Subject: RE: [PATCH bpf-next 3/4] selftests/bpf: restructure xsk selftests

From: "Loftus, Ciara" <[email-masked]>
Date: Tue, 23 Feb 2021 08:24:25 +0000

> 
> On Wed, Feb 17, 2021 at 04:02:13PM +0000, Ciara Loftus wrote:
> > Prior to this commit individual xsk tests were launched from the
> > shell script 'test_xsk.sh'. When adding a new test type, two new test
> > configurations had to be added to this file - one for each of the
> > supported XDP 'modes' (skb or drv). Should zero copy support be added to
> > the xsk selftest framework in the future, three new test configurations
> > would need to be added for each new test type. Each new test type also
> > typically requires new CLI arguments for the xdpxceiver program.
> >
> > This commit aims to reduce the overhead of adding new tests, by launching
> > the test configurations from within the xdpxceiver program itself, using
> > simple loops. Every test is run every time the C program is executed. Many
> > of the CLI arguments can be removed as a result.
> >
> > Signed-off-by: Ciara Loftus <[email-masked]>
> > ---
> >  tools/testing/selftests/bpf/test_xsk.sh    | 112 +-----------
> >  tools/testing/selftests/bpf/xdpxceiver.c   | 199 ++++++++++++---------
> >  tools/testing/selftests/bpf/xdpxceiver.h   |  27 ++-
> >  tools/testing/selftests/bpf/xsk_prereqs.sh |  24 +--
> >  4 files changed, 139 insertions(+), 223 deletions(-)
> >
> 
> Good cleanup! I have a series of fixes/cleanups as well and I need to
> introduce a new test over here, so your work makes it easier for me.
> 
> One nit below and once you address Bjorn's request, then feel free to add
> my:

Thanks Björn and Maciej for the feedback. Will include your suggestions in the v2.
I discovered some extra things to tweak for the v2 but hope to have it up shortly.

Thanks,
Ciara

> 
> Reviewed-by: Maciej Fijalkowski <[email-masked]>
> 
> [...]
> 
> > +static int configure_skb(void)
> > +{
> > +
> > +	char cmd[80];
> > +
> > +	snprintf(cmd, sizeof(cmd), "ip link set dev %s xdpdrv off", ifdict[0]-
> >ifname);
> > +	if (system(cmd)) {
> > +		ksft_test_result_fail("Failed to configure native mode on
> iface %s\n",
> > +						ifdict[0]->ifname);
> > +		return -1;
> > +	}
> > +	snprintf(cmd, sizeof(cmd), "ip netns exec %s ip link set dev %s
> xdpdrv off",
> > +					ifdict[1]->nsname, ifdict[1]->ifname);
> > +	if (system(cmd)) {
> > +		ksft_test_result_fail("Failed to configure native mode on
> iface/ns %s\n",
> > +						ifdict[1]->ifname, ifdict[1]-
> >nsname);
> > +		return -1;
> > +	}
> > +
> > +	cur_mode = TEST_MODE_SKB;
> > +
> > +	return 0;
> > +
> > +}
> > +
> > +static int configure_drv(void)
> > +{
> > +	char cmd[80];
> > +
> > +	snprintf(cmd, sizeof(cmd), "ip link set dev %s xdpgeneric off",
> ifdict[0]->ifname);
> > +	if (system(cmd)) {
> > +		ksft_test_result_fail("Failed to configure native mode on
> iface %s\n",
> > +						ifdict[0]->ifname);
> > +		return -1;
> > +	}
> > +	snprintf(cmd, sizeof(cmd), "ip netns exec %s ip link set dev %s
> xdpgeneric off",
> > +					ifdict[1]->nsname, ifdict[1]->ifname);
> > +	if (system(cmd)) {
> > +		ksft_test_result_fail("Failed to configure native mode on
> iface/ns %s\n",
> > +						ifdict[1]->ifname, ifdict[1]-
> >nsname);
> > +		return -1;
> > +	}
> > +
> > +	cur_mode = TEST_MODE_DRV;
> > +
> > +	return 0;
> > +}
> > +
> > +static void run_pkt_test(int mode, int type)
> > +{
> > +	test_type = type;
> > +
> > +	/* reset defaults after potential previous test */
> > +	xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
> > +	pkt_counter = 0;
> > +	switching_notify = 0;
> > +	bidi_pass = 0;
> > +	prev_pkt = -1;
> > +	ifdict[0]->fv.vector = tx;
> > +	ifdict[1]->fv.vector = rx;
> > +
> > +	switch (mode) {
> > +	case (TEST_MODE_SKB):
> > +		if (cur_mode != TEST_MODE_SKB)
> > +			configure_skb();
> 
> Should you check a return value over here?
> 
> > +		xdp_flags |= XDP_FLAGS_SKB_MODE;
> > +		uut = TEST_MODE_SKB;
> > +		break;
> > +	case (TEST_MODE_DRV):
> > +		if (cur_mode != TEST_MODE_DRV)
> > +			configure_drv();
> 
> ditto
> 
> > +		xdp_flags |= XDP_FLAGS_DRV_MODE;
> > +		uut = TEST_MODE_DRV;
> > +		break;
> > +	default:
> > +		break;
> > +	}
> > +
> > +	pthread_init_mutex();
> > +
> > +	if ((test_type != TEST_TYPE_TEARDOWN) && (test_type !=
> TEST_TYPE_BIDI))
> > +		testapp_validate();
> > +	else
> > +		testapp_sockets();
> > +
> > +	pthread_destroy_mutex();
> > +}
> > +
> >  int main(int argc, char **argv)
> >  {
> >  	struct rlimit _rlim = { RLIM_INFINITY, RLIM_INFINITY };
> > @@ -1021,6 +1062,7 @@ int main(int argc, char **argv)
> >  	const char *IP2 = "192.168.100.161";
> >  	u16 UDP_DST_PORT = 2020;
> >  	u16 UDP_SRC_PORT = 2121;
> > +	int i, j;
> >
> >  	ifaceconfig = malloc(sizeof(struct ifaceconfigobj));
> >  	memcpy(ifaceconfig->dst_mac, MAC1, ETH_ALEN);
> > @@ -1046,24 +1088,19 @@ int main(int argc, char **argv)
> >
> >  	init_iface_config(ifaceconfig);
> >
> > -	pthread_init_mutex();
> > +	ksft_set_plan(TEST_MODE_MAX * TEST_TYPE_MAX);
> >
> > -	ksft_set_plan(1);
> > +	configure_skb();
> > +	cur_mode = TEST_MODE_SKB;
> >
> > -	if (!opt_teardown && !opt_bidi) {
> > -		testapp_validate();
> > -	} else if (opt_teardown && opt_bidi) {
> > -		ksft_test_result_fail("ERROR: parameters -T and -B cannot
> be used together\n");
> > -		ksft_exit_xfail();
> > -	} else {
> > -		testapp_sockets();
> > +	for (i = 0; i < TEST_MODE_MAX; i++) {
> > +		for (j = 0; j < TEST_TYPE_MAX; j++)
> > +			run_pkt_test(i, j);
> >  	}
> >
> >  	for (int i = 0; i < MAX_INTERFACES; i++)
> >  		free(ifdict[i]);
> >
> > -	pthread_destroy_mutex();
> > -
> >  	ksft_exit_pass();
> >
> >  	return 0;