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Date: Wed, 11 Jul 2018 12:32:54 -0300
From: Eduardo Habkost <ehabkost@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH for-3.0] pc: Use "3.0+" constant as default
 SMBIOS version
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To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= <berrange@redhat.com>
Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>, Wei Huang <wei@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Andrew Jones <drjones@redhat.com>, Igor Mammedov <imammedo@redhat.com>

On Tue, Jul 10, 2018 at 10:07:31AM +0100, Daniel P. Berrang=E9 wrote:
> On Mon, Jul 09, 2018 at 05:37:31PM -0300, Eduardo Habkost wrote:
> > Every time we create new PC machine-types in QEMU, the defaults
> > for SMBIOS fields change unnecessarily because the version field
> > defaults to MachineClass::name.
> >=20
> > This can cause unexpected side-effects, like triggering license
> > reactivation on guest software, or changing the VM memory layout
> > because of BIOS table size changes.
>=20
> Does that really matter though ? By its very nature the 'Version'
> field in SMBIOS is expected to change if you alter something about
> the hardware. If guests OS don't want to be exposed to changes in
> SMBIOS they would be using a fixed machine type, not the variable
> "pc" type that continually changes.
>=20
> We could put padding in the string if we want to avoid BIOS table
> layout changes.
>=20
> Having version change though feels like it is working as intended
> for the semantics of these Version: fields in BIOS.

Michael, do you have additional info on the original motivation
for suggesting this change and why do you consider it a bug?
(I don't have any concrete examples to justify the change)

--=20
Eduardo