6.6-stable review patch. If anyone has any objections, please let me know.
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From: Zack Rusin zack.rusin@broadcom.com
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@broadcom.com Reported-by: Ye Li ye.li@broadcom.com Tested-by: Ye Li ye.li@broadcom.com Fixes: 3b0d6458c705 ("drm/vmwgfx: Refuse DMA operation when SEV encryption is active") Cc: Broadcom internal kernel review list bcm-kernel-feedback-list@broadcom.com Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v6.6+ Reviewed-by: Martin Krastev martin.krastev@broadcom.com Link: https://patchwork.freedesktop.org/patch/msgid/20240408022802.358641-1-zack.r... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;