contrib: add setup definition for virtio-venus device

Signed-off-by: Tonis Tiigi <[email protected]>

cmd/buildkitd/devices_venus.go

@@ -0,0 +1,8 @@
+//go:build venus
+// +build venus
+
+package main
+
+import (
+	_ "github.com/moby/buildkit/contrib/cdisetup/venus"
+)

contrib/cdisetup/venus/venus.go

@@ -0,0 +1,87 @@
+package venus
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"strings"
+
+	"github.com/moby/buildkit/solver/llbsolver/cdidevices"
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	cdiKind = "docker.com/gpu"
+)
+
+func init() {
+	cdidevices.Register(cdiKind, &setup{})
+}
+
+type setup struct {
+	version string
+}
+
+var _ cdidevices.Setup = &setup{}
+
+func (s *setup) Validate() error {
+	kVersion, err := getKernelVersion()
+	if err != nil {
+		return errors.Wrap(err, "failed to get kernel version")
+	}
+	if !strings.Contains(kVersion, "linuxkit") {
+		return errors.Errorf("%s currently requires a linuxkit kernel", cdiKind)
+	}
+
+	_, err = os.Stat("/dev/dri")
+	if err != nil {
+		if os.IsNotExist(err) {
+			return errors.Errorf("no DRI device found, make you use Docker VMM Hypervisor")
+		}
+		return errors.Wrap(err, "failed to check DRI device")
+	}
+
+	for _, dev := range []string{"renderD128", "card0"} {
+		if _, err := os.Stat("/dev/dri/" + dev); err != nil {
+			return errors.Wrapf(err, "failed to check DRI device %s", dev)
+		}
+	}
+	return nil
+}
+
+func (s *setup) Run(ctx context.Context) error {
+	if err := s.Validate(); err != nil {
+		return err
+	}
+
+	const dt = `cdiVersion: "0.6.0"
+kind: "docker.com/gpu"
+annotations:
+  cdi.device.name: "Virtio-GPU Venus (Docker Desktop)"
+devices:
+- name: venus
+  containerEdits:
+    deviceNodes:
+    - path: /dev/dri/card0
+    - path: /dev/dri/renderD128
+`
+
+	if err := os.MkdirAll("/etc/cdi", 0700); err != nil {
+		return errors.Wrap(err, "failed to create /etc/cdi")
+	}
+
+	if err := os.WriteFile("/etc/cdi/venus.yaml", []byte(dt), 0600); err != nil {
+		return errors.Wrap(err, "failed to write /etc/cdi/venus.yaml")
+	}
+
+	return nil
+}
+
+func getKernelVersion() (string, error) {
+	var uts unix.Utsname
+	if err := unix.Uname(&uts); err != nil {
+		return "", err
+	}
+	return string(uts.Release[:bytes.IndexByte(uts.Release[:], 0)]), nil
+}