This is a note to let you know that I've just added the patch titled
drm/amd/display: Enable HostVM based on rIOMMU active
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-enable-hostvm-based-on-riommu-active.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bbcfad4bfa4c67089488b934c8be1157f16ae520
Author: Gabe Teeger <gabe.teeger@xxxxxxx>
Date: Thu Feb 23 11:30:31 2023 -0500
drm/amd/display: Enable HostVM based on rIOMMU active
[ Upstream commit 97fa4dfa66fdd52ad3d0c9fadeaaa1e87605bac7 ]
[Why]
There is underflow and flickering occuring. The
underflow stops when hostvm is forced to active.
According to policy, hostvm should be enabled if riommu
is active, but this is not taken into account when
deciding whether to enable hostvm.
[What]
For DCN314, set hostvm to true if riommu is active.
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx>
Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
Signed-off-by: Gabe Teeger <gabe.teeger@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
index 3bbc46a673355..28163f7acd5b2 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
@@ -308,6 +308,10 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c
pipe->plane_state->src_rect.width < pipe->plane_state->dst_rect.width))
upscaled = true;
+ /* Apply HostVM policy - either based on hypervisor globally enabled, or rIOMMU active */
+ if (dc->debug.dml_hostvm_override == DML_HOSTVM_NO_OVERRIDE)
+ pipes[i].pipe.src.hostvm = dc->vm_pa_config.is_hvm_enabled || dc->res_pool->hubbub->riommu_active;
+
/*
* Immediate flip can be set dynamically after enabling the plane.
* We need to require support for immediate flip or underflow can be
