From: Honglei Huang <honghuan@amd.com>

Unify error checking style for virtio_gpu_create_mapping_iov() across the
codebase to improve consistency and readability.

virtio_gpu_create_mapping_iov() returns 0 on success and negative values
on error. The original code used inconsistent patterns for checking errors:
- Some used 'if (ret != 0)' in virtio-gpu-virgl.c and virtio-gpu.c
- Some used 'CHECK(!ret, cmd)' in virtio-gpu-rutabaga.c

For if-statement checks, change to 'if (ret < 0)' which is the preferred
QEMU coding convention for functions that return 0 on success and negative
on error. This makes the return value convention immediately clear to code
readers.

For CHECK macro usage in virtio-gpu-rutabaga.c, keep the original
'CHECK(!ret, cmd)' pattern as it is more concise and consistent with other
error checks in the same file.

Updated locations:
- hw/display/virtio-gpu-virgl.c: virgl_resource_attach_backing()
- hw/display/virtio-gpu-virgl.c: virgl_cmd_resource_create_blob()
- hw/display/virtio-gpu.c: virtio_gpu_resource_create_blob()
- hw/display/virtio-gpu.c: virtio_gpu_resource_attach_backing()

Signed-off-by: Honglei Huang <honghuan@amd.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260113015203.3643608-3-honghuan@amd.com>
---
 hw/display/virtio-gpu-virgl.c | 4 ++--
 hw/display/virtio-gpu.c       | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
index 741728cabb..ecf8494f36 100644
--- a/hw/display/virtio-gpu-virgl.c
+++ b/hw/display/virtio-gpu-virgl.c
@@ -561,7 +561,7 @@ static void virgl_resource_attach_backing(VirtIOGPU *g,
 
     ret = virtio_gpu_create_mapping_iov(g, att_rb.nr_entries, sizeof(att_rb),
                                         cmd, NULL, &res_iovs, &res_niov);
-    if (ret != 0) {
+    if (ret < 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         return;
     }
@@ -705,7 +705,7 @@ static void virgl_cmd_resource_create_blob(VirtIOGPU *g,
         ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
                                             cmd, &res->base.addrs,
                                             &res->base.iov, &res->base.iov_cnt);
-        if (ret != 0) {
+        if (ret < 0) {
             cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
             return;
         }
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index f23eec6862..643e91ca2a 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -354,7 +354,7 @@ static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
     ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
                                         cmd, &res->addrs, &res->iov,
                                         &res->iov_cnt);
-    if (ret != 0) {
+    if (ret < 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         g_free(res);
         return;
@@ -933,7 +933,7 @@ virtio_gpu_resource_attach_backing(VirtIOGPU *g,
 
     ret = virtio_gpu_create_mapping_iov(g, ab.nr_entries, sizeof(ab), cmd,
                                         &res->addrs, &res->iov, &res->iov_cnt);
-    if (ret != 0) {
+    if (ret < 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         return;
     }
-- 
MST