Re: [PATCH 1/1] vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0]
From: Alexey Kardashevskiy <hidden>
Date: 2020-02-06 04:24:57
Also in:
kvm
On 06/02/2020 14:17, Sam Bobroff wrote:
quoted hunk ↗ jump to hunk
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. Signed-off-by: Sam Bobroff <redacted> --- drivers/vfio/pci/vfio_pci_nvlink2.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)diff --git a/drivers/vfio/pci/vfio_pci_nvlink2.c b/drivers/vfio/pci/vfio_pci_nvlink2.c index f2983f0f84be..851ba673882b 100644 --- a/drivers/vfio/pci/vfio_pci_nvlink2.c +++ b/drivers/vfio/pci/vfio_pci_nvlink2.c@@ -420,8 +420,17 @@ 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; + dev_warn(&vdev->pdev->dev, + "No ibm,mmio-atsd[%d] found: trying ibm,mmio-atsd[0]\n", + nvlink_index);
We do not really need this warning (nvlink_index doesn't matter that much, we can work out from the device tree what happened), warnings below are enough (if you really want, you can print nvlink_index there). Either way, Reviewed-by: Alexey Kardashevskiy <redacted>
+ 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)) {-- Alexey