On Thu, 10 Nov 2022 12:42:43 -0500 Luc Pelletier <lucp.at.w...@gmail.com> wrote:
> When the failsafe PMD encounters a hotplug event, it switches its rx/tx > functions to "safe" ones that validate the sub-device's rx/tx functions > before calling them. It switches the rx/tx functions by changing the > function pointers in the rte_eth_dev structure. > > Following commit 7a0935239b9e, the rx/tx functions of PMDs are no longer > called through the function pointers in the rte_eth_dev structure. They > are rather called through a flat array named rte_eth_fp_ops. The > function pointers in that array are initialized when the devices start > and are initialized. > > When a hotplug event occurs, the function pointers in rte_eth_fp_ops > still point to the "unsafe" rx/tx functions in the failsafe PMD since > they haven't been updated. This results in a segmentation fault because > it ends up using the "unsafe" functions, when the "safe" functions > should have been used. > > To fix the problem, the failsafe PMD code was changed to update the > function pointers in the rte_eth_fp_ops array when a hotplug event > occurs. Have it in both places might be breaking other drivers as well. Shouldn't there be a ethdev function when changing rx/tx burst. Also, changing a variable used by another thread needs to be using __atomic_store and __atomic_load to guarantee that CPU or compiler will no that it changed.
