Skip to content

Commit

Permalink
iflib: initialize netmap with the correct number of descriptors
Browse files Browse the repository at this point in the history 
In case the network device has a RX or TX control queue, the correct
number of TX/RX descriptors is contained in the second entry of the
isc_ntxd (or isc_nrxd) array, rather than in the first entry.
This case is correctly handled by iflib_device_register() and
iflib_pseudo_register(), but not by iflib_netmap_attach().
If the first entry is larger than the second, this can result in a
panic. This change fixes the bug by introducing two helper functions
that also lead to some code simplification.

PR:	247647
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D25541
  • Loading branch information
Vincenzo Maffione authored and Vincenzo Maffione committed Jul 20, 2020
1 parent 3b41d99 commit ac11d85
Showing 1 changed file with 38 additions and 22 deletions.
60 changes: 38 additions & 22 deletions sys/net/iflib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -730,6 +730,26 @@ MTX_SYSINIT(iflib_cpu_offset, &cpu_offset_mtx, "iflib_cpu_offset lock",

DEBUGNET_DEFINE(iflib);

static int
iflib_num_rx_descs(if_ctx_t ctx)
{
if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
if_shared_ctx_t sctx = ctx->ifc_sctx;
uint16_t first_rxq = (sctx->isc_flags & IFLIB_HAS_RXCQ) ? 1 : 0;

return scctx->isc_nrxd[first_rxq];
}

static int
iflib_num_tx_descs(if_ctx_t ctx)
{
if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
if_shared_ctx_t sctx = ctx->ifc_sctx;
uint16_t first_txq = (sctx->isc_flags & IFLIB_HAS_TXCQ) ? 1 : 0;

return scctx->isc_ntxd[first_txq];
}

#ifdef DEV_NETMAP
#include <sys/selinfo.h>
#include <net/netmap.h>
Expand Down Expand Up @@ -1165,7 +1185,6 @@ static int
iflib_netmap_attach(if_ctx_t ctx)
{
struct netmap_adapter na;
if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;

bzero(&na, sizeof(na));

Expand All @@ -1174,8 +1193,8 @@ iflib_netmap_attach(if_ctx_t ctx)
MPASS(ctx->ifc_softc_ctx.isc_ntxqsets);
MPASS(ctx->ifc_softc_ctx.isc_nrxqsets);

na.num_tx_desc = scctx->isc_ntxd[0];
na.num_rx_desc = scctx->isc_nrxd[0];
na.num_tx_desc = iflib_num_tx_descs(ctx);
na.num_rx_desc = iflib_num_rx_descs(ctx);
na.nm_txsync = iflib_netmap_txsync;
na.nm_rxsync = iflib_netmap_rxsync;
na.nm_register = iflib_netmap_register;
Expand Down Expand Up @@ -4590,7 +4609,7 @@ iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ct
kobjop_desc_t kobj_desc;
kobj_method_t *kobj_method;
int err, msix, rid;
uint16_t main_rxq, main_txq;
int num_txd, num_rxd;

ctx = malloc(sizeof(* ctx), M_IFLIB, M_WAITOK|M_ZERO);

Expand Down Expand Up @@ -4640,21 +4659,20 @@ iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ct
if (scctx->isc_nrxqsets == 0 || (scctx->isc_nrxqsets_max && scctx->isc_nrxqsets_max < scctx->isc_nrxqsets))
scctx->isc_nrxqsets = scctx->isc_nrxqsets_max;

main_txq = (sctx->isc_flags & IFLIB_HAS_TXCQ) ? 1 : 0;
main_rxq = (sctx->isc_flags & IFLIB_HAS_RXCQ) ? 1 : 0;
num_txd = iflib_num_tx_descs(ctx);
num_rxd = iflib_num_rx_descs(ctx);

/* XXX change for per-queue sizes */
device_printf(dev, "Using %d TX descriptors and %d RX descriptors\n",
scctx->isc_ntxd[main_txq], scctx->isc_nrxd[main_rxq]);
num_txd, num_rxd);

if (scctx->isc_tx_nsegments > scctx->isc_ntxd[main_txq] /
MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_nsegments = max(1, scctx->isc_ntxd[main_txq] /
if (scctx->isc_tx_nsegments > num_txd / MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_nsegments = max(1, num_txd /
MAX_SINGLE_PACKET_FRACTION);
if (scctx->isc_tx_tso_segments_max > scctx->isc_ntxd[main_txq] /
if (scctx->isc_tx_tso_segments_max > num_txd /
MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_tso_segments_max = max(1,
scctx->isc_ntxd[main_txq] / MAX_SINGLE_PACKET_FRACTION);
num_txd / MAX_SINGLE_PACKET_FRACTION);

/* TSO parameters - dig these out of the data sheet - simply correspond to tag setup */
if (if_getcapabilities(ifp) & IFCAP_TSO) {
Expand Down Expand Up @@ -4831,14 +4849,13 @@ int
iflib_pseudo_register(device_t dev, if_shared_ctx_t sctx, if_ctx_t *ctxp,
struct iflib_cloneattach_ctx *clctx)
{
int num_txd, num_rxd;
int err;
if_ctx_t ctx;
if_t ifp;
if_softc_ctx_t scctx;
int i;
void *sc;
uint16_t main_txq;
uint16_t main_rxq;

ctx = malloc(sizeof(*ctx), M_IFLIB, M_WAITOK|M_ZERO);
sc = malloc(sctx->isc_driver->size, M_IFLIB, M_WAITOK|M_ZERO);
Expand Down Expand Up @@ -4924,21 +4941,20 @@ iflib_pseudo_register(device_t dev, if_shared_ctx_t sctx, if_ctx_t *ctxp,
if (scctx->isc_nrxqsets == 0 || (scctx->isc_nrxqsets_max && scctx->isc_nrxqsets_max < scctx->isc_nrxqsets))
scctx->isc_nrxqsets = scctx->isc_nrxqsets_max;

main_txq = (sctx->isc_flags & IFLIB_HAS_TXCQ) ? 1 : 0;
main_rxq = (sctx->isc_flags & IFLIB_HAS_RXCQ) ? 1 : 0;
num_txd = iflib_num_tx_descs(ctx);
num_rxd = iflib_num_rx_descs(ctx);

/* XXX change for per-queue sizes */
device_printf(dev, "Using %d TX descriptors and %d RX descriptors\n",
scctx->isc_ntxd[main_txq], scctx->isc_nrxd[main_rxq]);
num_txd, num_rxd);

if (scctx->isc_tx_nsegments > scctx->isc_ntxd[main_txq] /
MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_nsegments = max(1, scctx->isc_ntxd[main_txq] /
if (scctx->isc_tx_nsegments > num_txd / MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_nsegments = max(1, num_txd /
MAX_SINGLE_PACKET_FRACTION);
if (scctx->isc_tx_tso_segments_max > scctx->isc_ntxd[main_txq] /
if (scctx->isc_tx_tso_segments_max > num_txd /
MAX_SINGLE_PACKET_FRACTION)
scctx->isc_tx_tso_segments_max = max(1,
scctx->isc_ntxd[main_txq] / MAX_SINGLE_PACKET_FRACTION);
num_txd / MAX_SINGLE_PACKET_FRACTION);

/* TSO parameters - dig these out of the data sheet - simply correspond to tag setup */
if (if_getcapabilities(ifp) & IFCAP_TSO) {
Expand Down

0 comments on commit ac11d85

Please sign in to comment.