diff --git a/src/virgl_context.h b/src/virgl_context.h
index 92628be..879618d 100644
--- a/src/virgl_context.h
+++ b/src/virgl_context.h
@@ -25,6 +25,7 @@
 #ifndef VIRGL_CONTEXT_H
 #define VIRGL_CONTEXT_H
 
+#include <stddef.h>
 #include <stdint.h>
 
 struct virgl_context {
@@ -36,6 +37,10 @@ struct virgl_context {
                            uint32_t res_id);
    void (*detach_resource)(struct virgl_context *ctx,
                            uint32_t res_id);
+
+   int (*submit_cmd)(struct virgl_context *ctx,
+                     const void *buffer,
+                     size_t size);
 };
 
 int
diff --git a/src/virglrenderer.c b/src/virglrenderer.c
index 5d37c71..955ea87 100644
--- a/src/virglrenderer.c
+++ b/src/virglrenderer.c
@@ -101,7 +101,10 @@ int virgl_renderer_submit_cmd(void *buffer,
                               int ctx_id,
                               int ndw)
 {
-   return vrend_decode_block(ctx_id, buffer, ndw);
+   struct virgl_context *ctx = virgl_context_lookup(ctx_id);
+   if (!ctx)
+      return EINVAL;
+   return ctx->submit_cmd(ctx, buffer, sizeof(uint32_t) * ndw);
 }
 
 int virgl_renderer_transfer_write_iov(uint32_t handle,
diff --git a/src/vrend_decode.c b/src/vrend_decode.c
index 5b79670..e8e1345 100644
--- a/src/vrend_decode.c
+++ b/src/vrend_decode.c
@@ -1469,25 +1469,20 @@ static void vrend_decode_ctx_detach_resource(struct virgl_context *ctx,
    vrend_renderer_detach_res_ctx(dctx->grctx, res_id);
 }
 
-int vrend_decode_block(uint32_t ctx_id, uint32_t *block, int ndw)
+static int vrend_decode_ctx_submit_cmd(struct virgl_context *ctx,
+                                       const void *buffer,
+                                       size_t size)
 {
-   struct vrend_decode_ctx *gdctx;
+   struct vrend_decode_ctx *gdctx = (struct vrend_decode_ctx *)ctx;
    bool bret;
    int ret;
 
-   if (ctx_id == 0)
-      return EINVAL;
-
-   gdctx = vrend_decode_ctx_lookup(ctx_id);
-   if (!gdctx)
-      return EINVAL;
-
    bret = vrend_hw_switch_context(gdctx->grctx, true);
    if (bret == false)
       return EINVAL;
 
-   gdctx->ds->buf = block;
-   gdctx->ds->buf_total = ndw;
+   gdctx->ds->buf = buffer;
+   gdctx->ds->buf_total = size / sizeof(uint32_t);
    gdctx->ds->buf_offset = 0;
 
    while (gdctx->ds->buf_offset < gdctx->ds->buf_total) {
@@ -1632,7 +1627,7 @@ int vrend_decode_block(uint32_t ctx_id, uint32_t *block, int ndw)
          ret = vrend_decode_get_query_result_qbo(gdctx, len);
          break;
       case VIRGL_CCMD_TRANSFER3D:
-         ret = vrend_decode_transfer3d(gdctx, len, ctx_id);
+         ret = vrend_decode_transfer3d(gdctx, len, gdctx->base.ctx_id);
          break;
       case VIRGL_CCMD_COPY_TRANSFER3D:
          ret = vrend_decode_copy_transfer3d(gdctx, len);
@@ -1669,6 +1664,7 @@ static void vrend_decode_ctx_init_base(struct vrend_decode_ctx *dctx,
    ctx->destroy = vrend_decode_ctx_destroy;
    ctx->attach_resource = vrend_decode_ctx_attach_resource;
    ctx->detach_resource = vrend_decode_ctx_detach_resource;
+   ctx->submit_cmd = vrend_decode_ctx_submit_cmd;
 }
 
 void vrend_decode_reset(bool ctx_0_only)
diff --git a/src/vrend_renderer.h b/src/vrend_renderer.h
index c2eef18..b8da54d 100644
--- a/src/vrend_renderer.h
+++ b/src/vrend_renderer.h
@@ -332,7 +332,6 @@ void vrend_set_tess_state(struct vrend_context *ctx, const float tess_factors[6]
 
 void vrend_renderer_fini(void);
 
-int vrend_decode_block(uint32_t ctx_id, uint32_t *block, int ndw);
 struct vrend_context *vrend_lookup_renderer_ctx(uint32_t ctx_id);
 
 int vrend_renderer_create_fence(int client_fence_id, uint32_t ctx_id);