6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zack Rusin <zack.rusin@xxxxxxxxxxxx> commit 4c08f01934ab67d1d283d5cbaa52b923abcfe4cd upstream. Enable DMA mappings in vmwgfx after TTM has been fixed in commit 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem") This enables full guest-backed memory support and in particular allows usage of screen targets as the presentation mechanism. Signed-off-by: Zack Rusin <zack.rusin@xxxxxxxxxxxx> Reported-by: Ye Li <ye.li@xxxxxxxxxxxx> Tested-by: Ye Li <ye.li@xxxxxxxxxxxx> Fixes: 3b0d6458c705 ("drm/vmwgfx: Refuse DMA operation when SEV encryption is active") Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@xxxxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> # v6.6+ Reviewed-by: Martin Krastev <martin.krastev@xxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240408022802.358641-1-zack.rusin@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c @@ -666,11 +666,12 @@ static int vmw_dma_select_mode(struct vm [vmw_dma_map_populate] = "Caching DMA mappings.", [vmw_dma_map_bind] = "Giving up DMA mappings early."}; - /* TTM currently doesn't fully support SEV encryption. */ - if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) - return -EINVAL; - - if (vmw_force_coherent) + /* + * When running with SEV we always want dma mappings, because + * otherwise ttm tt pool pages will bounce through swiotlb running + * out of available space. + */ + if (vmw_force_coherent || cc_platform_has(CC_ATTR_MEM_ENCRYPT)) dev_priv->map_mode = vmw_dma_alloc_coherent; else if (vmw_restrict_iommu) dev_priv->map_mode = vmw_dma_map_bind;