[pve-devel] [PATCH qemu-server] Simplify QEMU version check and require 3.0+

[Thomas Lamprecht]

On 2/10/20 11:31 AM, Stefan Reiter wrote:
> Some of the recent QMP changes require at least 2.12.0, but since the
> oldest version we officially package for 6.x is 4.0.0 anyway, checking
> for at least 3.0 should not break anyone's setup.
> 
> Note that this does not affect machine version checks, only the
> installed QEMU binary version.
> 
> Signed-off-by: Stefan Reiter <s.reiter at proxmox.com>
> ---
> 
> Previous minimum was 0.15, but I have a feeling that even if you managed to
> install QEMU 0.15 somehow, it wouldn't have worked anyway.
> 
> 3.0 is a reasonable requirement IMO, although technically 2.12 would probably
> work too, if there's a use-case for using such an outdated QEMU.
> 
>  PVE/QemuServer.pm | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index 318ee54..de09d90 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -3405,7 +3405,6 @@ sub config_to_command {
>      my $devices = [];
>      my $pciaddr = '';
>      my $bridges = {};
> -    my $vernum = 0; # unknown
>      my $ostype = $conf->{ostype};
>      my $winversion = windows_version($ostype);
>      my $kvm = $conf->{kvm};
> @@ -3415,6 +3414,11 @@ sub config_to_command {
>      my $kvm_binary = get_command_for_arch($arch);
>      my $kvmver = kvm_user_version($kvm_binary);
>  
> +    $kvmver =~ m/^(\d+)\.(\d+)/;
> +    if ($1 < 3) {
> +	die "Detected old QEMU binary ('$kvmver', at least 3.0 is required)\n";
> +    }

this is a slight change in behavior though, previously we died if the regex did not
match, as $vernum defaulted to zero and thus was < 15000. Now we do not anymore,
(kvm_user_version does not die on failed detection)

Maybe:

my (undef, $vmajor, $vminor) = $kvmver =~ m/^(\d+)\.(\d+)/;
if (!$vmajor || $vmajor < 3) {
    die ...


> +
>      my $add_pve_version = min_version($kvmver, 4, 1);
>  
>      my $machine_type = get_vm_machine($conf, $forcemachine, $arch, $add_pve_version);
> @@ -3430,14 +3434,6 @@ sub config_to_command {
>  	    if !defined kvm_version();
>      }
>  
> -    if ($kvmver =~ m/^(\d+)\.(\d+)$/) {
> -	$vernum = $1*1000000+$2*1000;
> -    } elsif ($kvmver =~ m/^(\d+)\.(\d+)\.(\d+)$/) {
> -	$vernum = $1*1000000+$2*1000+$3;
> -    }
> -
> -    die "detected old qemu-kvm binary ($kvmver)\n" if $vernum < 15000;
> -
>      my $q35 = PVE::QemuServer::Machine::machine_type_is_q35($conf);
>      my $hotplug_features = parse_hotplug_features(defined($conf->{hotplug}) ? $conf->{hotplug} : '1');
>      my $use_old_bios_files = undef;
>