Using the GPU with a VRAM Carveout is a security vulnerability. Nevertheless it is sometimes required, especially when no IOMMU implementation is available for a certain platform.
Signed-off-by: Iskren Chernev iskren.chernev@gmail.com --- drivers/gpu/drm/msm/adreno/a2xx_gpu.c | 6 ++++-- drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 6 ++++-- drivers/gpu/drm/msm/adreno/a4xx_gpu.c | 6 ++++-- drivers/gpu/drm/msm/adreno/adreno_device.c | 4 ++++ drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 + 5 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a2xx_gpu.c b/drivers/gpu/drm/msm/adreno/a2xx_gpu.c index 7e82c41a85f1a..bdc989183c648 100644 --- a/drivers/gpu/drm/msm/adreno/a2xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a2xx_gpu.c @@ -534,8 +534,10 @@ struct msm_gpu *a2xx_gpu_init(struct drm_device *dev)
if (!gpu->aspace) { dev_err(dev->dev, "No memory protection without MMU\n"); - ret = -ENXIO; - goto fail; + if (!allow_vram_carveout) { + ret = -ENXIO; + goto fail; + } }
return gpu; diff --git a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c index 93da6683a8661..4534633fe7cdb 100644 --- a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c @@ -564,8 +564,10 @@ struct msm_gpu *a3xx_gpu_init(struct drm_device *dev) * implement a cmdstream validator. */ DRM_DEV_ERROR(dev->dev, "No memory protection without IOMMU\n"); - ret = -ENXIO; - goto fail; + if (!allow_vram_carveout) { + ret = -ENXIO; + goto fail; + } }
icc_path = devm_of_icc_get(&pdev->dev, "gfx-mem"); diff --git a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c index c0be3a0f36b2c..82bebb40234de 100644 --- a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c @@ -692,8 +692,10 @@ struct msm_gpu *a4xx_gpu_init(struct drm_device *dev) * implement a cmdstream validator. */ DRM_DEV_ERROR(dev->dev, "No memory protection without IOMMU\n"); - ret = -ENXIO; - goto fail; + if (!allow_vram_carveout) { + ret = -ENXIO; + goto fail; + } }
icc_path = devm_of_icc_get(&pdev->dev, "gfx-mem"); diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index 87c8b033ad1a6..12e75ba360f95 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -18,6 +18,10 @@ bool snapshot_debugbus = false; MODULE_PARM_DESC(snapshot_debugbus, "Include debugbus sections in GPU devcoredump (if not fused off)"); module_param_named(snapshot_debugbus, snapshot_debugbus, bool, 0600);
+bool allow_vram_carveout = false; +MODULE_PARM_DESC(allow_vram_carveout, "Allow using VRAM Carveout, in place of IOMMU"); +module_param_named(allow_vram_carveout, allow_vram_carveout, bool, 0600); + static const struct adreno_info gpulist[] = { { .rev = ADRENO_REV(2, 0, 0, 0), diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h index c3775f79525a7..fe5444a1482ae 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h @@ -18,6 +18,7 @@ #include "adreno_pm4.xml.h"
extern bool snapshot_debugbus; +extern bool allow_vram_carveout;
enum { ADRENO_FW_PM4 = 0,