[pve-devel] [PATCH qemu-server v2 1/2] automatically add 'uuid' parameter when passing through NVIDIA vGPU

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

When passing through an NVIDIA vGPU via mediated devices, their
software needs the qemu process to have the 'uuid' parameter set to the
one of the vGPU. Since it's currently not possible to pass through multiple
vGPUs to one VM (seems to be an NVIDIA driver limitation at the moment),
we don't have to take care about that.

Sadly, the place we do this, it does not show up in 'qm showcmd' as we
don't (want to) query the pci devices in that case, and then we don't
have a way of knowing if it's an NVIDIA card or not. But since this
is informational with QEMU anyway, i'd say we can ignore that.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 PVE/QemuServer.pm     | 9 ++++++++-
 PVE/QemuServer/PCI.pm | 4 +++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 7d9cf22..c706653 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -5594,12 +5594,19 @@ sub vm_start_nolock {
     PVE::QemuServer::PCI::reserve_pci_usage($pci_id_list, $vmid, $start_timeout);
 
     eval {
+	my $uuid;
 	for my $id (sort keys %$pci_devices) {
 	    my $d = $pci_devices->{$id};
 	    for my $dev ($d->{pciid}->@*) {
-		PVE::QemuServer::PCI::prepare_pci_device($vmid, $dev->{id}, $id, $d->{mdev});
+		my $info = PVE::QemuServer::PCI::prepare_pci_device($vmid, $dev->{id}, $id, $d->{mdev});
+
+		# nvidia grid needs the uuid of the mdev as qemu parameter
+		if ($d->{mdev} && !defined($uuid) && $info->{vendor} eq '10de') {
+		    $uuid = PVE::QemuServer::PCI::generate_mdev_uuid($vmid, $id);
+		}
 	    }
 	}
+	push @$cmd, '-uuid', $uuid if defined($uuid);
     };
     if (my $err = $@) {
 	eval { PVE::QemuServer::PCI::remove_pci_reservation($pci_id_list) };
diff --git a/PVE/QemuServer/PCI.pm b/PVE/QemuServer/PCI.pm
index 23fe508..3d0e70e 100644
--- a/PVE/QemuServer/PCI.pm
+++ b/PVE/QemuServer/PCI.pm
@@ -253,7 +253,7 @@ sub get_pci_addr_map {
     return $pci_addr_map;
 }
 
-my sub generate_mdev_uuid {
+sub generate_mdev_uuid {
     my ($vmid, $index) = @_;
     return sprintf("%08d-0000-0000-0000-%012d", $index, $vmid);
 }
@@ -514,6 +514,8 @@ sub prepare_pci_device {
 	die "can't reset PCI device '$pciid'\n"
 	    if $info->{has_fl_reset} && !PVE::SysFSTools::pci_dev_reset($info);
     }
+
+    return $info;
 }
 
 my $RUNDIR = '/run/qemu-server';
-- 
2.30.2