From: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com
commit 19965d8259fdabc6806da92adda49684f5bcbec5 upstream.
While technically Xen dom0 is a virtual machine too, it does have access to most of the hardware so it doesn't need to be considered a "passthrough". Commit b818a5d37454 ("drm/amdgpu/gmc: use PCI BARs for APUs in passthrough") changed how FB is accessed based on passthrough mode. This breaks amdgpu in Xen dom0 with message like this:
[drm:dc_dmub_srv_wait_idle [amdgpu]] *ERROR* Error waiting for DMUB idle: status=3
While the reason for this failure is unclear, the passthrough mode is not really necessary in Xen dom0 anyway. So, to unbreak booting affected kernels, disable passthrough mode in this case.
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1985 Fixes: b818a5d37454 ("drm/amdgpu/gmc: use PCI BARs for APUs in passthrough") Signed-off-by: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c @@ -24,6 +24,7 @@ #include <linux/module.h>
#include <drm/drm_drv.h> +#include <xen/xen.h>
#include "amdgpu.h" #include "amdgpu_ras.h" @@ -708,7 +709,8 @@ void amdgpu_detect_virtualization(struct adev->virt.caps |= AMDGPU_SRIOV_CAPS_ENABLE_IOV;
if (!reg) { - if (is_virtual_machine()) /* passthrough mode exclus sriov mod */ + /* passthrough mode exclus sriov mod */ + if (is_virtual_machine() && !xen_initial_domain()) adev->virt.caps |= AMDGPU_PASSTHROUGH_MODE; }