lxd/instance/drivers/driver_lxc: Configure LXC to use our custom CDI …

…hook if CDI devices have been configured

Signed-off-by: Gabriel Mougard <[email protected]>

lxd/instance/drivers/driver_lxc.go

@@ -41,6 +41,7 @@ import (
 	"github.com/canonical/lxd/lxd/db/cluster"
 	"github.com/canonical/lxd/lxd/db/operationtype"
 	"github.com/canonical/lxd/lxd/device"
+	"github.com/canonical/lxd/lxd/device/cdi"
 	deviceConfig "github.com/canonical/lxd/lxd/device/config"
 	"github.com/canonical/lxd/lxd/device/nictype"
 	"github.com/canonical/lxd/lxd/idmap"
@@ -2053,6 +2054,7 @@ func (d *lxc) startCommon() (string, []func() error, error) {
 	// Create the devices
 	nicID := -1
 	nvidiaDevices := []string{}
+	cdiHookFiles := []string{}
 
 	sortedDevices := d.expandedDevices.Sorted()
 	startDevices := make([]device.Device, 0, len(sortedDevices))
@@ -2223,6 +2225,10 @@ func (d *lxc) startCommon() (string, []func() error, error) {
 				if entry.Key == device.GPUNvidiaDeviceKey {
 					nvidiaDevices = append(nvidiaDevices, entry.Value)
 				}
+
+				if entry.Key == cdi.CDIHookFilepathKey {
+					cdiHookFiles = append(cdiHookFiles, entry.Value)
+				}
 			}
 		}
 	}
@@ -2235,6 +2241,24 @@ func (d *lxc) startCommon() (string, []func() error, error) {
 		}
 	}
 
+	if len(cdiHookFiles) > 0 {
+		err = lxcSetConfigItem(cc, "lxc.environment", fmt.Sprintf("CDI_HOOK_FILES=%s", strings.Join(cdiHookFiles, ",")))
+		if err != nil {
+			return "", nil, fmt.Errorf("Unable to set CDI_HOOK_FILES in LXC environment: %w", err)
+		}
+
+		lxdCDIHookPath := os.Getenv("LXD_CDI_HOOK")
+		if lxdCDIHookPath == "" {
+			return "", nil, fmt.Errorf("LXD_CDI_HOOK environment variable should be set to use custom CDI hooks")
+		}
+
+		// If CDI is used, we override the default `nvidia` LXC hook to use the CDI LXD hook.
+		err = lxcSetConfigItem(cc, "lxc.hook.mount", lxdCDIHookPath)
+		if err != nil {
+			return "", nil, fmt.Errorf("Unable to set CDI hook in LXC: %w", err)
+		}
+	}
+
 	// Load the LXC raw config.
 	err = d.loadRawLXCConfig(cc)
 	if err != nil {