4678adf94d
Andrew and Nikolay reported connectivity issues with Cilium's service
load-balancing in case of vmxnet3.
If a BPF program for native XDP adds an encapsulation header such as
IPIP and transmits the packet out the same interface, then in case
of vmxnet3 a corrupted packet is being sent and subsequently dropped
on the path.
vmxnet3_xdp_xmit_frame() which is called e.g. via vmxnet3_run_xdp()
through vmxnet3_xdp_xmit_back() calculates an incorrect DMA address:
page = virt_to_page(xdpf->data);
tbi->dma_addr = page_pool_get_dma_addr(page) +
VMXNET3_XDP_HEADROOM;
dma_sync_single_for_device(&adapter->pdev->dev,
tbi->dma_addr, buf_size,
DMA_TO_DEVICE);
The above assumes a fixed offset (VMXNET3_XDP_HEADROOM), but the XDP
BPF program could have moved xdp->data. While the passed buf_size is
correct (xdpf->len), the dma_addr needs to have a dynamic offset which
can be calculated as xdpf->data - (void *)xdpf, that is, xdp->data -
xdp->data_hard_start.
Fixes:
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||
|---|---|---|
| .. | ||
| Makefile | ||
| upt1_defs.h | ||
| vmxnet3_defs.h | ||
| vmxnet3_drv.c | ||
| vmxnet3_ethtool.c | ||
| vmxnet3_int.h | ||
| vmxnet3_xdp.c | ||
| vmxnet3_xdp.h | ||