vmxnet3: add support for RSS kernel option

We observe at least one problem: if a UDP socket is connect(2)-ed, then a
received packet that matches the connection cannot be matched to the
corresponding PCB because of an incorrect flow ID.  That was oberved for DNS
requests from the libc resolver.  We got this problem because FreeBSD
r343291 enabled code that can set rsstype of received packets to values
other than M_HASHTYPE_OPAQUE_HASH.  Earlier that code was under 'ifdef
notyet'.

The essence of this change is to use the system-wide RSS key instead of
some historic hardcoded key when the software RSS is enabled and it is
configured to use Toeplitz algorithm (the default).
In all other cases, the driver reports the opaque hash type for received
packets while still using Toeplitz algorithm with the internal key.

PR:		242890
Reviewed by:	pkelsey
Sponsored by:	Panzura
Differential Revision: https://reviews.freebsd.org/D23147
This commit is contained in:
Andriy Gapon 2020-01-23 11:05:03 +00:00
parent 8427dd0899
commit 281cab4d9e
3 changed files with 77 additions and 27 deletions

View File

@ -23,6 +23,8 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_rss.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
@ -46,6 +48,9 @@ __FBSDID("$FreeBSD$");
#include <net/if_media.h>
#include <net/if_vlan_var.h>
#include <net/iflib.h>
#ifdef RSS
#include <net/rss_config.h>
#endif
#include <netinet/in_systm.h>
#include <netinet/in.h>
@ -1140,6 +1145,9 @@ vmxnet3_reinit_rss_shared_data(struct vmxnet3_softc *sc)
struct vmxnet3_driver_shared *ds;
if_softc_ctx_t scctx;
struct vmxnet3_rss_shared *rss;
#ifdef RSS
uint8_t rss_algo;
#endif
int i;
ds = sc->vmx_ds;
@ -1152,10 +1160,29 @@ vmxnet3_reinit_rss_shared_data(struct vmxnet3_softc *sc)
rss->hash_func = UPT1_RSS_HASH_FUNC_TOEPLITZ;
rss->hash_key_size = UPT1_RSS_MAX_KEY_SIZE;
rss->ind_table_size = UPT1_RSS_MAX_IND_TABLE_SIZE;
memcpy(rss->hash_key, rss_key, UPT1_RSS_MAX_KEY_SIZE);
for (i = 0; i < UPT1_RSS_MAX_IND_TABLE_SIZE; i++)
rss->ind_table[i] = i % scctx->isc_nrxqsets;
#ifdef RSS
/*
* If the software RSS is configured to anything else other than
* Toeplitz, then just do Toeplitz in "hardware" for the sake of
* the packet distribution, but report the hash as opaque to
* disengage from the software RSS.
*/
rss_algo = rss_gethashalgo();
if (rss_algo == RSS_HASH_TOEPLITZ) {
rss_getkey(rss->hash_key);
for (i = 0; i < UPT1_RSS_MAX_IND_TABLE_SIZE; i++) {
rss->ind_table[i] = rss_get_indirection_to_bucket(i) %
scctx->isc_nrxqsets;
}
sc->vmx_flags |= VMXNET3_FLAG_SOFT_RSS;
} else
#endif
{
memcpy(rss->hash_key, rss_key, UPT1_RSS_MAX_KEY_SIZE);
for (i = 0; i < UPT1_RSS_MAX_IND_TABLE_SIZE; i++)
rss->ind_table[i] = i % scctx->isc_nrxqsets;
sc->vmx_flags &= ~VMXNET3_FLAG_SOFT_RSS;
}
}
static void
@ -1499,29 +1526,50 @@ vmxnet3_isc_rxd_pkt_get(void *vsc, if_rxd_info_t ri)
KASSERT(rxcd->sop, ("%s: expected sop", __func__));
/*
* RSS and flow ID
* RSS and flow ID.
* Types other than M_HASHTYPE_NONE and M_HASHTYPE_OPAQUE_HASH should
* be used only if the software RSS is enabled and it uses the same
* algorithm and the hash key as the "hardware". If the software RSS
* is not enabled, then it's simply pointless to use those types.
* If it's enabled but with different parameters, then hash values will
* not match.
*/
ri->iri_flowid = rxcd->rss_hash;
switch (rxcd->rss_type) {
case VMXNET3_RCD_RSS_TYPE_NONE:
ri->iri_flowid = ri->iri_qsidx;
ri->iri_rsstype = M_HASHTYPE_NONE;
break;
case VMXNET3_RCD_RSS_TYPE_IPV4:
ri->iri_rsstype = M_HASHTYPE_RSS_IPV4;
break;
case VMXNET3_RCD_RSS_TYPE_TCPIPV4:
ri->iri_rsstype = M_HASHTYPE_RSS_TCP_IPV4;
break;
case VMXNET3_RCD_RSS_TYPE_IPV6:
ri->iri_rsstype = M_HASHTYPE_RSS_IPV6;
break;
case VMXNET3_RCD_RSS_TYPE_TCPIPV6:
ri->iri_rsstype = M_HASHTYPE_RSS_TCP_IPV6;
break;
default:
ri->iri_rsstype = M_HASHTYPE_OPAQUE_HASH;
break;
#ifdef RSS
if ((sc->vmx_flags & VMXNET3_FLAG_SOFT_RSS) != 0) {
switch (rxcd->rss_type) {
case VMXNET3_RCD_RSS_TYPE_NONE:
ri->iri_flowid = ri->iri_qsidx;
ri->iri_rsstype = M_HASHTYPE_NONE;
break;
case VMXNET3_RCD_RSS_TYPE_IPV4:
ri->iri_rsstype = M_HASHTYPE_RSS_IPV4;
break;
case VMXNET3_RCD_RSS_TYPE_TCPIPV4:
ri->iri_rsstype = M_HASHTYPE_RSS_TCP_IPV4;
break;
case VMXNET3_RCD_RSS_TYPE_IPV6:
ri->iri_rsstype = M_HASHTYPE_RSS_IPV6;
break;
case VMXNET3_RCD_RSS_TYPE_TCPIPV6:
ri->iri_rsstype = M_HASHTYPE_RSS_TCP_IPV6;
break;
default:
ri->iri_rsstype = M_HASHTYPE_OPAQUE_HASH;
break;
}
} else
#endif
{
switch (rxcd->rss_type) {
case VMXNET3_RCD_RSS_TYPE_NONE:
ri->iri_flowid = ri->iri_qsidx;
ri->iri_rsstype = M_HASHTYPE_NONE;
break;
default:
ri->iri_rsstype = M_HASHTYPE_OPAQUE_HASH;
break;
}
}
/* VLAN */

View File

@ -113,6 +113,8 @@ struct vmxnet3_softc {
struct vmxnet3_driver_shared *vmx_ds;
uint32_t vmx_flags;
#define VMXNET3_FLAG_RSS 0x0002
#define VMXNET3_FLAG_SOFT_RSS 0x0004 /* Software RSS is enabled with
compatible algorithm. */
struct vmxnet3_rxqueue *vmx_rxq;
struct vmxnet3_txqueue *vmx_txq;

View File

@ -28,6 +28,6 @@
KMOD= if_vmx
SRCS= if_vmx.c
SRCS+= bus_if.h device_if.h pci_if.h ifdi_if.h
SRCS+= opt_inet.h opt_inet6.h
SRCS+= opt_inet.h opt_inet6.h opt_rss.h
.include <bsd.kmod.mk>