asahi: translate the retained G15 wire under virtio

src/asahi/lib/agx_device.c

@@ -933,8 +933,15 @@ agx_open_device(void *memctx, struct agx_device *dev)
 
    uint64_t normalized_features;
    dev->g15_legacy_wire = false;
-   if (!dev->is_virtio &&
-       agx_g15_wire_features(&dev->params, &normalized_features)) {
+   if (agx_g15_wire_features(&dev->params, &normalized_features)) {
+      /* Under virtio the host renderer forwards GET_PARAMS and SUBMIT to the
+       * same retained G15 kernel, so the guest needs the same feature
+       * normalization and packet translation. virglrenderer only forwards
+       * param group 0, and the VM status paths issue raw asahi ioctls on the
+       * guest fd, so the guest must not advertise them. */
+      if (dev->is_virtio)
+         normalized_features &= ~(uint64_t)(DRM_ASAHI_FEATURE_VM_STATUS |
+                                            DRM_ASAHI_FEATURE_VM_STATUS_MIRROR);
       dev->g15_legacy_wire = true;
       dev->params.features = normalized_features;
    }

src/asahi/lib/agx_device_virtio.c

@@ -4,7 +4,9 @@
  */
 
 #include "agx_device_virtio.h"
+#include "agx_g15_wire.h"
 
+#include <errno.h>
 #include <inttypes.h>
 #include <sys/mman.h>
 
@@ -240,14 +242,33 @@ agx_virtio_submit(struct agx_device *dev, struct drm_asahi_submit *submit,
 
    struct asahi_ccmd_submit_req *req =
       (struct asahi_ccmd_submit_req *)calloc(1, req_len);
+   if (!req) {
+      errno = ENOMEM;
+      return -1;
+   }
 
    req->queue_id = submit->queue_id;
    req->extres_count = virt->extres_count;
    req->cmdbuf_size = submit->cmdbuf_size;
 
    char *ptr = (char *)&req->payload;
 
-   memcpy(ptr, (void *)(uintptr_t)submit->cmdbuf, req->cmdbuf_size);
+   if (dev->g15_legacy_wire) {
+      /* The retained G15 wire is never larger than the canonical input, so
+       * translate straight into the request and shrink it to fit. */
+      size_t packed;
+      if (!agx_g15_wire_pack((void *)(uintptr_t)submit->cmdbuf,
+                             submit->cmdbuf_size, ptr, submit->cmdbuf_size,
+                             &packed)) {
+         free(req);
+         errno = EINVAL;
+         return -1;
+      }
+      req->cmdbuf_size = packed;
+      req_len = sizeof(struct asahi_ccmd_submit_req) + packed + extres_size;
+   } else {
+      memcpy(ptr, (void *)(uintptr_t)submit->cmdbuf, req->cmdbuf_size);
+   }
    ptr += req->cmdbuf_size;
 
    memcpy(ptr, virt->extres, extres_size);