Re: [PULL 31/53] hw/i386/pc: Default to use SMBIOS 3.0 for newer machine models

[Fiona Ebner]

Am 26.06.23 um 14:29 schrieb Michael S. Tsirkin:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> 
> Currently, pc-q35 and pc-i44fx machine models are default to use SMBIOS 2.8
> (32-bit entry point). Since SMBIOS 3.0 (64-bit entry point) is now fully
> supported since QEMU 7.0, default to use SMBIOS 3.0 for newer machine
> models. This is necessary to avoid the following message when launching
> a VM with large number of vcpus.
> 
>    "SMBIOS 2.1 table length 66822 exceeds 65535"
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> Message-Id: <20230607205717.737749-2-suravee.suthikulpanit@amd.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Hi,

we received some reports about the new default causing issues for
certain guest OSes [0][1]. Namely, for Juniper vSRX, where boot fails
and Microsoft Windows, where querying an UUID set via QEMU cmdline
-smbios 'type=1,uuid=a4656bd0-a07d-48e0-9dfd-bdc84667a8d0'
in Powershell with
get-wmiobject win32_computersystemproduct | Select-Object
-expandProperty UUID
doesn't return any value anymore and can trip up some guest
applications. The original report is about Windows 10 and I reproduced
this with Windows Server 2019 and the German (but I hope it doesn't
matter this time) version of Windows Server 2022.

Using machine type 8.0 or the machine option smbios-entry-point-type=32
are workarounds.

Since Windows is widely used, that seems a bit unfortunate. Just wanted
to ask if you are aware of the issue and if there is something else that
can be done other than specifying the more specific machine commandline
for those OSes?

Best Regards,
Fiona

[0]: https://forum.proxmox.com/threads/136942/
[1]: https://forum.proxmox.com/threads/136227/post-610277