[PATCH] drm/amdgpu/gmc: use PCI BARs for APUs in passthrough

Alex Deucher alexander.deucher at amd.com
Thu Mar 10 18:06:15 UTC 2022


If the GPU is passed through to a guest VM, use the PCI
BAR for CPU FB access rather than the physical address of
carve out.  The physical address is not valid in a guest.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c | 2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c  | 5 +++--
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c  | 2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c  | 2 +-
 4 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
index f60b7bd4dbf5..9887a60e8eae 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
@@ -814,7 +814,7 @@ static int gmc_v10_0_mc_init(struct amdgpu_device *adev)
 	adev->gmc.aper_size = pci_resource_len(adev->pdev, 0);
 
 #ifdef CONFIG_X86_64
-	if (adev->flags & AMD_IS_APU) {
+	if ((adev->flags & AMD_IS_APU) && !amdgpu_passthrough(adev)) {
 		adev->gmc.aper_base = adev->gfxhub.funcs->get_mc_fb_offset(adev);
 		adev->gmc.aper_size = adev->gmc.real_vram_size;
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index 344d819b4c1b..979da6f510e8 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -381,8 +381,9 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev)
 	adev->gmc.aper_size = pci_resource_len(adev->pdev, 0);
 
 #ifdef CONFIG_X86_64
-	if (adev->flags & AMD_IS_APU &&
-	    adev->gmc.real_vram_size > adev->gmc.aper_size) {
+	if ((adev->flags & AMD_IS_APU) &&
+	    adev->gmc.real_vram_size > adev->gmc.aper_size &&
+	    !amdgpu_passthrough(adev)) {
 		adev->gmc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) << 22;
 		adev->gmc.aper_size = adev->gmc.real_vram_size;
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index ca9841d5669f..1932a3e4af7e 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -581,7 +581,7 @@ static int gmc_v8_0_mc_init(struct amdgpu_device *adev)
 	adev->gmc.aper_size = pci_resource_len(adev->pdev, 0);
 
 #ifdef CONFIG_X86_64
-	if (adev->flags & AMD_IS_APU) {
+	if ((adev->flags & AMD_IS_APU) && !amdgpu_passthrough(adev)) {
 		adev->gmc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) << 22;
 		adev->gmc.aper_size = adev->gmc.real_vram_size;
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index 431742eb7811..5fa613d41799 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -1456,7 +1456,7 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 	 */
 
 	/* check whether both host-gpu and gpu-gpu xgmi links exist */
-	if ((adev->flags & AMD_IS_APU) ||
+	if (((adev->flags & AMD_IS_APU) && !amdgpu_passthrough(adev)) ||
 	    (adev->gmc.xgmi.supported &&
 	     adev->gmc.xgmi.connected_to_cpu)) {
 		adev->gmc.aper_base =
-- 
2.35.1



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