Re: [PATCH v2 1/1] vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0]
From: Alex Williamson <hidden>
Date: 2020-04-01 22:41:52
Also in:
kvm
On Tue, 31 Mar 2020 15:12:46 +1100 Sam Bobroff [off-list ref] wrote:
Older versions of skiboot only provide a single value in the device
tree property "ibm,mmio-atsd", even when multiple Address Translation
Shoot Down (ATSD) registers are present. This prevents NVLink2 devices
(other than the first) from being used with vfio-pci because vfio-pci
expects to be able to assign a dedicated ATSD register to each NVLink2
device.
However, ATSD registers can be shared among devices. This change
allows vfio-pci to fall back to sharing the register at index 0 if
necessary.
Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Signed-off-by: Sam Bobroff <redacted>
---
Patch set v2:
Patch 1/1: vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0]
- Removed unnecessary warning.
- Added Fixes tag.
Patch set v1:
Patch 1/1: vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0]
drivers/vfio/pci/vfio_pci_nvlink2.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)Applied to vfio next branch for v5.7 with Alexey's review. Thanks, Alex
quoted hunk ↗ jump to hunk
diff --git a/drivers/vfio/pci/vfio_pci_nvlink2.c b/drivers/vfio/pci/vfio_pci_nvlink2.c index f2983f0f84be..ae2af590e501 100644 --- a/drivers/vfio/pci/vfio_pci_nvlink2.c +++ b/drivers/vfio/pci/vfio_pci_nvlink2.c@@ -420,8 +420,14 @@ int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev) if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", nvlink_index, &mmio_atsd)) { - dev_warn(&vdev->pdev->dev, "No available ATSD found\n"); - mmio_atsd = 0; + if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", 0, + &mmio_atsd)) { + dev_warn(&vdev->pdev->dev, "No available ATSD found\n"); + mmio_atsd = 0; + } else { + dev_warn(&vdev->pdev->dev, + "Using fallback ibm,mmio-atsd[0] for ATSD.\n"); + } } if (of_property_read_u64(npu_node, "ibm,device-tgt-addr", &tgt)) {