Vulkan k-quant mmq and ggml-backend offload functionality (#6155)

* Fix Vulkan no kv offload incoherence

* Add k-quant mul mat mat shaders

* Rework working buffer allocation, reduces vram use noticeably

Clean up cpu assist code, replaced with ggml-backend offload function

* Default to all dedicated GPUs

* Add fallback for integrated GPUs if no dedicated GPUs are found

* Add debug info which device is allocating memory

* Fix Intel dequant issue

Fix validation issue

* Fix Vulkan GGML_OP_GET_ROWS implementation

* Clean up merge artifacts

* Remove Vulkan warning

1 files changed, 14 insertions, 5 deletions

diff --git a/llama.cpp b/llama.cpp
index 97408ba1..21e7a067 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -2121,10 +2121,6 @@ struct llama_context {
             ggml_backend_free(backend);
         }
 
-#ifdef GGML_USE_VULKAN
-        ggml_vk_free_cpu_assist();
-#endif
-
         ggml_backend_buffer_free(buf_output);
     }
 
@@ -14131,7 +14127,20 @@ struct llama_context * llama_new_context_with_model(
             }
         }
 #elif defined(GGML_USE_VULKAN)
-        if (model->n_gpu_layers > 0) {
+        if (model->split_mode == LLAMA_SPLIT_MODE_ROW) {
+            LLAMA_LOG_ERROR("%s: Row split not supported. Failed to initialize Vulkan backend\n", __func__);
+            llama_free(ctx);
+            return nullptr;
+        }
+        if (model->split_mode == LLAMA_SPLIT_MODE_NONE) {
+            ggml_backend_t backend = ggml_backend_vk_init(0);
+            if (backend == nullptr) {
+                LLAMA_LOG_ERROR("%s: failed to initialize Vulkan backend\n", __func__);
+                llama_free(ctx);
+                return nullptr;
+            }
+            ctx->backends.push_back(backend);
+        } else {
             for (int device = 0; device < ggml_backend_vk_get_device_count(); ++device) {
                 ggml_backend_t backend = ggml_backend_vk_init(device);
                 if (backend == nullptr) {