virglrenderer: add virgl_renderer_execute

It's desirable to query or modify virgl_renderer state for various values.

We've done it for resources (virgl_renderer_get_fd_for_texture /
virgl_renderer_get_fd_for_texture2 / virgl_renderer_resource_get_info) a
few times, but more parameters are often desired.

Let's define a protocol instead.  That way, more queries/operations (is "ctx
{num} lost?", "is x host feature supported?") can be formulated.

It's also possible to put the protocol in virgl_hw.h, so in theory
the guest can recieve a response directly from virglrenderer. Any
opinions on this?

v2: virgl_renderer_query --> virgl_renderer_execute

Reviewed-by: David Riley <davidriley@chromium.org>
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/virgl_gbm.c

@@ -368,3 +368,62 @@ uint32_t virgl_gbm_convert_flags(uint32_t virgl_bind_flags)
       flags |= GBM_BO_USE_CURSOR;
    return flags;
 }
+
+int virgl_gbm_export_query(struct gbm_bo *bo, struct virgl_renderer_export_query *query)
+{
+   int ret = -1;
+   uint32_t handles[4] = {0, 0, 0, 0};
+   struct gbm_device *gbm = gbm_bo_get_device(bo);
+   int num_planes = gbm_bo_get_plane_count(bo);
+   if (num_planes < 0 || num_planes > 4)
+      return ret;
+
+   query->out_num_fds = 0;
+   query->out_fourcc = 0;
+   query->out_modifier = 0;
+   for (int plane = 0; plane < 4; plane++) {
+      query->out_fds[plane] = -1;
+      query->out_strides[plane] = 0;
+      query->out_offsets[plane] = 0;
+   }
+
+   for (int plane = 0; plane < num_planes; plane++) {
+      uint32_t i, handle;
+      query->out_strides[plane] = gbm_bo_get_stride_for_plane(bo, plane);
+      query->out_offsets[plane] = gbm_bo_get_offset(bo, plane);
+      handle = gbm_bo_get_handle_for_plane(bo, plane).u32;
+
+      for (i = 0; i < query->out_num_fds; i++) {
+         if (handles[query->out_num_fds] == handle)
+            break;
+      }
+
+      if (i == query->out_num_fds) {
+         if (query->in_export_fds) {
+            ret = drmPrimeHandleToFD(gbm_device_get_fd(gbm), handle, DRM_CLOEXEC,
+                                     &query->out_fds[query->out_num_fds]);
+            if (ret)
+               goto err_close;
+         }
+         query->out_num_fds++;
+      }
+   }
+
+   query->out_modifier = gbm_bo_get_modifier(bo);
+   query->out_fourcc = gbm_bo_get_format(bo);
+   return 0;
+
+err_close:
+   for (int plane = 0; plane < 4; plane++) {
+      if (query->out_fds[plane] >= 0) {
+         close(query->out_fds[plane]);
+         query->out_fds[plane] = -1;
+      }
+
+      query->out_strides[plane] = 0;
+      query->out_offsets[plane] = 0;
+   }
+
+   query->out_num_fds = 0;
+   return ret;
+}

src/virgl_gbm.h

@@ -27,6 +27,7 @@
 
 #include <gbm.h>
 #include "vrend_iov.h"
+#include "virglrenderer.h"
 
 /*
  * If fd >= 0, virglrenderer owns the fd since it was opened via a rendernode
@@ -49,4 +50,6 @@ int virgl_gbm_transfer(struct gbm_bo *bo, uint32_t direction, struct iovec *iove
 
 uint32_t virgl_gbm_convert_flags(uint32_t virgl_bind_flags);
 
+int virgl_gbm_export_query(struct gbm_bo *bo, struct virgl_renderer_export_query *query);
+
 #endif

src/virglrenderer.c

@@ -422,3 +422,8 @@ virgl_debug_callback_type virgl_set_debug_callback(virgl_debug_callback_type cb)
 {
    return vrend_set_debug_callback(cb);
 }
+
+int virgl_renderer_execute(void *execute_args, uint32_t execute_size)
+{
+   return vrend_renderer_execute(execute_args, execute_size);
+}

src/virglrenderer.h

@@ -98,6 +98,11 @@ VIRGL_EXPORT int virgl_renderer_get_fd_for_texture2(uint32_t tex_id, int *fd, in
 #define VIRGL_RES_BIND_SCANOUT       (1 << 18)
 #define VIRGL_RES_BIND_SHARED        (1 << 20)
 
+enum virgl_renderer_structure_type_v0 {
+   VIRGL_RENDERER_STRUCTURE_TYPE_NONE = 0x00000000,
+   VIRGL_RENDERER_STRUCTURE_TYPE_EXPORT_QUERY = 0x00000001,
+};
+
 struct virgl_renderer_resource_create_args {
    uint32_t handle;
    uint32_t target;
@@ -112,6 +117,33 @@ struct virgl_renderer_resource_create_args {
    uint32_t flags;
 };
 
+struct virgl_renderer_hdr {
+   uint32_t stype;
+   uint32_t stype_version;
+   uint32_t size;
+};
+
+/*
+ * "out_num_fds" represents the number of distinct kernel buffers backing an
+ * allocation. If this number or 'out_fourcc' is zero, the resource is not
+ * exportable. The "out_fds" field will be populated with "out_num_fds" file
+ * descriptors if "in_export_fds" is non-zero.
+ */
+struct virgl_renderer_export_query {
+   struct virgl_renderer_hdr hdr;
+   uint32_t in_resource_id;
+
+   uint32_t out_num_fds;
+   uint32_t in_export_fds;
+   uint32_t out_fourcc;
+   uint32_t pad;
+
+   int32_t out_fds[4];
+   uint32_t out_strides[4];
+   uint32_t out_offsets[4];
+   uint64_t out_modifier;
+};
+
 /* new API */
 /* This typedef must be kept in sync with vrend_debug.h */
 typedef void (*virgl_debug_callback_type)(const char *fmt, va_list ap);
@@ -190,4 +222,6 @@ VIRGL_EXPORT void virgl_renderer_reset(void);
 
 VIRGL_EXPORT int virgl_renderer_get_poll_fd(void);
 
+VIRGL_EXPORT int virgl_renderer_execute(void *execute_args, uint32_t execute_size);
+
 #endif

src/vrend_renderer.c

@@ -50,6 +50,7 @@
 #include "vrend_debug.h"
 
 #include "virgl_hw.h"
+#include "virglrenderer.h"
 
 #include "tgsi/tgsi_text.h"
 
@@ -9625,6 +9626,7 @@ void *vrend_renderer_get_cursor_contents(uint32_t res_handle, uint32_t *width, u
    return data2;
 }
 
+
 void vrend_renderer_force_ctx_0(void)
 {
    struct vrend_context *ctx0 = vrend_lookup_renderer_ctx(0);
@@ -9922,3 +9924,39 @@ int vrend_renderer_get_poll_fd(void)
 
    return vrend_state.eventfd;
 }
+
+int vrend_renderer_execute(void *execute_args, uint32_t execute_size)
+{
+   /*
+    * This function only supports VIRGL_RENDERER_STRUCTURE_TYPE_RESOURCE_QUERY currently.
+    */
+   struct vrend_resource *res;
+   struct virgl_renderer_export_query *export_query = execute_args;
+   if (execute_size != sizeof(struct virgl_renderer_export_query))
+      return -EINVAL;
+
+   if (export_query->hdr.stype != VIRGL_RENDERER_STRUCTURE_TYPE_EXPORT_QUERY ||
+       export_query->hdr.stype_version != 0 ||
+       export_query->hdr.size != sizeof(struct virgl_renderer_export_query))
+      return -EINVAL;
+
+   res = vrend_resource_lookup(export_query->in_resource_id, 0);
+   if (!res)
+      return -EINVAL;
+
+#ifdef ENABLE_GBM_ALLOCATION
+   if (res->gbm_bo)
+      return virgl_gbm_export_query(res->gbm_bo, export_query);
+#endif
+
+   /*
+    * Implementations that support eglExportDMABUFImageMESA can also export certain resources.
+    * This is omitted currently since virgl_renderer_get_fd_for_texture supports that use case.
+    */
+   export_query->out_num_fds = 0;
+   export_query->out_fourcc = 0;
+   if (export_query->in_export_fds)
+      return -EINVAL;
+
+   return 0;
+}

src/vrend_renderer.h

@@ -452,4 +452,7 @@ static const struct gl_version gl_versions[] = { {4,5}, {4,4}, {4,3}, {4,2}, {4,
                                                  {3,3}, {3,2}, {3,1}, {3,0} };
 
 extern struct vrend_if_cbs *vrend_clicbs;
+
+int vrend_renderer_execute(void *execute_args, uint32_t execute_size);
+
 #endif