[pve-devel] [PATCH common v3 3/3] HardwareMap: add support for multiple pci device paths per mapping

[Dominik Csapak <d.csapak@proxmox.com>]

With this, we can now tell qemu-server to choose the first avaiable
devices, which makes using vGPUs and SR-IOV capable devices much easier
to use, since the user does not have to hardcode the device, but can
give a list of identical ones, and qemu-server chooses dynamically.

note that we require the devices all to be the same vendor/device,
because we don't want to group unrelated devices, but we only check
the iommugroup for the first device, but there is a high chance
that this also changes when somethings off since e.g. SRIOV devices
are most often created at the same time, so when the any has a different
group, the first one will too

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/PVE/HardwareMap.pm | 71 ++++++++++++++++++++++++------------------
 1 file changed, 41 insertions(+), 30 deletions(-)

diff --git a/src/PVE/HardwareMap.pm b/src/PVE/HardwareMap.pm
index 31841b4..52c45e1 100644
--- a/src/PVE/HardwareMap.pm
+++ b/src/PVE/HardwareMap.pm
@@ -84,9 +84,11 @@ my $format = {
 	},
 	path => {
 	    description => "The path to the device. If the function is omitted, the whole device is"
-		." mapped. In that case use the attributes of the first device.",
+		." mapped. In that case use the attributes of the first device. You can give"
+		." multiple paths as a semicolon seperated list, the first available will then"
+		." be chosen on guest start.",
 	    type => 'string',
-	    pattern => "${PCI_RE}",
+	    pattern => "(?:${PCI_RE};)*${PCI_RE}",
 	},
 	mdev => {
 	    description => "The Device supports mediated devices.",
@@ -213,39 +215,48 @@ sub write_hardware_map {
 my $pci_valid = sub {
     my ($cfg) = @_;
 
-    my $multifunction = 0;
-    if ($path !~ m/\.[a-f0-9]/i) {
-	# whole device, add .0 (must exist)
-	$path = "$path.0";
-	$multifunction = 1;
-    }
+    my @paths = split(';', $cfg->{path} // '');
 
-    my $info = PVE::SysFSTools::pci_device_info($path, 1);
-    die "pci device '$path' not found\n" if !defined($info);
+    my $idx = 0;
+    for my $path (@paths) {
 
-    my $correct_props = {
-	vendor => $info->{vendor},
-	device => $info->{device},
-	'subsystem-vendor' => $info->{'subsystem_vendor'},
-	'subsystem-device' => $info->{'subsystem_device'},
-	mdev => $multifunction ? undef : $info->{mdev}, # don't allow mdev for multifunction
-	iommugroup => $info->{iommugroup},
-    };
+	my $multifunction = 0;
+	if ($path !~ m/\.[a-f0-9]/i) {
+	    # whole device, add .0 (must exist)
+	    $path = "$path.0";
+	    $multifunction = 1;
+	}
+
+	my $info = PVE::SysFSTools::pci_device_info($path, 1);
+	die "pci device '$path' not found\n" if !defined($info);
 
-    for my $prop (sort keys %$correct_props) {
-	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});
+	my $correct_props = {
+	    vendor => $info->{vendor},
+	    device => $info->{device},
+	    'subsystem-vendor' => $info->{'subsystem_vendor'},
+	    'subsystem-device' => $info->{'subsystem_device'},
+	    mdev => $multifunction ? undef : $info->{mdev}, # don't allow mdev for multifunction
+	    iommugroup => $info->{iommugroup},
+	};
+
+	for my $prop (sort keys %$correct_props) {
+	    next if $prop eq 'iommugroup' && $idx > 0; # check iommu only on the first device
 
-	my $correct_prop = $correct_props->{$prop};
-	$correct_prop =~ s/^0x//;
-	my $configured_prop = $cfg->{$prop};
-	$configured_prop =~ s/^0x//;
+	    next if !defined($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});
 
-	die "'$prop' does not match for '$cfg->{name}' ($correct_prop != $configured_prop)\n"
-	    if $correct_prop ne $configured_prop;
+	    my $correct_prop = $correct_props->{$prop};
+	    $correct_prop =~ s/^0x//;
+	    my $configured_prop = $cfg->{$prop};
+	    $configured_prop =~ s/^0x//;
+
+	    die "'$prop' does not match for '$cfg->{name}' ($correct_prop != $configured_prop)\n"
+		if $correct_prop ne $configured_prop;
+	}
+	$idx++;
     }
 
     return 1;
-- 
2.30.2