Re: [pve-devel] [PATCH guest-common v2 2/5] mapping: pci: rework properties check

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

On 10/04/2024 13:03, Dominik Csapak wrote:
> refactors the actual checking out to its own sub, so we can reuse it
> later
> 
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
>  src/PVE/Mapping/PCI.pm | 43 +++++++++++++++++++++++++-----------------
>  1 file changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/src/PVE/Mapping/PCI.pm b/src/PVE/Mapping/PCI.pm
> index 725e106..fcf07c0 100644
> --- a/src/PVE/Mapping/PCI.pm
> +++ b/src/PVE/Mapping/PCI.pm
> @@ -129,6 +129,26 @@ sub options {
>      };
>  }
>  
> +my sub check_properties {

s/check/assert/ and ideally some words that better describe what is
actually asserted here.

> +    my ($correct, $configured, $path, $name) = @_;

maybe s/correct/expected/ would be slightly better in conveying that the
passed $configured one do not only need to be all in the first hash, but
that all keys of the first hash

> +    for my $prop (sort keys %$correct) {
> +	next if !defined($correct->{$prop}) && !defined($configured->{$prop});
> +
> +	die "no '$prop' for device '$path'\n"

pre-existing, but maybe this would be slightly better worded like:

"missing expected property '$prop' for device '$path'\n" 

(no hard feelings though)

> +	    if defined($correct->{$prop}) && !defined($configured->{$prop});
> +	die "'$prop' configured but should not be\n"

also pre-existing, but I would adapt the error message to something like:

"unknown property '$prop' configured for device '$path'\n"

(slightly hard feelings here ;-))

(btw. would it make sense to also add $name?)


> +	    if !defined($correct->{$prop}) && defined($configured->{$prop});

can above check even trigger if we just go through the expected ($correct)
set of properties? Or are existing, but undef, entries in $correct the
forbidden ones, and other extra properties in $configured do not matter?

(I dind't check the full picture, so excuse me if this would be obvious,
but them IMO some comments would be warranted)

> +
> +	my $correct_prop = $correct->{$prop};
> +	$correct_prop =~ s/0x//g;
> +	my $configured_prop = $configured->{$prop};
> +	$configured_prop =~ s/0x//g;
> +
> +	die "'$prop' does not match for '$name' ($correct_prop != $configured_prop)\n"
> +	    if $correct_prop ne $configured_prop;
> +    }
> +}
> +
>  # checks if the given config is valid for the current node
>  sub assert_valid {
>      my ($name, $cfg) = @_;
> @@ -150,30 +170,19 @@ sub assert_valid {
>  
>  	my $correct_props = {
>  	    id => "$info->{vendor}:$info->{device}",
> -	    iommugroup => $info->{iommugroup},
>  	};
>  
> +	# check iommu only on the first device
> +	if ($idx == 0) {
> +	    $correct_props->{iommugroup} = $info->{iommugroup};
> +	}

is this really the same than what got removed in the loop?

As if the next ID 

> +
>  	if (defined($info->{'subsystem_vendor'}) && defined($info->{'subsystem_device'})) {
>  	    $correct_props->{'subsystem-id'} = "$info->{'subsystem_vendor'}:$info->{'subsystem_device'}";
>  	}
>  
> -	for my $prop (sort keys %$correct_props) {
> -	    next if $prop eq 'iommugroup' && $idx > 0; # check iommu only on the first device
> -
> -	    next if !defined($correct_props->{$prop}) && !defined($cfg->{$prop});
> -	    die "no '$prop' for device '$path'\n"
> -		if defined($correct_props->{$prop}) && !defined($cfg->{$prop});
> -	    die "'$prop' configured but should not be\n"
> -		if !defined($correct_props->{$prop}) && defined($cfg->{$prop});
> +	check_properties($correct_props, $cfg, $path, $name);
>  
> -	    my $correct_prop = $correct_props->{$prop};
> -	    $correct_prop =~ s/0x//g;
> -	    my $configured_prop = $cfg->{$prop};
> -	    $configured_prop =~ s/0x//g;
> -
> -	    die "'$prop' does not match for '$name' ($correct_prop != $configured_prop)\n"
> -		if $correct_prop ne $configured_prop;
> -	}
>  	$idx++;
>      }
>