Add custom filters for processing accelerators

Author: mlorenzofr

README.md

@@ -966,6 +966,16 @@ Each `ghw.AcceleratorDevice` struct contains the following fields:
   describing the processing accelerator card. This may be `nil` if no PCI device
   information could be determined for the card.
 
+#### filters
+The `ghw.Accelerator()` function accepts a slice of filters, of type string, as parameter
+in format `[<vendor>]:[<device>][:<class>]`, (same is the _lspci_ command).
+
+Some filter examples:
+* `::0302`. Select 3D controller cards.
+* `10de::0302`. Select Nvidia (`10de`) 3D controller cards (`0302`).
+* `1da3:1060:1200`. Select Habana Labs (`1da3`) Gaudi3 (`1060`) processing accelerator cards (`1200`).
+* `1002::`. Select AMD ATI hardware.
+
 ```go
 package main
 
@@ -976,7 +986,11 @@ import (
 )
 
 func main() {
-	accel, err := ghw.Accelerator()
+	filter := make([]string, 0)
+	// example of a filter to detect 3D controllers
+	// filter = append(filter, "::0302")
+
+	accel, err := ghw.Accelerator(filter)
 	if err != nil {
 		fmt.Printf("Error getting processing accelerator info: %v", err)
 	}

cmd/ghwc/commands/accelerator.go

@@ -23,7 +23,9 @@ var acceleratorCmd = &cobra.Command{
 
 // showAccelerator show processing accelerators information for the host system.
 func showAccelerator(cmd *cobra.Command, args []string) error {
-	accel, err := ghw.Accelerator()
+	filter := make([]string, 0)
+
+	accel, err := ghw.Accelerator(filter)
 	if err != nil {
 		return errors.Wrap(err, "error getting Accelerator info")
 	}

host.go

@@ -73,7 +73,7 @@ func Host(opts ...*WithOption) (*HostInfo, error) {
 	if err != nil {
 		return nil, err
 	}
-	acceleratorInfo, err := accelerator.New(opts...)
+	acceleratorInfo, err := accelerator.New([]string{}, opts...)
 	if err != nil {
 		return nil, err
 	}

pkg/accelerator/accelerator.go

@@ -37,15 +37,19 @@ func (dev *AcceleratorDevice) String() string {
 }
 
 type Info struct {
-	ctx     *context.Context
-	Devices []*AcceleratorDevice `json:"devices"`
+	ctx              *context.Context
+	Devices          []*AcceleratorDevice `json:"devices"`
+	DiscoveryFilters []string
 }
 
 // New returns a pointer to an Info struct that contains information about the
 // accelerator devices on the host system
-func New(opts ...*option.Option) (*Info, error) {
+func New(filter []string, opts ...*option.Option) (*Info, error) {
 	ctx := context.New(opts...)
-	info := &Info{ctx: ctx}
+	info := &Info{
+		ctx:              ctx,
+		DiscoveryFilters: filter,
+	}
 
 	if err := ctx.Do(info.load); err != nil {
 		return nil, err

pkg/accelerator/accelerator_linux.go

@@ -6,10 +6,12 @@
 package accelerator
 
 import (
-	"github.com/samber/lo"
+	"fmt"
+	"strings"
 
 	"github.com/jaypipes/ghw/pkg/context"
 	"github.com/jaypipes/ghw/pkg/pci"
+	"github.com/samber/lo"
 )
 
 // PCI IDs list available at https://admin.pci-ids.ucw.cz/read/PD
@@ -60,13 +62,61 @@ func (i *Info) load() error {
 		if !isAccelerator(device) {
 			continue
 		}
-		accelDev := &AcceleratorDevice{
-			Address:   device.Address,
-			PCIDevice: device,
+		for _, filter := range i.DiscoveryFilters {
+			if validate(filter, device) {
+				accelDev := &AcceleratorDevice{
+					Address:   device.Address,
+					PCIDevice: device,
+				}
+				accelDevices = append(accelDevices, accelDev)
+				break
+			}
 		}
-		accelDevices = append(accelDevices, accelDev)
 	}
 
 	i.Devices = accelDevices
 	return nil
 }
+
+// validate checks if a given PCI device matches the provided filter string.
+//
+// The filter string is expected to be in the format "VendorID:ProductID:Class+Subclass".
+// Each part of the filter (VendorID, ProductID, Class+Subclass) is optional and can be
+// left empty, in which case the corresponding attribute is ignored during validation.
+//
+// Parameters:
+//   - filter: A string in the form "VendorID:ProductID:Class+Subclass", where
+//     any part of the string may be empty to represent a wildcard match.
+//   - device: A pointer to a `pci.Device` structure.
+//
+// Returns:
+//   - true:  If the device matches the filter criteria (wildcards are supported).
+//   - false: If the device does not match the filter criteria.
+//
+// Matching criteria:
+//   - VendorID must match `device.Vendor.ID` if provided.
+//   - ProductID must match `device.Product.ID` if provided.
+//   - Class and Subclass must match the concatenated result of `device.Class.ID` and `device.Subclass.ID` if provided.
+//
+// Example:
+//
+//	filter := "8086:1234:1200"
+//	device := pci.Device{Vendor: Vendor{ID: "8086"}, Product: Product{ID: "1234"}, Class: Class{ID: "12"}, Subclass: Subclass{ID: "00"}}
+//	isValid := validate(filter, &device)  // returns true
+//
+//	filter := "8086::1200"  // Wildcard for ProductID
+//	isValid := validate(filter, &device)  // returns true
+//
+//	filter := "::1200"  // Wildcard for ProductID and VendorID
+//	isValid := validate(filter, &device)  // returns true
+func validate(filter string, device *pci.Device) bool {
+	ids := strings.Split(filter, ":")
+
+	if (ids[0] == "" || ids[0] == device.Vendor.ID) &&
+		(len(ids) < 2 || (ids[1] == "" || ids[1] == device.Product.ID)) &&
+		(len(ids) < 3 || (ids[2] == "" || ids[2] == fmt.Sprintf("%s%s", device.Class.ID, device.Subclass.ID))) {
+		return true
+	}
+
+	return false
+}

pkg/accelerator/accelerator_linux_test.go

@@ -41,7 +41,7 @@ func testScenario(t *testing.T, filename string, expectedDevs int) {
 		_ = snapshot.Cleanup(tmpRoot)
 	}()
 
-	info, err := accelerator.New(option.WithChroot(tmpRoot))
+	info, err := accelerator.New([]string{}, option.WithChroot(tmpRoot))
 	if err != nil {
 		t.Fatalf("Expected nil err, but got %v", err)
 	}