2019-08-22 12:31:58

by Gerd Hoffmann

Subject: [PATCH v2] drm/virtio: make resource id workaround runtime switchable.

Also update the comment with a reference to the virglrenderer fix.

Signed-off-by: Gerd Hoffmann <[email protected]>
---
drivers/gpu/drm/virtio/virtgpu_object.c | 44 ++++++++++++++-----------
1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index b2da31310d24..e98aaa00578d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -27,34 +27,38 @@

#include "virtgpu_drv.h"

+static int virtio_gpu_virglrenderer_workaround = 1;
+module_param_named(virglhack, virtio_gpu_virglrenderer_workaround, int, 0400);
+
static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
uint32_t *resid)
{
-#if 0
- int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL);
-
- if (handle < 0)
- return handle;
-#else
- static int handle;
-
- /*
- * FIXME: dirty hack to avoid re-using IDs, virglrenderer
- * can't deal with that. Needs fixing in virglrenderer, also
- * should figure a better way to handle that in the guest.
- */
- handle++;
-#endif
-
- *resid = handle + 1;
+ if (virtio_gpu_virglrenderer_workaround) {
+ /*
+ * Hack to avoid re-using resource IDs.
+ *
+ * virglrenderer versions up to (and including) 0.7.0
+ * can't deal with that. virglrenderer commit
+ * "f91a9dd35715 Fix unlinking resources from hash
+ * table." (Feb 2019) fixes the bug.
+ */
+ static int handle;
+ handle++;
+ *resid = handle + 1;
+ } else {
+ int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL);
+ if (handle < 0)
+ return handle;
+ *resid = handle + 1;
+ }
return 0;
}

static void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id)
{
-#if 0
- ida_free(&vgdev->resource_ida, id - 1);
-#endif
+ if (!virtio_gpu_virglrenderer_workaround) {
+ ida_free(&vgdev->resource_ida, id - 1);
+ }
}

static void virtio_gpu_ttm_bo_destroy(struct ttm_buffer_object *tbo)
--
2.18.1

2019-08-26 22:07:56

by Chia-I Wu

Subject: Re: [PATCH v2] drm/virtio: make resource id workaround runtime switchable.

On Thu, Aug 22, 2019 at 3:26 AM Gerd Hoffmann <[email protected]> wrote:
>
> Also update the comment with a reference to the virglrenderer fix.
>
> Signed-off-by: Gerd Hoffmann <[email protected]>
Reviewed-by: Chia-I Wu <[email protected]>
> ---
> drivers/gpu/drm/virtio/virtgpu_object.c | 44 ++++++++++++++-----------
> 1 file changed, 24 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
> index b2da31310d24..e98aaa00578d 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_object.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_object.c
> @@ -27,34 +27,38 @@
>
> #include "virtgpu_drv.h"
>
> +static int virtio_gpu_virglrenderer_workaround = 1;
> +module_param_named(virglhack, virtio_gpu_virglrenderer_workaround, int, 0400);
> +
> static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
> uint32_t *resid)
> {
> -#if 0
> - int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL);
> -
> - if (handle < 0)
> - return handle;
> -#else
> - static int handle;
> -
> - /*
> - * FIXME: dirty hack to avoid re-using IDs, virglrenderer
> - * can't deal with that. Needs fixing in virglrenderer, also
> - * should figure a better way to handle that in the guest.
> - */
> - handle++;
> -#endif
> -
> - *resid = handle + 1;
> + if (virtio_gpu_virglrenderer_workaround) {
> + /*
> + * Hack to avoid re-using resource IDs.
> + *
> + * virglrenderer versions up to (and including) 0.7.0
> + * can't deal with that. virglrenderer commit
> + * "f91a9dd35715 Fix unlinking resources from hash
> + * table." (Feb 2019) fixes the bug.
> + */
> + static int handle;
> + handle++;
> + *resid = handle + 1;
> + } else {
> + int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL);
> + if (handle < 0)
> + return handle;
> + *resid = handle + 1;
> + }
> return 0;
> }
>
> static void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id)
> {
> -#if 0
> - ida_free(&vgdev->resource_ida, id - 1);
> -#endif
> + if (!virtio_gpu_virglrenderer_workaround) {
> + ida_free(&vgdev->resource_ida, id - 1);
> + }
> }
>
> static void virtio_gpu_ttm_bo_destroy(struct ttm_buffer_object *tbo)
> --
> 2.18.1
>
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