[Docs] Add AMD-specific HiCache config for DeepSeek V4 playground (#31122)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

docs_new/cookbook/autoregressive/DeepSeek/DeepSeek-V4.mdx

@@ -514,6 +514,10 @@ To enable HiCache, open the **HiCache** card in the [Playground above](#playgrou
 - **L2 (GPU + CPU)** — leave Storage on `auto` (default). Cold KV pages spill to CPU pinned memory only.
 - **L3 (GPU + CPU + Storage)** — pick a Storage backend (`file` / `mooncake` / `hf3fs` / `nixl`); the Playground emits the canonical `page_first_direct` mem-layout + `direct` IO backend + `wait_complete` prefetch policy, matching the [HiCache best-practices recipe](../../../docs/advanced_features/hicache_best_practices).
 
+For AMD devices,
+- **L2 (GPU + CPU)** — leave Storage on `auto` (default). Cold KV pages spill to CPU pinned memory only. Use `direct` IO backend + `page_first_direct` or `layer-first` mem-layout.
+- **L3 (GPU + CPU + Storage)** — pick a Storage backend (`file`); the Playground emits the canonical `page_first_direct` mem-layout + `direct` IO backend + `wait_complete` prefetch policy, matching the [HiCache best-practices recipe](../../../docs/advanced_features/hicache_best_practices).
+
 The Write policy knob defaults to `write_through` (the upstream default); switch to `write_back` / `write_through_selective` to trade durability for write speed when the storage tier is slow.
 
 For more details, see the [HiCache documentation](../../../docs/advanced_features/hicache).

docs_new/src/snippets/_playground.jsx

@@ -1014,19 +1014,31 @@ export const Playground = ({ config }) => {
           "--hicache-storage-backend", "--hicache-storage-prefetch-policy",
         ]);
         if (value.enable) {
+          const isAmd = sel && /^mi\d/.test(sel.hw);
+          const ratio = (isAmd && fc.amdIo && fc.amdIo.ratio) || 2;
+          const useAmdIo = isAmd && fc.amdIo;
           const adds = [
             "--enable-hierarchical-cache",
-            "--hicache-ratio 2",
-            "--hicache-size 0",
+            `--hicache-ratio ${ratio}`,
           ];
-          if (value.backend) {
+          if (!useAmdIo) {
+            adds.push("--hicache-size 0");
+          }
+          // Per-model configs can declare fc.amdIo = { memLayout, ioBackend, ratio }
+          // for AMD ROCm overrides (e.g. page_first_direct + direct on MI355X).
+          // Default (NVIDIA): page_first_direct + direct, ratio 2.
+          if (useAmdIo) {
+            adds.push(`--hicache-mem-layout ${fc.amdIo.memLayout}`,
+                      `--hicache-io-backend ${fc.amdIo.ioBackend}`);
+          } else if (value.backend) {
             adds.push("--hicache-mem-layout page_first_direct",
                       "--hicache-io-backend direct");
           }
           const writePolicy = (value.writePolicy && value.writePolicy !== "auto")
             ? value.writePolicy : "write_through";
           adds.push(`--hicache-write-policy ${writePolicy}`);
-          if (value.backend) {
+          // When amdStorageFileOnly is set, AMD emits storage flags only for "file".
+          if ((isAmd && fc.amdStorageFileOnly) ? value.backend === "file" : !!value.backend) {
             adds.push(`--hicache-storage-backend ${value.backend}`,
                       "--hicache-storage-prefetch-policy wait_complete");
           }

docs_new/src/snippets/configs/deepseek-ai/deepseek-v4.jsx

@@ -323,12 +323,18 @@ sgl-eval run aime25 \\
     // ----- Card 6: "Hierarchical KV Cache" -----
     hicache: {
       excludesHw: ["rtx6000"],
+      // AMD ROCm (MI300X/MI325X/MI350X/MI355X): page_first_direct + direct io.
+      amdIo: { memLayout: "page_first_direct", ioBackend: "direct", ratio: 4 },
+      amdStorageFileOnly: true,
       backends: [
         { id: null,        label: "Auto" },
         { id: "file",      label: "File" },
-        { id: "mooncake",  label: "Mooncake" },
-        { id: "hf3fs",     label: "HF3FS" },
-        { id: "nixl",      label: "NiXL" },
+        { id: "mooncake",  label: "Mooncake",
+          hide: { hw: ["mi300x", "mi355x"] } },
+        { id: "hf3fs",     label: "HF3FS",
+          hide: { hw: ["mi300x", "mi355x"] } },
+        { id: "nixl",      label: "NiXL",
+          hide: { hw: ["mi300x", "mi355x"] } },
       ],
       writePolicies: [
         { id: "auto",                    label: "Auto" },