2020-12-30 15:32:17

by Iskren Chernev

Subject: [PATCH 1/2] drm/msm: Call msm_init_vram before binding the gpu

From: Craig Tatlor <[email protected]>

vram.size is needed when binding a gpu without an iommu and is defined
in msm_init_vram(), so run that before binding it.

Signed-off-by: Craig Tatlor <[email protected]>
---
drivers/gpu/drm/msm/msm_drv.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 535a0263ceeb4..108c405e03dd9 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -457,14 +457,14 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)

drm_mode_config_init(ddev);

- /* Bind all our sub-components: */
- ret = component_bind_all(dev, ddev);
+ ret = msm_init_vram(ddev);
if (ret)
goto err_destroy_mdss;

- ret = msm_init_vram(ddev);
+ /* Bind all our sub-components: */
+ ret = component_bind_all(dev, ddev);
if (ret)
- goto err_msm_uninit;
+ goto err_destroy_mdss;

dma_set_max_seg_size(dev, UINT_MAX);


base-commit: d7a03a44a5e93f39ece70ec75d25c6088caa0fdb
prerequisite-patch-id: aba6f684932cab35d98457c21e4ff7a5ac75c753
prerequisite-patch-id: 4884d57df1bd197896b69e115d9002d6c26ae2e2
--
2.29.2

2020-12-30 15:33:18

by Iskren Chernev

Subject: [PATCH 2/2] drm/msm: Add modparam to allow vram carveout

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 <[email protected]>
---
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,
--
2.29.2

2020-12-30 22:35:38

by Brian Masney

Subject: Re: [PATCH 1/2] drm/msm: Call msm_init_vram before binding the gpu

On Wed, Dec 30, 2020 at 05:29:42PM +0200, Iskren Chernev wrote:
> From: Craig Tatlor <[email protected]>
>
> vram.size is needed when binding a gpu without an iommu and is defined
> in msm_init_vram(), so run that before binding it.
>
> Signed-off-by: Craig Tatlor <[email protected]>

For the series:

Reviewed-by: Brian Masney <[email protected]>

Next time, please include a cover letter so that tags added to the cover
letter can be applied to all patches in the series via patchwork.

Brian

2021-01-03 06:11:49

by Alexey Minnekhanov

Subject: Re: [PATCH 1/2] drm/msm: Call msm_init_vram before binding the gpu

Tested these patches on Samsung Galaxy S5 along with other patches that
add panel driver and enable GPU support on this device.

Tested-by: Alexey Minnekhanov <[email protected]>

On 12/30/20 6:29 PM, Iskren Chernev wrote:
> From: Craig Tatlor <[email protected]>
>
> vram.size is needed when binding a gpu without an iommu and is defined
> in msm_init_vram(), so run that before binding it.
>
> Signed-off-by: Craig Tatlor <[email protected]>
> ---
> drivers/gpu/drm/msm/msm_drv.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>