-----Original Message----- > Date: Wed, 31 Jan 2018 10:38:32 +0000 > From: Ophir Munk <[email protected]> > To: Jerin Jacob <[email protected]> > CC: "[email protected]" <[email protected]>, Thomas Monjalon <[email protected]>, > Pascal Mazon <[email protected]>, Jan Viktorin > <[email protected]>, Jianbo Liu <[email protected]> > Subject: RE: [dpdk-dev] [PATCH] net/tap: fix build issue with ARM32 > > Hi, > Please see inline > > > -----Original Message----- > > From: Jerin Jacob [mailto:[email protected]] > > Sent: Wednesday, January 31, 2018 12:24 PM > > To: Ophir Munk <[email protected]> > > Cc: [email protected]; Thomas Monjalon <[email protected]>; Pascal > > Mazon <[email protected]>; Jan Viktorin > > <[email protected]>; Jianbo Liu <[email protected]> > > Subject: Re: [dpdk-dev] [PATCH] net/tap: fix build issue with ARM32 > > > > -----Original Message----- > > > Date: Wed, 31 Jan 2018 09:59:45 +0000 > > > From: Ophir Munk <[email protected]> > > > To: Jerin Jacob <[email protected]>, "[email protected]" > > > <[email protected]> > > > CC: Thomas Monjalon <[email protected]>, Pascal Mazon > > > <[email protected]>, Jan Viktorin <[email protected]>, > > > Jianbo Liu <[email protected]> > > > Subject: RE: [dpdk-dev] [PATCH] net/tap: fix build issue with ARM32 > > > > > > Hi, > > > Please see comments inline > > > > > > > -----Original Message----- > > > > From: dev [mailto:[email protected]] On Behalf Of Jerin Jacob > > > > Sent: Wednesday, January 31, 2018 7:14 AM > > > > To: [email protected] > > > > Cc: Thomas Monjalon <[email protected]>; Jerin Jacob > > > > <[email protected]>; Pascal Mazon > > > > <[email protected]>; Jan Viktorin <[email protected]>; > > > > Jianbo Liu <[email protected]> > > > > Subject: [dpdk-dev] [PATCH] net/tap: fix build issue with ARM32 > > > > > > > > arm32 Linux does not support eBPF interface. > > > > Since tap PMD driver has a dependency on eBPF(the symbol __NR_bpf), > > > > disabling it armv7 config. > > > > > > > > compilation error log: > > > > In file included from /tmp/dpdk/drivers/net/tap/tap_bpf_api.c:15:0: > > > > /tmp/dpdk/drivers/net/tap/tap_bpf.h:103:4: error: #error __NR_bpf > > > > not defined # error __NR_bpf not defined > > > > ^ > > > > > > arm architecture is missing is file drivers/tap/tap_bpf.h I suggest > > > adding it, for example > > > > > > # elif defined(__arm__) > > > # define __NR_bpf 386 > > > > By looking at Linux source code > > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Felixi > > r.free- > > electrons.com%2Flinux%2Fv4.15%2Fsource%2Ftools%2Fbuild%2Ffeature%2 > > Ftest- > > bpf.c%23L6&data=02%7C01%7Cophirmu%40mellanox.com%7C19f50ad7f27 > > 34d00173808d56894c997%7Ca652971c7d2e4d9ba6a4d149256f461b%7C0% > > 7C0%7C636529910613736017&sdata=ynsxHG9fvao4LyfWLo4GVJjlKNmcF0q > > 0BkFocJyarAE%3D&reserved=0 > > I am not sure, Is eBPF support available for arm32 support? > > TAP eBPF has a graceful approach: it must successfully compile on all Linux > distributions. If a specific kernel cannot support eBPF it will gracefully > refuse the eBPF netlink message sent to it. > Thus, there is no harm even if there is no eBPF support available for arm32.
OK. But, To enable grace full refuse, we should not any random system call number like #define __NR_bpf 386. It should at least unused for arm32. > > You should enable TAP compilation for cases where you only need TAP without > eBPF. Yes. It would have been better if new eBPF depended features would have under conditional compilation flag so it it can be turned off selectively. > > > > > > > > > It should work for you. Can you please try it? > > > > I don't have access to an arm32 board. I was facing cross compilation build > > issue with arm32. > > > > > If it doesn't work for you, please have a look in this link: > > > > > > > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsou > > > > > rceforge.net%2Fp%2Fpredef%2Fwiki%2FArchitectures%2F&data=02%7C01% > > 7Coph > > > > > irmu%40mellanox.com%7C19f50ad7f2734d00173808d56894c997%7Ca6529 > > 71c7d2e4 > > > > > d9ba6a4d149256f461b%7C0%7C0%7C636529910613736017&sdata=g5fEkG > > Gwm%2BJgR > > > KyDrxJgbFII0%2B1%2BxtbT%2FE4Qy1HACEg%3D&reserved=0 > > > where you can see more arm architecture definitions. > > > You should find the one suitable for you. > > > > I guess, it is not just matter of enabling the build for arm32. It should > > work at > > runtime too, If some can confirm following addition in the > > drivers/net/tap/tap_bpf.h works then we can add it. > > > > As mentioned above it must not work at runtime too. > > > # elif defined(__arm__) > > # define __NR_bpf 386 > > > > > > > > > /tmp/dpdk/drivers/net/tap/tap_bpf_api.c: In function ‘sys_bpf’: > > > > /tmp/dpdk/drivers/net/tap/tap_bpf_api.c:92:17: error: ‘__NR_bpf’ > > > > undeclared (first use in this function) > > > > return syscall(__NR_bpf, cmd, attr, size); > > > > ^ > > > > /tmp/dpdk/drivers/net/tap/tap_bpf_api.c:92:17: note: each undeclared > > > > identifier is reported only once for each function it appears in > > > > /tmp/dpdk/drivers/net/tap/tap_bpf_api.c:93:1: error: control reaches > > > > end of non-void function [-Werror=return-type] } ^ > > > > cc1: all warnings being treated as errors > > > > > > > > Fixes: b02d85e1 ("net/tap: add eBPF API") > > > > > > > > Cc: Pascal Mazon <[email protected]> > > > > Cc: Jan Viktorin <[email protected]> > > > > Cc: Jianbo Liu <[email protected]> > > > > > > > > Signed-off-by: Jerin Jacob <[email protected]> > > > > --- > > > > config/defconfig_arm-armv7a-linuxapp-gcc | 1 + > > > > 1 file changed, 1 insertion(+) > > > > > > > > diff --git a/config/defconfig_arm-armv7a-linuxapp-gcc > > > > b/config/defconfig_arm-armv7a-linuxapp-gcc > > > > index a20b7a85f..4a55bb397 100644 > > > > --- a/config/defconfig_arm-armv7a-linuxapp-gcc > > > > +++ b/config/defconfig_arm-armv7a-linuxapp-gcc > > > > @@ -80,3 +80,4 @@ CONFIG_RTE_LIBRTE_BNX2X_PMD=n > > > > CONFIG_RTE_LIBRTE_QEDE_PMD=n > > CONFIG_RTE_LIBRTE_SFC_EFX_PMD=n > > > > CONFIG_RTE_LIBRTE_AVP_PMD=n > > > > +CONFIG_RTE_LIBRTE_PMD_TAP=n > > > > -- > > > > > > I suggest fixing the compilation issue by adding the missing > > > architecture system call number (as suggested above) instead of > > > disabling TAP compilation by default > > > > > > > 2.16.1 > > >
