feat(gpu): use aks-gpu-cuda-lts (R580 LTS) for the managed CUDA driver

parts/common/components.json

@@ -736,10 +736,10 @@
   ],
   "GPUContainerImages": [
     {
-      "downloadURL": "mcr.microsoft.com/aks/aks-gpu-cuda:*",
+      "downloadURL": "mcr.microsoft.com/aks/aks-gpu-cuda-lts:*",
       "gpuVersion": {
-        "renovateTag": "registry=https://mcr.microsoft.com, name=aks/aks-gpu-cuda",
-        "latestVersion": "580.126.09-20260126030251"
+        "renovateTag": "registry=https://mcr.microsoft.com, name=aks/aks-gpu-cuda-lts",
+        "latestVersion": "580.159.04-20260629214430"
       }
     },
     {

parts/linux/cloud-init/artifacts/acl/cse_install_acl.sh

@@ -175,7 +175,8 @@ installGPUDriverSysext() {
     #
     # NVIDIA_GPU_DRIVER_TYPE is set by AgentBaker based on the GPU SKU maps in
     # gpu_components.go. Converged sizes get "grid"; RTX PRO 6000 BSE v6 gets
-    # "grid-v20" (Ubuntu-only, rejected below); all others get "cuda".
+    # "grid-v20" (Ubuntu-only, rejected below); modern CUDA SKUs get "cuda-lts" and legacy
+    # NCv1 gets "cuda". Only grid vs non-grid matters here, so both take the CUDA path below.
     # Legacy GPUs (T4, V100) require proprietary CUDA drivers; A100+ use NVIDIA open drivers.
     local vm_sku
     vm_sku=$(get_compute_sku)

parts/linux/cloud-init/artifacts/cse_config.sh

@@ -1301,13 +1301,20 @@ validateGPUDrivers() {
 # before enabling consume. Observability only; no behavior change.
 logGPUDriverPrebakeReadiness() {
     local marker="${GPU_DKMS_MARKER_FILE:-/opt/azure/aks-gpu/dkms-marker}"
-    local marker_present=false driver_kind_match=false m_kind
+    local marker_present=false driver_kind_match=false m_kind node_kind
+    # Map the AgentBaker driver-type to the aks-gpu marker's driver_kind (the container's DRIVER_KIND
+    # build arg): image variants "cuda-lts" and "grid-v20" bake markers as "cuda"/"grid" respectively.
+    case "${NVIDIA_GPU_DRIVER_TYPE}" in
+        cuda*) node_kind=cuda ;;
+        grid*) node_kind=grid ;;
+        *) node_kind="${NVIDIA_GPU_DRIVER_TYPE}" ;;
+    esac
     if [ -f "${marker}" ]; then
         marker_present=true
         m_kind="$(sed -n 's/^driver_kind=//p' "${marker}" | head -n1)"
         # require both sides non-empty so a marker missing driver_kind= (or an unset
         # NVIDIA_GPU_DRIVER_TYPE) does not falsely report a match (empty = empty).
-        if [ -n "${m_kind}" ] && [ -n "${NVIDIA_GPU_DRIVER_TYPE}" ] && [ "${m_kind}" = "${NVIDIA_GPU_DRIVER_TYPE}" ]; then
+        if [ -n "${m_kind}" ] && [ -n "${node_kind}" ] && [ "${m_kind}" = "${node_kind}" ]; then
             driver_kind_match=true
         fi
     fi

parts/linux/cloud-init/artifacts/mariner/cse_install_mariner.sh

@@ -115,7 +115,8 @@ downloadGPUDrivers() {
     #
     # NVIDIA_GPU_DRIVER_TYPE is set by AgentBaker based on the GPU SKU maps in
     # gpu_components.go. Converged sizes get "grid"; RTX PRO 6000 BSE v6 gets
-    # "grid-v20" (Ubuntu-only, rejected below); all others get "cuda".
+    # "grid-v20" (Ubuntu-only, rejected below); modern CUDA SKUs get "cuda-lts" and legacy
+    # NCv1 gets "cuda". Only grid vs non-grid matters here, so both take the CUDA path below.
     # Legacy GPUs (T4, V100) require proprietary CUDA drivers; A100+ use NVIDIA open drivers.
     KERNEL_VERSION=$(uname -r | sed 's/-/./g')
     VM_SKU=$(get_compute_sku)

pkg/agent/baker.go

@@ -1525,14 +1525,23 @@ func GetAKSGPUImageSHA(size string) string {
 	return datamodel.AKSGPUCudaVersionSuffix
 }
 
+// GetGPUDriverType maps a GPU VM size to the aks-gpu image variant used to install its driver.
+// The value becomes NVIDIA_GPU_DRIVER_TYPE at provision time, which selects the container image
+// mcr.microsoft.com/aks/aks-gpu-<type>. Modern CUDA compute SKUs (T4, V100, A100, H100, H200, ...)
+// use the R580 LTS image (aks-gpu-cuda-lts): it retains Volta/V100 support that the newer aks-gpu-cuda
+// R595 line drops, is supported through Aug 2028, and is the branch the VHD driver prebake is built
+// against. Legacy NCv1 (K80) keeps the separate "cuda" path with its pinned R470 driver.
 func GetGPUDriverType(size string) string {
 	if useGridV20Drivers(size) {
 		return "grid-v20"
 	}
 	if useGridDrivers(size) {
 		return "grid"
 	}
-	return "cuda"
+	if isStandardNCv1(size) {
+		return "cuda"
+	}
+	return "cuda-lts"
 }
 
 func GPUNeedsFabricManager(size string) bool {

pkg/agent/baker_test.go

@@ -964,8 +964,11 @@ var _ = Describe("GetGPUDriverVersion", func() {
 
 var _ = Describe("GetGPUDriverType", func() {
 
-	It("should use cuda with nc v3", func() {
-		Expect(GetGPUDriverType("standard_nc6_v3")).To(Equal("cuda"))
+	It("should use cuda-lts with nc v3", func() {
+		Expect(GetGPUDriverType("standard_nc6_v3")).To(Equal("cuda-lts"))
+	})
+	It("should keep cuda (legacy R470) with nc v1 (K80)", func() {
+		Expect(GetGPUDriverType("standard_nc6")).To(Equal("cuda"))
 	})
 	It("should use grid with nv v5", func() {
 		Expect(GetGPUDriverType("standard_nv6ads_a10_v5")).To(Equal("grid"))
@@ -979,8 +982,8 @@ var _ = Describe("GetGPUDriverType", func() {
 		Expect(GetGPUDriverType("Standard_NC320lds_xl_RTXPRO6000BSE_v6")).To(Equal("grid-v20"))
 	})
 	// NV V1 SKUs were retired in September 2023, leaving this test just for safety
-	It("should use cuda with nv v1", func() {
-		Expect(GetGPUDriverType("standard_nv6")).To(Equal("cuda"))
+	It("should use cuda-lts with nv v1", func() {
+		Expect(GetGPUDriverType("standard_nv6")).To(Equal("cuda-lts"))
 	})
 })
 
@@ -1118,7 +1121,7 @@ var _ = Describe("getLinuxNodeCSECommand", func() {
 		vars := decodeCSEVars(cseCmd)
 		Expect(vars).To(HaveKeyWithValue("GPU_NODE", "true"))
 		Expect(vars).To(HaveKeyWithValue("CONFIG_GPU_DRIVER_IF_NEEDED", "true"))
-		Expect(vars).To(HaveKeyWithValue("GPU_DRIVER_TYPE", "cuda"))
+		Expect(vars).To(HaveKeyWithValue("GPU_DRIVER_TYPE", "cuda-lts"))
 	})
 
 	It("should handle custom cloud environment", func() {

pkg/agent/datamodel/gpu_components.go

@@ -62,7 +62,7 @@ func LoadConfig() error {
 		// repos sharing a prefix (e.g. "aks-gpu-grid" vs "aks-gpu-grid-v20") are not
 		// confused by substring matching.
 		switch gpuImageRepo(image.DownloadURL) {
-		case "aks-gpu-cuda":
+		case "aks-gpu-cuda-lts":
 			NvidiaCudaDriverVersion = version
 			AKSGPUCudaVersionSuffix = suffix
 		case "aks-gpu-grid":

pkg/agent/datamodel/gpu_components_test.go

@@ -71,7 +71,7 @@ func TestLoadConfig(t *testing.T) {
 // LoadConfig switch that maps each repo to its own driver version/suffix.
 func TestGPUImageRepo(t *testing.T) {
 	cases := map[string]string{
-		"mcr.microsoft.com/aks/aks-gpu-cuda:*":               "aks-gpu-cuda",
+		"mcr.microsoft.com/aks/aks-gpu-cuda-lts:*":           "aks-gpu-cuda-lts",
 		"mcr.microsoft.com/aks/aks-gpu-grid:*":               "aks-gpu-grid",
 		"mcr.microsoft.com/aks/aks-gpu-grid-v20:*":           "aks-gpu-grid-v20",
 		"mcr.microsoft.com/aks/aks-gpu-grid-v20:595.58.03-1": "aks-gpu-grid-v20",

spec/parts/linux/cloud-init/artifacts/cse_config_spec.sh

@@ -39,6 +39,18 @@ Describe 'cse_config.sh'
             rm -f "$marker"
         End
 
+        It 'matches a cuda marker for a cuda-lts (R580 LTS) node: driver-type maps to the aks-gpu driver_kind'
+            marker="$(mktemp)"
+            printf 'driver_kind=cuda\n' > "$marker"
+            GPU_DKMS_MARKER_FILE="$marker"
+            NVIDIA_GPU_DRIVER_TYPE="cuda-lts"
+            When call logGPUDriverPrebakeReadiness
+            The output should include "marker_present=true"
+            The output should include "driver_kind_match=true"
+            The output should include "driver_type=cuda-lts"
+            rm -f "$marker"
+        End
+
         It 'reports driver_kind_match=false when a CUDA marker is on a GRID node (not skip-ready)'
             marker="$(mktemp)"
             printf 'driver_kind=cuda\n' > "$marker"

vhdbuilder/packer/install-dependencies.sh

@@ -716,7 +716,7 @@ if [ $OS = $UBUNTU_OS_NAME ] && [ "$(isARM64)" -ne 1 ]; then  # No ARM64 SKU wit
     # shellcheck disable=SC2001
     imageName=$(echo "$downloadURL" | sed 's/:.*$//')
 
-    if [ "$imageName" = "mcr.microsoft.com/aks/aks-gpu-cuda" ]; then
+    if [ "$imageName" = "mcr.microsoft.com/aks/aks-gpu-cuda-lts" ]; then
       latestVersion=$(echo "${imageToBePulled}" | jq -r '.gpuVersion.latestVersion')
       NVIDIA_DRIVER_IMAGE="$imageName"
       NVIDIA_DRIVER_IMAGE_TAG="$latestVersion"
@@ -726,7 +726,7 @@ if [ $OS = $UBUNTU_OS_NAME ] && [ "$(isARM64)" -ne 1 ]; then  # No ARM64 SKU wit
 
   # Check if the NVIDIA_DRIVER_IMAGE and NVIDIA_DRIVER_IMAGE_TAG were found
   if [ -z "$NVIDIA_DRIVER_IMAGE" ] || [ -z "$NVIDIA_DRIVER_IMAGE_TAG" ]; then
-    echo "Error: Unable to find aks-gpu-cuda image in components.json"
+    echo "Error: Unable to find aks-gpu-cuda-lts image in components.json"
     exit 1
   fi