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Introduce a per-VNET flag to enable/disable netisr prcessing on that VNET.

Browse Source 
Add accessor functions to toggle the state per VNET.
The base system (vnet0) will always enable itself with the normal
registration. We will share the registered protocol handlers in all
VNETs minimising duplication and management.
Upon disabling netisr processing for a VNET drain the netisr queue from
packets for that VNET.

Update netisr consumers to (de)register on a per-VNET start/teardown using
VNET_SYS(UN)INIT functionality.

The change should be transparent for non-VIMAGE kernels.

Reviewed by:	gnn (, hiren)
Obtained from:	projects/vnet
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D6691
This commit is contained in:
Bjoern A. Zeeb 2016-06-03 13:57:10 +00:00
parent 3e0522bc8f
commit 484149def8
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=301270
9 changed files with 272 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
share/man/man9/netisr.9
View File

@ -27,7 +27,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd January 11, 2015
.Dd June 3, 2016
.Dt NETISR 9
.Os
.Sh NAME
@ -61,6 +61,16 @@
.Fn netisr_get_cpucount "void"
.Ft u_int
.Fn netisr_get_cpuid "u_int cpunumber"
.Pp
With optional virtual network stack support enabled via the following kernel
compile option:
.Bd -ragged -offset indent
.Cd "options VIMAGE"
.Ed
.Ft void
.Fn netisr_register_vnet "const struct netisr_handler *nhp"
.Ft void
.Fn netisr_unregister_vnet "const struct netisr_handler *nhp"
.Sh DESCRIPTION
The
.Nm
@ -80,6 +90,16 @@ and may also manage queue limits and statistics using the
and
.Fn netisr_setqlimit .
.Pp
In case of VIMAGE kernels each virtual network stack (vnet), that is not the
default base system network stack, calls
.Fn netisr_register_vnet
and
.Fn netisr_unregister_vnet
to enable or disable packet processing by the
.Nm
for each protocol.
Disabling will also purge any outstanding packet from the protocol queue.
.Pp
.Nm
supports multi-processor execution of handlers, and relies on a combination
of source ordering and protocol-specific ordering and work-placement

6
sys/net/if_epair.c
View File

@ -959,6 +959,9 @@ vnet_epair_init(const void *unused __unused)
V_epair_cloner = if_clone_advanced(epairname, 0,
epair_clone_match, epair_clone_create, epair_clone_destroy);
#ifdef VIMAGE
netisr_register_vnet(&epair_nh);
#endif
}
VNET_SYSINIT(vnet_epair_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
vnet_epair_init, NULL);
@ -967,6 +970,9 @@ static void
vnet_epair_uninit(const void *unused __unused)
{
#ifdef VIMAGE
netisr_unregister_vnet(&epair_nh);
#endif
if_clone_detach(V_epair_cloner);
}
VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,

18
sys/net/if_ethersubr.c
View File

@ -702,12 +702,16 @@ vnet_ether_init(__unused void *arg)
if ((i = pfil_head_register(&V_link_pfil_hook)) != 0)
printf("%s: WARNING: unable to register pfil link hook, "
"error %d\n", __func__, i);
#ifdef VIMAGE
netisr_register_vnet(&ether_nh);
#endif
}
VNET_SYSINIT(vnet_ether_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
vnet_ether_init, NULL);
#ifdef VIMAGE
static void
vnet_ether_destroy(__unused void *arg)
vnet_ether_pfil_destroy(__unused void *arg)
{
int i;
@ -715,8 +719,18 @@ vnet_ether_destroy(__unused void *arg)
printf("%s: WARNING: unable to unregister pfil link hook, "
"error %d\n", __func__, i);
}
VNET_SYSUNINIT(vnet_ether_pfil_uninit, SI_SUB_PROTO_PFIL, SI_ORDER_ANY,
vnet_ether_pfil_destroy, NULL);
static void
vnet_ether_destroy(__unused void *arg)
{
netisr_unregister_vnet(&ether_nh);
}
VNET_SYSUNINIT(vnet_ether_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
vnet_ether_destroy, NULL);
#endif
@ -740,7 +754,9 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
* so assert it is correct here.
*/
KASSERT(m->m_pkthdr.rcvif == ifp, ("%s: ifnet mismatch", __func__));
CURVNET_SET_QUIET(ifp->if_vnet);
netisr_dispatch(NETISR_ETHER, m);
CURVNET_RESTORE();
m = mn;
}
}

150
sys/net/netisr.c
View File

@ -210,6 +210,23 @@ SYSCTL_UINT(_net_isr, OID_AUTO, maxprot, CTLFLAG_RD,
*/
static struct netisr_proto netisr_proto[NETISR_MAXPROT];
#ifdef VIMAGE
/*
* The netisr_enable array describes a per-VNET flag for registered
* protocols on whether this netisr is active in this VNET or not.
* netisr_register() will automatically enable the netisr for the
* default VNET and all currently active instances.
* netisr_unregister() will disable all active VNETs, including vnet0.
* Individual network stack instances can be enabled/disabled by the
* netisr_(un)register _vnet() functions.
* With this we keep the one netisr_proto per protocol but add a
* mechanism to stop netisr processing for vnet teardown.
* Apart from that we expect a VNET to always be enabled.
*/
static VNET_DEFINE(u_int, netisr_enable[NETISR_MAXPROT]);
#define V_netisr_enable VNET(netisr_enable)
#endif
/*
* Per-CPU workstream data. See netisr_internal.h for more details.
*/
@ -352,6 +369,7 @@ sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS)
void
netisr_register(const struct netisr_handler *nhp)
{
VNET_ITERATOR_DECL(vnet_iter);
struct netisr_work *npwp;
const char *name;
u_int i, proto;
@ -420,6 +438,22 @@ netisr_register(const struct netisr_handler *nhp)
bzero(npwp, sizeof(*npwp));
npwp->nw_qlimit = netisr_proto[proto].np_qlimit;
}
#ifdef VIMAGE
/*
* Test that we are in vnet0 and have a curvnet set.
*/
KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
KASSERT(IS_DEFAULT_VNET(curvnet), ("%s: curvnet %p is not vnet0 %p",
__func__, curvnet, vnet0));
VNET_LIST_RLOCK_NOSLEEP();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
V_netisr_enable[proto] = 1;
CURVNET_RESTORE();
}
VNET_LIST_RUNLOCK_NOSLEEP();
#endif
NETISR_WUNLOCK();
}
@ -584,6 +618,7 @@ netisr_drain_proto(struct netisr_work *npwp)
void
netisr_unregister(const struct netisr_handler *nhp)
{
VNET_ITERATOR_DECL(vnet_iter);
struct netisr_work *npwp;
#ifdef INVARIANTS
const char *name;
@ -602,6 +637,16 @@ netisr_unregister(const struct netisr_handler *nhp)
("%s(%u): protocol not registered for %s", __func__, proto,
name));
#ifdef VIMAGE
VNET_LIST_RLOCK_NOSLEEP();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
V_netisr_enable[proto] = 0;
CURVNET_RESTORE();
}
VNET_LIST_RUNLOCK_NOSLEEP();
#endif
netisr_proto[proto].np_name = NULL;
netisr_proto[proto].np_handler = NULL;
netisr_proto[proto].np_m2flow = NULL;
@ -616,6 +661,97 @@ netisr_unregister(const struct netisr_handler *nhp)
NETISR_WUNLOCK();
}
#ifdef VIMAGE
void
netisr_register_vnet(const struct netisr_handler *nhp)
{
u_int proto;
proto = nhp->nh_proto;
KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
KASSERT(proto < NETISR_MAXPROT,
("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
NETISR_WLOCK();
KASSERT(netisr_proto[proto].np_handler != NULL,
("%s(%u): protocol not registered for %s", __func__, proto,
nhp->nh_name));
V_netisr_enable[proto] = 1;
NETISR_WUNLOCK();
}
static void
netisr_drain_proto_vnet(struct vnet *vnet, u_int proto)
{
struct netisr_workstream *nwsp;
struct netisr_work *npwp;
struct mbuf *m, *mp, *n, *ne;
u_int i;
KASSERT(vnet != NULL, ("%s: vnet is NULL", __func__));
NETISR_LOCK_ASSERT();
CPU_FOREACH(i) {
nwsp = DPCPU_ID_PTR(i, nws);
if (nwsp->nws_intr_event == NULL)
continue;
npwp = &nwsp->nws_work[proto];
NWS_LOCK(nwsp);
/*
* Rather than dissecting and removing mbufs from the middle
* of the chain, we build a new chain if the packet stays and
* update the head and tail pointers at the end. All packets
* matching the given vnet are freed.
*/
m = npwp->nw_head;
n = ne = NULL;
while (m != NULL) {
mp = m;
m = m->m_nextpkt;
mp->m_nextpkt = NULL;
if (mp->m_pkthdr.rcvif->if_vnet != vnet) {
if (n == NULL) {
n = ne = mp;
} else {
ne->m_nextpkt = mp;
ne = mp;
}
continue;
}
/* This is a packet in the selected vnet. Free it. */
npwp->nw_len--;
m_freem(mp);
}
npwp->nw_head = n;
npwp->nw_tail = ne;
NWS_UNLOCK(nwsp);
}
}
void
netisr_unregister_vnet(const struct netisr_handler *nhp)
{
u_int proto;
proto = nhp->nh_proto;
KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
KASSERT(proto < NETISR_MAXPROT,
("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
NETISR_WLOCK();
KASSERT(netisr_proto[proto].np_handler != NULL,
("%s(%u): protocol not registered for %s", __func__, proto,
nhp->nh_name));
V_netisr_enable[proto] = 0;
netisr_drain_proto_vnet(curvnet, proto);
NETISR_WUNLOCK();
}
#endif
/*
* Compose the global and per-protocol policies on dispatch, and return the
* dispatch policy to use.
@ -906,6 +1042,13 @@ netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m)
KASSERT(netisr_proto[proto].np_handler != NULL,
("%s: invalid proto %u", __func__, proto));
#ifdef VIMAGE
if (V_netisr_enable[proto] == 0) {
m_freem(m);
return (ENOPROTOOPT);
}
#endif
m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_DEFERRED,
source, m, &cpuid);
if (m != NULL) {
@ -952,6 +1095,13 @@ netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m)
KASSERT(npp->np_handler != NULL, ("%s: invalid proto %u", __func__,
proto));
#ifdef VIMAGE
if (V_netisr_enable[proto] == 0) {
m_freem(m);
return (ENOPROTOOPT);
}
#endif
dispatch_policy = netisr_get_dispatch(npp);
if (dispatch_policy == NETISR_DISPATCH_DEFERRED)
return (netisr_queue_src(proto, source, m));

4
sys/net/netisr.h
View File

@ -210,6 +210,10 @@ void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp);
void netisr_register(const struct netisr_handler *nhp);
int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit);
void netisr_unregister(const struct netisr_handler *nhp);
#ifdef VIMAGE
void netisr_register_vnet(const struct netisr_handler *nhp);
void netisr_unregister_vnet(const struct netisr_handler *nhp);
#endif
/*
* Process a packet destined for a protocol, and attempt direct dispatch.

28
sys/net/rtsock.c
View File

@ -191,15 +191,33 @@ SYSCTL_PROC(_net_route, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW,
"maximum routing socket dispatch queue length");
static void
rts_init(void)
vnet_rts_init(void)
{
int tmp;
if (TUNABLE_INT_FETCH("net.route.netisr_maxqlen", &tmp))
rtsock_nh.nh_qlimit = tmp;
netisr_register(&rtsock_nh);
if (IS_DEFAULT_VNET(curvnet)) {
if (TUNABLE_INT_FETCH("net.route.netisr_maxqlen", &tmp))
rtsock_nh.nh_qlimit = tmp;
netisr_register(&rtsock_nh);
}
#ifdef VIMAGE
else
netisr_register_vnet(&rtsock_nh);
#endif
}
SYSINIT(rtsock, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rts_init, 0);
VNET_SYSINIT(vnet_rtsock, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
vnet_rts_init, 0);
#ifdef VIMAGE
static void
vnet_rts_uninit(void)
{
netisr_unregister_vnet(&rtsock_nh);
}
VNET_SYSUNINIT(vnet_rts_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
vnet_rts_uninit, 0);
#endif
static int
raw_input_rts_cb(struct mbuf *m, struct sockproto *proto, struct sockaddr *src,

30
sys/netinet/if_ether.c
View File

@ -143,7 +143,6 @@ SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_log_per_second,
} while (0)
static void arp_init(void);
static void arpintr(struct mbuf *);
static void arptimer(void *);
#ifdef INET
@ -1337,12 +1336,33 @@ arp_iflladdr(void *arg __unused, struct ifnet *ifp)
}
static void
arp_init(void)
vnet_arp_init(void)
{
netisr_register(&arp_nh);
if (IS_DEFAULT_VNET(curvnet))
if (IS_DEFAULT_VNET(curvnet)) {
netisr_register(&arp_nh);
iflladdr_tag = EVENTHANDLER_REGISTER(iflladdr_event,
arp_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
}
#ifdef VIMAGE
else
netisr_register_vnet(&arp_nh);
#endif
}
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
VNET_SYSINIT(vnet_arp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_SECOND,
vnet_arp_init, 0);
#ifdef VIMAGE
/*
* We have to unregister ARP along with IP otherwise we risk doing INADDR_HASH
* lookups after destroying the hash. Ideally this would go on SI_ORDER_3.5.
*/
static void
vnet_arp_destroy(__unused void *arg)
{
netisr_unregister_vnet(&arp_nh);
}
VNET_SYSUNINIT(vnet_arp_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
vnet_arp_destroy, NULL);
#endif

14
sys/netinet/ip_input.c
View File

@ -331,8 +331,15 @@ ip_init(void)
__func__);
/* Skip initialization of globals for non-default instances. */
if (!IS_DEFAULT_VNET(curvnet))
#ifdef VIMAGE
if (!IS_DEFAULT_VNET(curvnet)) {
netisr_register_vnet(&ip_nh);
#ifdef RSS
netisr_register_vnet(&ip_direct_nh);
#endif
return;
}
#endif
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
@ -366,6 +373,11 @@ ip_destroy(void *unused __unused)
{
int error;
#ifdef RSS
netisr_unregister_vnet(&ip_direct_nh);
#endif
netisr_unregister_vnet(&ip_nh);
if ((error = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
printf("%s: WARNING: unable to unregister pfil hook, "
"error %d\n", __func__, error);

14
sys/netinet6/ip6_input.c
View File

@ -217,8 +217,15 @@ ip6_init(void)
V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
/* Skip global initialization stuff for non-default instances. */
if (!IS_DEFAULT_VNET(curvnet))
#ifdef VIMAGE
if (!IS_DEFAULT_VNET(curvnet)) {
netisr_register_vnet(&ip6_nh);
#ifdef RSS
netisr_register_vnet(&ip6_direct_nh);
#endif
return;
}
#endif
pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
@ -310,6 +317,11 @@ ip6_destroy(void *unused __unused)
{
int error;
#ifdef RSS
netisr_unregister_vnet(&ip6_direct_nh);
#endif
netisr_unregister_vnet(&ip6_nh);
if ((error = pfil_head_unregister(&V_inet6_pfil_hook)) != 0)
printf("%s: WARNING: unable to unregister pfil hook, "
"error %d\n", __func__, error);