[pve-devel] [PATCH qemu-server v2 2/2] pci: call hookscript for each prepared pci device

[Dominik Csapak]

There are situations where a user might want to do extra things
for a passed through PCI device after it has been prepared/created (e.g.
in case of vGPU/mdev) but before the actual QEMU process is started.

Two examples are (both are used with NVIDIA vGPUs):
* setting 'vgpu_params' such as removing the frame-rate-limiter
* setting the gpu_instance_id for MIG devices

So instead of creating (nvidia-specific) interfaces for these, give a
user the ability to do it themselves via the hookscript as a first step.

Call it for each prepared device, so that we can give the hookscript the
'hostpciX' id, and the used uuid (in case of mdevs) or the pci id (in
case of regular or modern vGPU passthrough).

Include the generated mdev uuid in the return value of
`prepare_pci_device`, to avoid having to generate that multiple times.
With that we can get rid of one extra generation here too.

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
changes from v1:
* adapt to new location and uuid code from previous patch
* use a hash for the parameters now, and always give the pciid, even
  if we have a uuid

 src/PVE/QemuServer/PCI.pm | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/PVE/QemuServer/PCI.pm b/src/PVE/QemuServer/PCI.pm
index f778c60f..5d9c7ab2 100644
--- a/src/PVE/QemuServer/PCI.pm
+++ b/src/PVE/QemuServer/PCI.pm
@@ -761,9 +761,28 @@ sub prepare_pci_devices {
             if ($d->{mdev} || $d->{nvidia}) {
                 warn $@ if $@;
                 $chosen_mdev = $info;
-                last if $chosen_mdev; # if successful, we're done
+                if (defined($chosen_mdev)) {
+                    my $params = { id => $id, pciid => $chosen_mdev->{name} };
+                    $params->{mdev_uuid} = $chosen_mdev->{uuid};
+                    PVE::GuestHelpers::exec_hookscript(
+                        $conf, $vmid, 'post-pci-prepare', 1, $params,
+                    );
+                    last;
+                }
             } else {
                 die $@ if $@;
+                if (defined($info)) {
+                    PVE::GuestHelpers::exec_hookscript(
+                        $conf,
+                        $vmid,
+                        'post-pci-prepare',
+                        1,
+                        {
+                            id => $id,
+                            pciid => $info->{name},
+                        },
+                    );
+                }
             }
         }
 
@@ -774,7 +793,7 @@ sub prepare_pci_devices {
         # that here, so returnt any mdev uuid to signal we want one and as a fallback,
         # in case there is not smbios uuid
         if (!defined($uuid) && $chosen_mdev->{vendor} =~ m/^(0x)?10de$/) {
-            $uuid = generate_mdev_uuid($vmid, $index) if !defined($uuid);
+            $uuid = $chosen_mdev->{uuid} if !defined($uuid);
         }
     }
 
@@ -795,6 +814,7 @@ sub prepare_pci_device {
     } elsif (my $mdev = $device->{mdev}) {
         my $uuid = generate_mdev_uuid($vmid, $index);
         PVE::SysFSTools::pci_create_mdev_device($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