On Mon, Apr 8, 2024 at 5:28 AM Zack Rusin zack.rusin@broadcom.com wrote:

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+

---

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c index 41ad13e45554..bdad93864b98 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c @@ -667,11 +667,12 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv) [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;
  

-- 2.40.1

LGTM!

Reviewed-by: Martin Krastev martin.krastev@broadcom.com

Regards, Martin