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vmxnet3: skip zero-length descriptor in the middle of a packet

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Passing up such descriptors to iflib is obviously wasteful.
But the main conern is that we may overrun iri_frags array because of
them.  That's been observed in practice.

Also, assert that the number of fragments / descriptors / segments is
less than IFLIB_MAX_RX_SEGS.

Reviewed by:	gallatin, pkelsey
MFC after:	3 weeks
Sponsored by:	Panzura LLC
Differential Revision:	https://reviews.freebsd.org/D33189
This commit is contained in:
Andriy Gapon 2021-12-06 09:59:28 +02:00
parent cd6f0b4769
commit 9c612a5d0a
2 changed files with 18 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
sys/dev/vmware/vmxnet3/if_vmx.c
View File

@ -1503,8 +1503,6 @@ vmxnet3_isc_rxd_pkt_get(void *vsc, if_rxd_info_t ri)
struct vmxnet3_rxqueue *rxq;
struct vmxnet3_comp_ring *rxc;
struct vmxnet3_rxcompdesc *rxcd;
struct vmxnet3_rxring *rxr;
struct vmxnet3_rxdesc *rxd;
if_rxd_frag_t frag;
int cqidx;
uint16_t total_len;
@ -1604,16 +1602,19 @@ vmxnet3_isc_rxd_pkt_get(void *vsc, if_rxd_info_t ri)
rxcd = &rxc->vxcr_u.rxcd[cqidx];
KASSERT(rxcd->gen == rxc->vxcr_gen,
("%s: generation mismatch", __func__));
flid = (rxcd->qid >= scctx->isc_nrxqsets) ? 1 : 0;
rxr = &rxq->vxrxq_cmd_ring[flid];
rxd = &rxr->vxrxr_rxd[rxcd->rxd_idx];
frag = &ri->iri_frags[nfrags];
frag->irf_flid = flid;
frag->irf_idx = rxcd->rxd_idx;
frag->irf_len = rxcd->len;
total_len += rxcd->len;
nfrags++;
KASSERT(nfrags < IFLIB_MAX_RX_SEGS,
("%s: too many fragments", __func__));
if (__predict_true(rxcd->len != 0)) {
frag = &ri->iri_frags[nfrags];
flid = (rxcd->qid >= scctx->isc_nrxqsets) ? 1 : 0;
frag->irf_flid = flid;
frag->irf_idx = rxcd->rxd_idx;
frag->irf_len = rxcd->len;
total_len += rxcd->len;
nfrags++;
} else {
rxc->vcxr_zero_length_frag++;
}
if (++cqidx == rxc->vxcr_ndesc) {
cqidx = 0;
rxc->vxcr_gen ^= 1;
@ -1885,6 +1886,7 @@ vmxnet3_rxinit(struct vmxnet3_softc *sc, struct vmxnet3_rxqueue *rxq)
rxc->vxcr_next = 0;
rxc->vxcr_gen = VMXNET3_INIT_GEN;
rxc->vxcr_zero_length = 0;
rxc->vcxr_zero_length_frag = 0;
rxc->vxcr_pkt_errors = 0;
/*
* iflib has zeroed out the descriptor array during the prior attach
@ -2365,6 +2367,9 @@ vmxnet3_setup_debug_sysctl(struct vmxnet3_softc *sc,
&rxq->vxrxq_comp_ring.vxcr_gen, 0, "");
SYSCTL_ADD_U64(ctx, list, OID_AUTO, "comp_zero_length", CTLFLAG_RD,
&rxq->vxrxq_comp_ring.vxcr_zero_length, 0, "");
SYSCTL_ADD_U64(ctx, list, OID_AUTO, "comp_zero_length_frag",
CTLFLAG_RD, &rxq->vxrxq_comp_ring.vcxr_zero_length_frag,
0, "");
SYSCTL_ADD_U64(ctx, list, OID_AUTO, "comp_pkt_errors", CTLFLAG_RD,
&rxq->vxrxq_comp_ring.vxcr_pkt_errors, 0, "");
}

1
sys/dev/vmware/vmxnet3/if_vmxvar.h
View File

@ -81,6 +81,7 @@ struct vmxnet3_comp_ring {
int vxcr_gen;
bus_addr_t vxcr_paddr;
uint64_t vxcr_zero_length;
uint64_t vcxr_zero_length_frag;
uint64_t vxcr_pkt_errors;
};