[no-relnote] Add MIG discoverer to dgpu package

Signed-off-by: Evan Lezar <elezar@nvidia.com>

internal/platform-support/dgpu/dgpu.go

@@ -24,7 +24,6 @@ import (
 )
 
 // NewForDevice creates a discoverer for the specified Device.
-// nvsandboxutils is used for discovery if specified, otherwise NVML is used.
 func NewForDevice(d device.Device, opts ...Option) (discover.Discover, error) {
 	o := &options{}
 	for _, opt := range opts {
@@ -37,3 +36,22 @@ func NewForDevice(d device.Device, opts ...Option) (discover.Discover, error) {
 
 	return o.newNvmlDGPUDiscoverer(&toRequiredInfo{d})
 }
+
+// NewForDevice creates a discoverer for the specified device and its associated MIG device.
+func NewForMigDevice(d device.Device, mig device.MigDevice, opts ...Option) (discover.Discover, error) {
+	o := &options{}
+	for _, opt := range opts {
+		opt(o)
+	}
+
+	if o.logger == nil {
+		o.logger = logger.New()
+	}
+
+	return o.newNvmlMigDiscoverer(
+		&toRequiredMigInfo{
+			MigDevice: mig,
+			parent:    &toRequiredInfo{d},
+		},
+	)
+}

internal/platform-support/dgpu/nvml.go

@@ -24,19 +24,20 @@ import (
 
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/discover"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/info/drm"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/nvcaps"
 )
 
 type requiredInfo interface {
 	GetMinorNumber() (int, error)
 	GetPCIBusID() (string, error)
+	getDevNodePath() (string, error)
 }
 
 func (o *options) newNvmlDGPUDiscoverer(d requiredInfo) (discover.Discover, error) {
-	minor, err := d.GetMinorNumber()
+	path, err := d.getDevNodePath()
 	if err != nil {
-		return nil, fmt.Errorf("error getting GPU device minor number: %w", err)
+		return nil, fmt.Errorf("error getting device node path: %w", err)
 	}
-	path := fmt.Sprintf("/dev/nvidia%d", minor)
 
 	pciBusID, err := d.GetPCIBusID()
 	if err != nil {
@@ -71,6 +72,52 @@ func (o *options) newNvmlDGPUDiscoverer(d requiredInfo) (discover.Discover, erro
 	return dd, nil
 }
 
+type requiredMigInfo interface {
+	getPlacementInfo() (int, int, int, error)
+	getDevNodePath() (string, error)
+}
+
+func (o *options) newNvmlMigDiscoverer(d requiredMigInfo) (discover.Discover, error) {
+	gpu, gi, ci, err := d.getPlacementInfo()
+	if err != nil {
+		return nil, fmt.Errorf("error getting placement info: %w", err)
+	}
+
+	migCaps, err := nvcaps.NewMigCaps()
+	if err != nil {
+		return nil, fmt.Errorf("error getting MIG capability device paths: %v", err)
+	}
+
+	giCap := nvcaps.NewGPUInstanceCap(gpu, gi)
+	giCapDevicePath, err := migCaps.GetCapDevicePath(giCap)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get GI cap device path: %v", err)
+	}
+
+	ciCap := nvcaps.NewComputeInstanceCap(gpu, gi, ci)
+	ciCapDevicePath, err := migCaps.GetCapDevicePath(ciCap)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get CI cap device path: %v", err)
+	}
+
+	parentPath, err := d.getDevNodePath()
+	if err != nil {
+		return nil, err
+	}
+
+	deviceNodes := discover.NewCharDeviceDiscoverer(
+		o.logger,
+		o.devRoot,
+		[]string{
+			parentPath,
+			giCapDevicePath,
+			ciCapDevicePath,
+		},
+	)
+
+	return deviceNodes, nil
+}
+
 type toRequiredInfo struct {
 	device.Device
 }
@@ -82,3 +129,40 @@ func (d *toRequiredInfo) GetMinorNumber() (int, error) {
 	}
 	return minor, nil
 }
+
+func (d *toRequiredInfo) getDevNodePath() (string, error) {
+	minor, err := d.GetMinorNumber()
+	if err != nil {
+		return "", fmt.Errorf("error getting GPU device minor number: %w", err)
+	}
+	path := fmt.Sprintf("/dev/nvidia%d", minor)
+	return path, nil
+}
+
+type toRequiredMigInfo struct {
+	device.MigDevice
+	parent requiredInfo
+}
+
+func (d *toRequiredMigInfo) getPlacementInfo() (int, int, int, error) {
+	gpu, ret := d.parent.GetMinorNumber()
+	if ret != nvml.SUCCESS {
+		return 0, 0, 0, fmt.Errorf("error getting GPU minor: %v", ret)
+	}
+
+	gi, ret := d.GetGpuInstanceId()
+	if ret != nvml.SUCCESS {
+		return 0, 0, 0, fmt.Errorf("error getting GPU Instance ID: %v", ret)
+	}
+
+	ci, ret := d.GetComputeInstanceId()
+	if ret != nvml.SUCCESS {
+		return 0, 0, 0, fmt.Errorf("error getting Compute Instance ID: %v", ret)
+	}
+
+	return gpu, gi, ci, nil
+}
+
+func (d *toRequiredMigInfo) getDevNodePath() (string, error) {
+	return d.parent.getDevNodePath()
+}