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Commit cc14499b authored by Yu Xiao's avatar Yu Xiao Committed by Greg Kroah-Hartman
Browse files

nfp: bpf: relax prog rejection for mtu check through max_pkt_offset 



[ Upstream commit 90a881fc352a953f1c8beb61977a2db0818157d4 ]

MTU change is refused whenever the value of new MTU is bigger than
the max packet bytes that fits in NFP Cluster Target Memory (CTM).
However, an eBPF program doesn't always need to access the whole
packet data.

The maximum direct packet access (DPA) offset has always been
caculated by verifier and stored in the max_pkt_offset field of prog
aux data.

Signed-off-by: default avatarYu Xiao <yu.xiao@corigine.com>
Reviewed-by: default avatarYinjun Zhang <yinjun.zhang@corigine.com>
Reviewed-by: default avatarNiklas Soderlund <niklas.soderlund@corigine.com>
Signed-off-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent a62d4308

drivers/net/ethernet/netronome/nfp/bpf/main.c

+11 −5
Original line number Diff line number Diff line
@@ -182,15 +182,21 @@ static int 
nfp_bpf_check_mtu(struct nfp_app *app, struct net_device *netdev, int new_mtu)

{

	struct nfp_net *nn = netdev_priv(netdev);

	unsigned int max_mtu;

	struct nfp_bpf_vnic *bv;

	struct bpf_prog *prog;



	if (~nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)

		return 0;



	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;

	if (new_mtu > max_mtu) {

		nn_info(nn, "BPF offload active, MTU over %u not supported\n",

			max_mtu);

	if (nn->xdp_hw.prog) {

		prog = nn->xdp_hw.prog;

	} else {

		bv = nn->app_priv;

		prog = bv->tc_prog;

	}



	if (nfp_bpf_offload_check_mtu(nn, prog, new_mtu)) {

		nn_info(nn, "BPF offload active, potential packet access beyond hardware packet boundary");

		return -EBUSY;

	}

	return 0;

drivers/net/ethernet/netronome/nfp/bpf/main.h

+2 −0
Original line number Diff line number Diff line
@@ -560,6 +560,8 @@ bool nfp_is_subprog_start(struct nfp_insn_meta *meta); 
void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog);

int nfp_bpf_jit(struct nfp_prog *prog);

bool nfp_bpf_supported_opcode(u8 code);

bool nfp_bpf_offload_check_mtu(struct nfp_net *nn, struct bpf_prog *prog,

			       unsigned int mtu);



int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx,

		    int prev_insn_idx);

drivers/net/ethernet/netronome/nfp/bpf/offload.c

+13 −4
Original line number Diff line number Diff line
@@ -477,19 +477,28 @@ int nfp_bpf_event_output(struct nfp_app_bpf *bpf, const void *data, 
	return 0;

}



bool nfp_bpf_offload_check_mtu(struct nfp_net *nn, struct bpf_prog *prog,

			       unsigned int mtu)

{

	unsigned int fw_mtu, pkt_off;



	fw_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;

	pkt_off = min(prog->aux->max_pkt_offset, mtu);



	return fw_mtu < pkt_off;

}



static int

nfp_net_bpf_load(struct nfp_net *nn, struct bpf_prog *prog,

		 struct netlink_ext_ack *extack)

{

	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;

	unsigned int fw_mtu, pkt_off, max_stack, max_prog_len;

	unsigned int max_stack, max_prog_len;

	dma_addr_t dma_addr;

	void *img;

	int err;



	fw_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;

	pkt_off = min(prog->aux->max_pkt_offset, nn->dp.netdev->mtu);

	if (fw_mtu < pkt_off) {

	if (nfp_bpf_offload_check_mtu(nn, prog, nn->dp.netdev->mtu)) {

		NL_SET_ERR_MSG_MOD(extack, "BPF offload not supported with potential packet access beyond HW packet split boundary");

		return -EOPNOTSUPP;

	}