ggml-virtgpu: make the code thread safe (#19204)

* ggml-virtgpu: regenerate_remoting.py: add the ability to deprecate a function

* ggml-virtgpu: deprecate buffer_type is_host remoting

not necessary

* ggml-virtgpu: stop using static vars as cache

The static init isn't thread safe.

* ggml-virtgpu: protect the use of the shared memory to transfer data

* ggml-virtgpu: make the remote calls thread-safe

* ggml-virtgpu: backend: don't continue if couldn't allocate the tensor memory

* ggml-virtgpu: add a cleanup function for consistency

* ggml-virtgpu: backend: don't crash if buft->iface.get_max_size is missing

* fix style and ordering

* Remove the static variable in apir_device_get_count

* ggml-virtgpu: improve the logging

* fix review minor formatting changes

ggml/src/ggml-virtgpu/virtgpu.h

@@ -17,6 +17,8 @@
 
 #include <cstring>
 
+#include "ggml-remoting.h"
+
 #define VIRGL_RENDERER_UNSTABLE_APIS 1
 #include "apir_hw.h"
 #include <drm/virtgpu_drm.h>
@@ -73,6 +75,27 @@ struct virtgpu {
     /* APIR communication pages */
     virtgpu_shmem reply_shmem;
     virtgpu_shmem data_shmem;
+
+    /* Mutex to protect shared data_shmem buffer from concurrent access */
+    mtx_t data_shmem_mutex;
+
+    /* Cached device information to prevent memory leaks and race conditions */
+    struct {
+        char *   description;
+        char *   name;
+        int32_t  device_count;
+        uint32_t type;
+        size_t   memory_free;
+        size_t   memory_total;
+    } cached_device_info;
+
+    /* Cached buffer type information to prevent memory leaks and race conditions */
+    struct {
+        apir_buffer_type_host_handle_t host_handle;
+        char *                         name;
+        size_t                         alignment;
+        size_t                         max_size;
+    } cached_buffer_type;
 };
 
 static inline int virtgpu_ioctl(virtgpu * gpu, unsigned long request, void * args) {