From 1f37280b37dbf85f36748f359a9f8802c8fe7ccd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Wed, 23 Oct 2024 09:50:56 +0100 Subject: [PATCH] net: fix build when libbpf is disabled, but libxdp is enabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The net/af-xdp.c code is enabled when the libxdp library is present, however, it also has direct API calls to bpf_xdp_query_id & bpf_xdp_detach which are provided by the libbpf library. As a result if building with --disable-libbpf, but libxdp gets auto-detected, we'll fail to link QEMU /usr/bin/ld: libcommon.a.p/net_af-xdp.c.o: undefined reference to symbol 'bpf_xdp_query_id@@LIBBPF_0.7.0' There are two bugs here * Since we have direct libbpf API calls, when building net/af-xdp.c, we must tell meson that libbpf is a dependancy, so that we directly link to it, rather than relying on indirect linkage. * When must skip probing for libxdp at all, when libbpf is not found, raising an error if --enable-libxdp was given explicitly. Fixes: cb039ef3d9e3112da01e1ecd9b136ac9809ef733 Signed-off-by: Daniel P. Berrangé Signed-off-by: Jason Wang --- meson.build | 10 ++++++++-- net/meson.build | 2 +- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/meson.build b/meson.build index c26c417de1..9432c5f173 100644 --- a/meson.build +++ b/meson.build @@ -2164,8 +2164,14 @@ endif # libxdp libxdp = not_found if not get_option('af_xdp').auto() or have_system - libxdp = dependency('libxdp', required: get_option('af_xdp'), - version: '>=1.4.0', method: 'pkg-config') + if libbpf.found() + libxdp = dependency('libxdp', required: get_option('af_xdp'), + version: '>=1.4.0', method: 'pkg-config') + else + if get_option('af_xdp').enabled() + error('libxdp requested, but libbpf is not available') + endif + endif endif # libdw diff --git a/net/meson.build b/net/meson.build index e0cd71470e..bb97b4dcbe 100644 --- a/net/meson.build +++ b/net/meson.build @@ -39,7 +39,7 @@ if have_netmap system_ss.add(files('netmap.c')) endif -system_ss.add(when: libxdp, if_true: files('af-xdp.c')) +system_ss.add(when: [libxdp, libbpf], if_true: files('af-xdp.c')) if have_vhost_net_user system_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('vhost-user.c'), if_false: files('vhost-user-stub.c'))