From: Alexey Kardashevskiy aik@ozlabs.ru
commit d22f9a6c92de96304c81792942ae7c306f08ac77 upstream.
We execute certain NPU2 setup code (such as mapping an LPID to a device in NPU2) unconditionally if an Nvlink bridge is detected. However this cannot succeed on POWER8NVL machines as the init helpers return an error other than ENODEV which means the device is there is and setup failed so vfio_pci_enable() fails and pass through is not possible.
This changes the two NPU2 related init helpers to return -ENODEV if there is no "memory-region" device tree property as this is the distinction between NPU and NPU2.
Tested on - POWER9 pvr=004e1201, Ubuntu 19.04 host, Ubuntu 18.04 vm, NVIDIA GV100 10de:1db1 driver 418.39 - POWER8 pvr=004c0100, RHEL 7.6 host, Ubuntu 16.10 vm, NVIDIA P100 10de:15f9 driver 396.47
Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Cc: stable@vger.kernel.org # 5.0 Signed-off-by: Alexey Kardashevskiy aik@ozlabs.ru Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/vfio/pci/vfio_pci_nvlink2.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/vfio/pci/vfio_pci_nvlink2.c +++ b/drivers/vfio/pci/vfio_pci_nvlink2.c @@ -231,7 +231,7 @@ int vfio_pci_nvdia_v100_nvlink2_init(str return -EINVAL;
if (of_property_read_u32(npu_node, "memory-region", &mem_phandle)) - return -EINVAL; + return -ENODEV;
mem_node = of_find_node_by_phandle(mem_phandle); if (!mem_node) @@ -393,7 +393,7 @@ int vfio_pci_ibm_npu2_init(struct vfio_p int ret; struct vfio_pci_npu2_data *data; struct device_node *nvlink_dn; - u32 nvlink_index = 0; + u32 nvlink_index = 0, mem_phandle = 0; struct pci_dev *npdev = vdev->pdev; struct device_node *npu_node = pci_device_to_OF_node(npdev); struct pci_controller *hose = pci_bus_to_host(npdev->bus); @@ -408,6 +408,9 @@ int vfio_pci_ibm_npu2_init(struct vfio_p if (!pnv_pci_get_gpu_dev(vdev->pdev)) return -ENODEV;
+ if (of_property_read_u32(npu_node, "memory-region", &mem_phandle)) + return -ENODEV; + /* * NPU2 normally has 8 ATSD registers (for concurrency) and 6 links * so we can allocate one register per link, using nvlink index as