Re: [pve-devel] [PATCH v3 qemu-server] Prevent starting a 32-bit VM using a 64-bit OVMF BIOS

[Fiona Ebner <f.ebner@proxmox.com>]

Am 12.12.23 um 11:58 schrieb Filip Schauer:
> Instead of starting a VM with a 32-bit CPU type and a 64-bit OVMF image,
> throw an error before starting the VM telling the user that OVMF is not
> supported on 32-bit CPU types.
> 
> Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
> ---
> Changes since v2:
> * Simplify the check whether a 32-bit CPU type is used in combination
>   with OVMF
> 

Yes, it's much nicer than extending the EFI-related functions with new
parameters :)

>  PVE/QemuServer.pm | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index 2063e66..b25a3cd 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -3570,6 +3570,16 @@ my sub print_ovmf_drive_commandlines {
>      return ("if=pflash,unit=0,format=raw,readonly=on,file=$ovmf_code", $var_drive_str);
>  }
>  
> +my @cputypes_32bit = (
> +    '486',
> +    'pentium',
> +    'pentium2',
> +    'pentium3',
> +    'coreduo',
> +    'athlon',
> +    'kvm32',
> +    'qemu32',
> +);

I'd like to put this list in CPUConfig.pm and have a small helper
function there. The QemuServer.pm module already has way too many
functions and variables ;) And since it's only used for lookup, maybe
using a hash is better?

A short comment in the commit message about how you got the list would
be nice too (I just checked for absence of CPUID_EXT2_LM in
target/i386/cpu.c to verify your list).

>  sub config_to_command {
>      my ($storecfg, $vmid, $conf, $defaults, $forcemachine, $forcecpu,
>          $pbs_backing) = @_;
> @@ -3689,6 +3699,9 @@ sub config_to_command {
>      }
>  
>      if ($conf->{bios} && $conf->{bios} eq 'ovmf') {
> +	die "OVMF (UEFI) BIOS is not supported on 32-bit CPU types\n"
> +	    if ($conf->{cpu} && first {$_ eq $conf->{cpu}} @cputypes_32bit);

Style nit: usually we don't have parentheses for post-if