Known Issues

1.0

The following are known limitations of this NVMe/virtio-blk SNAP software version.

Ref #

Issue

Description: NVMeTCP XLIO is currently not supported when running 64K page size kernels on the DPU Arm cores (as is the case for CentOS 8.x, Rocky 8.x, or openEuler 20.x).

Workaround: N/A

Keywords: 64K page size; NVMeTCP XLIO

Discovered in version: 4.1.0

3264154

Description: NVMeTCP XLIO is not supported when running 64K page size kernels on the DPU Arm cores (such is the case with CentOS 8.x, Rocky 8.x, or openEuler 20.x).

Workaround: N/A

Keywords: Page size; NVMeTCP XLIO

Discovered in version: 4.1.0

Description: NVMe over RDMA full offload is not supported.

Workaround: N/A

Keywords: NVMe over RDMA; support

Discovered in version: 4.0.0

Description: SNAP is not supported on a host with Windows OS.

Workaround: N/A

Keywords: Windows; OS; support

Discovered in version: 4.0.0

Note

The following are not BlueField SNAP limitations.

Ref #

Issue

-

Description: If PCIe devices are inserted prior to the hot-plug driver being loaded on host, the hot-plug driver in kernel version less than 4.19 does not enable the slot even if the slot is occupied (i.e., presence detected in slot status register). That is, only the presence state of the slot is changed by firmware but the PCIe slot is not enabled by the kernel after host bootup (i.e.,

So that we can't get the PCIe device by lspci on host side, and the bdf is 0 on controller.

Workaround: Add pciehp.pciehp_force=1 to the boot command line on host.

Keywords: Virtio-blk; kernel driver; hot-plug

Reported in version: 4.2.1

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Description: RedHat/Centos 7.x does not handle "online" (post driver probe) namespace additions/removals correctly.

Workaround: Use --quirks=0x2 option in snap_rpc.py nvme_controller_create.

Keywords: NVMe; CentOS; RedHat; kernel

Reported in version: 4.1.0

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Description: Some Windows drivers have experimental support for "online" (post driver probe) namespace additions/removal, although such support is not communicated with the device.

Workaround: Use --quirks=0x1 option in snap_rpc.py nvme_controller_create.

Keywords: NVMe; Windows

Reported in version: 4.1.0

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Description: VMWare ESXi supports "online" (post driver probe) namespace additions/removal, only if “Namespace Management” is supported by controller.

Workaround: Use --quirks=0x8 option in snap_rpc.py nvme_controller_create.

Keywords: NVMe, ESXi

Reported in version: 4.1.0

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Description: Ubuntu 22.04 does not support 500 VFs.

Workaround: N/A

Keywords: Virtio-blk; kernel driver; Ubuntu 22.04

Reported in version: 4.1.0

Description: Virtio-blk Linux kernel driver does not handle PCIe FLR events.

Workaround: N/A

Keywords: Virtio-blk; kernel driver

Reported in version: 4.0.0

Description: A n ew virtio-blk Linux kernel driver (starting kernel 4.18) does not support hot-unplug during traffic. Since the kernel may self-generate spontaneous IOs, on rare occasions, an issue may happen even when no traffic is explicitly being run.

Workaround: N/A

Keywords: Virtio-blk; kernel driver

Reported in version: 4.0.0

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