Re: [PATCH net] hv_netvsc: Fix XDP refcnt for synthetic and VF NICs

[David Miller]

From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Date: Thu,  6 Feb 2020 14:01:05 -0800

> The caller of XDP_SETUP_PROG has already incremented refcnt in
> __bpf_prog_get(), so drivers should only increment refcnt by
> num_queues - 1.
> 
> To fix the issue, update netvsc_xdp_set() to add the correct number
> to refcnt.
> 
> Hold a refcnt in netvsc_xdp_set()ʼs other caller, netvsc_attach().
> 
> And, do the same in netvsc_vf_setxdp(). Otherwise, every time when VF is
> removed and added from the host side, the refcnt will be decreased by one,
> which may cause page fault when unloading xdp program.
> 
> Fixes: 351e1581395f ("hv_netvsc: Add XDP support")
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>

Applied, thank you.