feat(admission): add NvFractions request validation foundation

Signed-off-by: davidLif <davidshani12@gmail.com>

Author: davidLif

.changes/unreleased/added-20260810-110000.yaml

@@ -0,0 +1,3 @@
+kind: Added
+body: |-
+  Validate NvFractions GPU memory annotations

pkg/admission/webhook/v1alpha2/gpusharing/gpu_sharing.go

@@ -6,19 +6,20 @@ package gpusharing
 import (
 	"fmt"
 
+	"strconv"
+
 	v1 "k8s.io/api/core/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	"github.com/kai-scheduler/KAI-scheduler/pkg/binder/common/gpusharingconfigmap"
+	"github.com/kai-scheduler/KAI-scheduler/pkg/common/constants"
 	"github.com/kai-scheduler/KAI-scheduler/pkg/common/resources"
 
 	"github.com/kai-scheduler/KAI-scheduler/pkg/binder/common"
-	gpurequesthandler "github.com/kai-scheduler/KAI-scheduler/pkg/binder/plugins/gpusharing/gpu-request"
 )
 
 const (
-	fractionContainerIndex = 0
-	CdiDeviceNameBase      = "k8s.device-plugin.nvidia.com/gpu=%s"
+	CdiDeviceNameBase = "k8s.device-plugin.nvidia.com/gpu=%s"
 )
 
 type GPUSharing struct {
@@ -44,7 +45,7 @@ func (p *GPUSharing) Validate(pod *v1.Pod) error {
 			pod.Namespace, pod.Name,
 		)
 	}
-	return gpurequesthandler.ValidateGpuRequests(pod)
+	return resources.ValidateGPUFractionRequest(pod)
 }
 
 func (p *GPUSharing) Mutate(pod *v1.Pod) error {
@@ -61,6 +62,11 @@ func (p *GPUSharing) Mutate(pod *v1.Pod) error {
 		return fmt.Errorf("failed to get fraction container ref: %w", err)
 	}
 
+	err = adjustFractionalMemoryAnnotations(pod, containerRef)
+	if err != nil {
+		return err
+	}
+
 	capabilitiesConfigMapName := gpusharingconfigmap.SetGpuCapabilitiesConfigMapName(pod, containerRef)
 	directEnvVarsMapName, err := gpusharingconfigmap.ExtractDirectEnvVarsConfigMapName(pod, containerRef)
 	if err != nil {
@@ -73,3 +79,17 @@ func (p *GPUSharing) Mutate(pod *v1.Pod) error {
 
 	return nil
 }
+
+// adjustFractionalMemoryAnnotations adjusts the old fractional memory annotations to NvFractions format
+func adjustFractionalMemoryAnnotations(pod *v1.Pod, containerRef *gpusharingconfigmap.PodContainerRef) error {
+	gpuMemoryRequestMiB, foundGPUMemory := pod.Annotations[constants.GpuMemory]
+	if foundGPUMemory {
+		gpuMemoryRequestMiB, err := strconv.ParseUint(gpuMemoryRequestMiB, 10, 64)
+		if err != nil {
+			return fmt.Errorf("failed to parse gpu memory annotation value: %w", err)
+		}
+		memoryQuantity := resources.GpuMemoryAnnotationToNvFractionsMemoryRequest(gpuMemoryRequestMiB)
+		pod.Annotations[resources.CalcGpuFractionAnnotationForContainer(containerRef.Container.Name)] = memoryQuantity.String()
+	}
+	return nil
+}