

> 
> Other than that, while I'm sure you'll need (and get) other reviews too:
> 
> Reviewed-by: Laszlo Ersek <address@hidden>

Thanks!

-- 
Eduardo