patch 'net/af_xdp: make compatible with libbpf 0.8.0' has been queued to stable release 21.11.6

[Kevin Traynor]

On 11/12/2023 12:44, Loftus, Ciara wrote:
>>
>> Hi Ciara,
>>
>> On 07/12/2023 11:21, Kevin Traynor wrote:
>>> Hi,
>>>
>>> FYI, your patch has been queued to stable release 21.11.6
>>>
>>> Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
>>> It will be pushed if I get no objections before 12/12/23. So please
>>> shout if anyone has objections.
>>>
>>> Also note that after the patch there's a diff of the upstream commit vs the
>>> patch applied to the branch. This will indicate if there was any rebasing
>>> needed to apply to the stable branch. If there were code changes for
>> rebasing
>>> (ie: not only metadata diffs), please double check that the rebase was
>>> correctly done.
>>>
>>> Queued patches are on a temporary branch at:
>>> https://github.com/kevintraynor/dpdk-stable
>>>
>>> This queued commit can be viewed at:
>>> https://github.com/kevintraynor/dpdk-
>> stable/commit/770e7c27240d09571a62627c3bc90b8e6e9f6024
>>>
>>> Thanks.
>>>
>>> Kevin
>>>
>>> ---
>>>   From 770e7c27240d09571a62627c3bc90b8e6e9f6024 Mon Sep 17
>> 00:00:00 2001
>>> From: Ciara Loftus <ciara.loftus at intel.com>
>>> Date: Thu, 6 Oct 2022 09:26:54 +0300
>>> Subject: [PATCH] net/af_xdp: make compatible with libbpf 0.8.0
>>>
>>> [ upstream commit 1eb1846b1a2caaf77d0697747d3ecd1272ce0bfc ]
>>>
>>> libbpf v0.8.0 deprecates the bpf_get_link_xdp_id() and
>>> bpf_set_link_xdp_fd() functions. Use meson to detect if
>>> bpf_xdp_attach() is available and if so, use the recommended
>>> replacement functions bpf_xdp_query_id(), bpf_xdp_attach()
>>> and bpf_xdp_detach().
>>>
>>> Signed-off-by: Ciara Loftus <ciara.loftus at intel.com>
>>> Signed-off-by: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
>>> Reviewed-by: Ferruh Yigit <ferruh.yigit at xilinx.com>
>>> ---
>>>    drivers/net/af_xdp/meson.build      |  8 ++++++
>>>    drivers/net/af_xdp/rte_eth_af_xdp.c | 38
>> ++++++++++++++++++++++++++++-
>>>    2 files changed, 45 insertions(+), 1 deletion(-)
>>>
>>
>> I saw that af_xdp driver was not building [0] on F38 with the libbpf and
>> libxdp packages [1]. Previously I had squashed the deprecation warnings
>> but now with newer package versions it seems that is not enough.
>>
>> The meson.build file has changed a bit from 21.11 to DPDK main, so I
>> tried to take the correct part from the above commit and it builds for
>> F38 now.
>>
>> I'm not sure if I missed some case, or there's some other commits that I
>> should backport.
>>
>> Can you have a look and if it's not right, send a patch or tell me which
>> patches should be backported ? (you can see the diff and full file on
>> the github link above).
> 
> Hi Kevin,
> 
> This patch was the final patch in a set of 6 from Andrew Rybchenko:
> https://patches.dpdk.org/project/dpdk/cover/20221006062654.1420349-1-andrew.rybchenko@oktetlabs.ru/
> 
> On its own the patch is enough to support libbpf 0.8.0 and no other changes are necessary. The rebase looks good to me.
> The rest of the patchset tidies up the meson file and removes version-based checks in favour of checking for the presence of functions in the library. It's not an essential change to backport IMO.
> 

ok, thanks for confirming Ciara, we can go with just that patch as it 
resolves the build issue.

thanks,
Kevin.

> Thanks,
> Ciara
> 
>>
>> thanks,
>> Kevin.
>>
>>
>> [0]
>> [1126/3148] Compiling C object
>> drivers/libtmp_rte_net_af_xdp.a.p/net_af_xdp_rte_eth_af_xdp.c.o
>> ../drivers/net/af_xdp/rte_eth_af_xdp.c: In function ‘remove_xdp_program’:
>> ../drivers/net/af_xdp/rte_eth_af_xdp.c:869:13: warning: implicit
>> declaration of function ‘bpf_get_link_xdp_id’
>> [-Wimplicit-function-declaration]
>>     869 |         if (bpf_get_link_xdp_id(internals->if_index, &curr_prog_id,
>>         |             ^~~~~~~~~~~~~~~~~~~
>> ../drivers/net/af_xdp/rte_eth_af_xdp.c:869:13: warning: nested extern
>> declaration of ‘bpf_get_link_xdp_id’ [-Wnested-externs]
>> ../drivers/net/af_xdp/rte_eth_af_xdp.c:874:9: warning: implicit
>> declaration of function ‘bpf_set_link_xdp_fd’; did you mean
>> ‘bpf_link__fd’? [-Wimplicit-function-declaration]
>>     874 |         bpf_set_link_xdp_fd(internals->if_index, -1,
>>         |         ^~~~~~~~~~~~~~~~~~~
>>         |         bpf_link__fd
>> ../drivers/net/af_xdp/rte_eth_af_xdp.c:874:9: warning: nested extern
>> declaration of ‘bpf_set_link_xdp_fd’ [-Wnested-externs]
>>
>>
>> [1]
>> $ rpm -qa | grep -e libbpf -e libxdp
>> libbpf-1.1.0-2.fc38.x86_64
>> libbpf-devel-1.1.0-2.fc38.x86_64
>> libxdp-1.4.1-1.fc38.x86_64
>> libxdp-devel-1.4.1-1.fc38.x86_64
>>
>>
>>
>>
>>> diff --git a/drivers/net/af_xdp/meson.build
>> b/drivers/net/af_xdp/meson.build
>>> index 1e0de23705..2605086d0c 100644
>>> --- a/drivers/net/af_xdp/meson.build
>>> +++ b/drivers/net/af_xdp/meson.build
>>> @@ -56,2 +56,10 @@ else
>>>        reason = 'missing header, "linux/if_xdp.h"'
>>>    endif
>>> +
>>> +if build
>>> +  if cc.has_function('bpf_xdp_attach',
>>> +                     prefix : '#include <bpf/libbpf.h>',
>>> +                     dependencies : bpf_dep)
>>> +      cflags += ['-DRTE_NET_AF_XDP_LIBBPF_XDP_ATTACH']
>>> +  endif
>>> +endif
>>> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
>> b/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> index 9918d3c5fd..6bc7178fc5 100644
>>> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> @@ -859,7 +859,41 @@ eth_stats_reset(struct rte_eth_dev *dev)
>>>    }
>>>
>>> +#ifdef RTE_NET_AF_XDP_LIBBPF_XDP_ATTACH
>>> +
>>> +static int link_xdp_prog_with_dev(int ifindex, int fd, __u32 flags)
>>> +{
>>> +	return bpf_xdp_attach(ifindex, fd, flags, NULL);
>>> +}
>>> +
>>> +static int
>>> +remove_xdp_program(struct pmd_internals *internals)
>>> +{
>>> +	uint32_t curr_prog_id = 0;
>>> +	int ret;
>>> +
>>> +	ret = bpf_xdp_query_id(internals->if_index,
>> XDP_FLAGS_UPDATE_IF_NOEXIST,
>>> +			       &curr_prog_id);
>>> +	if (ret != 0) {
>>> +		AF_XDP_LOG(ERR, "bpf_xdp_query_id failed\n");
>>> +		return ret;
>>> +	}
>>> +
>>> +	ret = bpf_xdp_detach(internals->if_index,
>> XDP_FLAGS_UPDATE_IF_NOEXIST,
>>> +			     NULL);
>>> +	if (ret != 0)
>>> +		AF_XDP_LOG(ERR, "bpf_xdp_detach failed\n");
>>> +	return ret;
>>> +}
>>> +
>>> +#else
>>> +
>>>    #pragma GCC diagnostic push
>>>    #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
>>>
>>> +static int link_xdp_prog_with_dev(int ifindex, int fd, __u32 flags)
>>> +{
>>> +	return bpf_set_link_xdp_fd(ifindex, fd, flags);
>>> +}
>>> +
>>>    static void
>>>    remove_xdp_program(struct pmd_internals *internals)
>>> @@ -878,4 +912,6 @@ remove_xdp_program(struct pmd_internals
>> *internals)
>>>    #pragma GCC diagnostic pop
>>>
>>> +#endif
>>> +
>>>    static void
>>>    xdp_umem_destroy(struct xsk_umem_info *umem)
>>> @@ -1190,5 +1226,5 @@ load_custom_xdp_prog(const char *prog_path,
>> int if_index, struct bpf_map **map)
>>>
>>>    	/* Link the program with the given network device */
>>> -	ret = bpf_set_link_xdp_fd(if_index, prog_fd,
>>> +	ret = link_xdp_prog_with_dev(if_index, prog_fd,
>>>    					XDP_FLAGS_UPDATE_IF_NOEXIST);
>>>    	if (ret) {
>