[PATCH qemu-server v4 5/7] pci: preparation: mdev: only generate uuid once

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

In `prepare_pci_device` we already generate a uuid for the mdev. Later,
for NVIDIA vGPU, we need the uuid again to add it to the qemu cmdline.
Instead of generating it twice, return it from `prepare_pci_device` and
reuse that if we can.

If the device uses the modern nvidia vgpu stack, we don't need to create
a mdev, so generate the fallback uuid in `prepare_pci_devices`.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/PVE/QemuServer/PCI.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/PVE/QemuServer/PCI.pm b/src/PVE/QemuServer/PCI.pm
index f7167dcc..5d2fdabb 100644
--- a/src/PVE/QemuServer/PCI.pm
+++ b/src/PVE/QemuServer/PCI.pm
@@ -739,7 +739,8 @@ sub prepare_pci_devices {
 
         # nvidia vgpu needs a uuid as qemu parameter
         if (!defined($uuid) && $chosen_mdev->{vendor} =~ m/^(0x)?10de$/) {
-            $uuid = PVE::QemuServer::PCI::Mdev::generate_mdev_uuid($vmid, $index);
+            $uuid = $chosen_mdev->{uuid}
+                // PVE::QemuServer::PCI::Mdev::generate_mdev_uuid($vmid, $index);
         }
     }
 
@@ -760,6 +761,7 @@ sub prepare_pci_device {
     } elsif (my $mdev = $device->{mdev}) {
         my $uuid = PVE::QemuServer::PCI::Mdev::generate_mdev_uuid($vmid, $index);
         PVE::QemuServer::PCI::Mdev::pci_create_mdev_device($pciid, $uuid, $mdev);
+        $info->{uuid} = $uuid;
     } else {
         die "can't unbind/bind PCI group to VFIO '$pciid'\n"
             if !PVE::SysFSTools::pci_dev_group_bind_to_vfio($pciid);
-- 
2.47.3