drm/virtio: support VIRTIO_GPU_F_BLOB_ALIGNMENT

Support VIRTIO_GPU_F_BLOB_ALIGNMENT, a feature that indicates the device
provides a valid blob_alignment field in its configuration, and that
both RESOURCE_CREATE_BLOB and RESOURCE_MAP_BLOB requests must be aligned
to that value.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patch.msgid.link/20260428194450.518296-2-slp@redhat.com

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index a5ce96fb8a1d24cff29c00706637834dc214c95e..812ee3f5e4aa90b3facb3611280c47e676477141 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -163,6 +163,7 @@ static unsigned int features[] = {
        VIRTIO_GPU_F_RESOURCE_UUID,
        VIRTIO_GPU_F_RESOURCE_BLOB,
        VIRTIO_GPU_F_CONTEXT_INIT,
+       VIRTIO_GPU_F_BLOB_ALIGNMENT,
 };
 static struct virtio_driver virtio_gpu_driver = {
        .feature_table = features,

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 6f49213e23f8ee3afe78f29bed52239ccd1d194c..04fe15d877cd3a13a242c0b0ec3f6ff08363185d 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -258,6 +258,7 @@ struct virtio_gpu_device {
        bool has_resource_blob;
        bool has_host_visible;
        bool has_context_init;
+       bool has_blob_alignment;
        struct virtio_shm_region host_visible_region;
        struct drm_mm host_visible_mm;
 
@@ -271,6 +272,7 @@ struct virtio_gpu_device {
        uint32_t num_capsets;
        uint64_t capset_id_mask;
        struct list_head cap_cache;
+       uint32_t blob_alignment;
 
        /* protects uuid state when exporting */
        spinlock_t resource_export_lock;

diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 80ba69b4860bc58405de68b1379810b12a93428c..cfde9f573df6ecbcbb9d0e8cad777a987ebf477e 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -124,7 +124,7 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
        struct virtio_gpu_device *vgdev;
        /* this will expand later */
        struct virtqueue *vqs[2];
-       u32 num_scanouts, num_capsets;
+       u32 num_scanouts, num_capsets, blob_alignment;
        int ret = 0;
 
        if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
@@ -198,14 +198,22 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
        if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_CONTEXT_INIT))
                vgdev->has_context_init = true;
 
+       if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_BLOB_ALIGNMENT)) {
+               vgdev->has_blob_alignment = true;
+               virtio_cread_le(vgdev->vdev, struct virtio_gpu_config,
+                               blob_alignment, &blob_alignment);
+               vgdev->blob_alignment = blob_alignment;
+       }
+
        DRM_INFO("features: %cvirgl %cedid %cresource_blob %chost_visible",
                 vgdev->has_virgl_3d    ? '+' : '-',
                 vgdev->has_edid        ? '+' : '-',
                 vgdev->has_resource_blob ? '+' : '-',
                 vgdev->has_host_visible ? '+' : '-');
 
-       DRM_INFO("features: %ccontext_init\n",
-                vgdev->has_context_init ? '+' : '-');
+       DRM_INFO("features: %ccontext_init %cblob_alignment\n",
+                vgdev->has_context_init ? '+' : '-',
+                vgdev->has_blob_alignment ? '+' : '-');
 
        ret = virtio_find_vqs(vgdev->vdev, 2, vqs, vqs_info, NULL);
        if (ret) {

diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
index be109777d10db1251e3eb0bfbd314b4d43d0b5fc..4f530d90058c724519a69cf6caec45035a72b12d 100644 (file)
--- a/include/uapi/linux/virtio_gpu.h
+++ b/include/uapi/linux/virtio_gpu.h
@@ -64,6 +64,14 @@
  * context_init and multiple timelines
  */
 #define VIRTIO_GPU_F_CONTEXT_INIT        4
+/*
+ * The device provides a valid blob_alignment
+ * field in its configuration and both
+ * VIRTIO_GPU_CMD_RESOURCE_CREATE_BLOB and
+ * VIRTIO_GPU_CMD_RESOURCE_MAP_BLOB requests
+ * must be aligned to that value.
+ */
+#define VIRTIO_GPU_F_BLOB_ALIGNMENT      5
 
 enum virtio_gpu_ctrl_type {
        VIRTIO_GPU_UNDEFINED = 0,
@@ -365,6 +373,7 @@ struct virtio_gpu_config {
        __le32 events_clear;
        __le32 num_scanouts;
        __le32 num_capsets;
+       __le32 blob_alignment;
 };
 
 /* simple formats for fbcon/X use */