RE: [EXTERNAL] Re: [PATCH 0/8] fix multi-process VF hotplug

Long Li
2026-02-21T02:47:14Z

> On Thu, 19 Feb 2026 17:08:51 -0800
> longli@linux.microsoft.com wrote:
>
> > From: Long Li <longli@microsoft.com>
> >
> > This series fixes multi-process support for DPDK drivers used on Azure
> > VMs with Accelerated Networking (AN). When AN is toggled, the VF
> > device is hot-removed and hot-added, which can crash secondary
> > processes due to stale fast-path pointers and race conditions.
> >
> > Patches 1-3 fix the netvsc PMD:
> > - Prevent secondary from calling unsupported promiscuous ops
> > - Fix rwlock misuse and race conditions on VF add/remove events
> > - Add multi-process VF device removal support via IPC
> >
> > Patches 4-5 fix resource leaks:
> > - MANA PD resource leak on device close
> > - netvsc devargs memory leak on hotplug
> >
> > Patches 6-8 fix a common bug across MANA, MLX5, and MLX4 drivers where
> > the secondary process START_RXTX/STOP_RXTX IPC handlers update
> > dev->rx_pkt_burst/tx_pkt_burst but do not update the process-local
> > rte_eth_fp_ops[] array. Since rte_eth_rx_burst() uses rte_eth_fp_ops
> > (not dev->rx_pkt_burst), the secondary retains stale queue data
> > pointers after VF hot-add, causing a segfault.
> >
> > Long Li (8):
> > net/netvsc: secondary ignore promiscuous enable/disable
> > net/netvsc: fix race conditions on VF add/remove events
> > net/netvsc: add multi-process VF device removal support
> > net/mana: fix PD resource leak on device close
> > net/netvsc: fix devargs memory leak on hotplug
> > net/mana: fix fast-path ops setup in secondary process
> > net/mlx5: fix fast-path ops setup in secondary process
> > net/mlx4: fix fast-path ops setup in secondary process
> >
> > drivers/net/mana/mana.c | 14 ++
> > drivers/net/mana/mp.c | 6 +
> > drivers/net/mlx4/mlx4_mp.c | 4 +
> > drivers/net/mlx5/linux/mlx5_mp_os.c | 4 +
> > drivers/net/netvsc/hn_ethdev.c | 288 +++++++++++++++++++++++++++-
> > drivers/net/netvsc/hn_nvs.h | 5 +
> > drivers/net/netvsc/hn_rxtx.c | 40 ++--
> > drivers/net/netvsc/hn_var.h | 1 +
> > drivers/net/netvsc/hn_vf.c | 122 ++++++------
> > 9 files changed, 397 insertions(+), 87 deletions(-)
> >
>
> I didn't see anything wrong, but AI review spotted some issues.
> Address these and resubmit.

Thank you, I have sent v2.

>
> Prompt: Using AGENTS.md, do a deep dive patch review of this patchset to DPDK
> VF support in Azure
>