Support hardware rate limiting (pacing) with TLS offload.

- Add a new send tag type for a send tag that supports both rate
  limiting (packet pacing) and TLS offload (mostly similar to D22669
  but adds a separate structure when allocating the new tag type).

- When allocating a send tag for TLS offload, check to see if the
  connection already has a pacing rate.  If so, allocate a tag that
  supports both rate limiting and TLS offload rather than a plain TLS
  offload tag.

- When setting an initial rate on an existing ifnet KTLS connection,
  set the rate in the TCP control block inp and then reset the TLS
  send tag (via ktls_output_eagain) to reallocate a TLS + ratelimit
  send tag.  This allocates the TLS send tag asynchronously from a
  task queue, so the TLS rate limit tag alloc is always sleepable.

- When modifying a rate on a connection using KTLS, look for a TLS
  send tag.  If the send tag is only a plain TLS send tag, assume we
  failed to allocate a TLS ratelimit tag (either during the
  TCP_TXTLS_ENABLE socket option, or during the send tag reset
  triggered by ktls_output_eagain) and ignore the new rate.  If the
  send tag is a ratelimit TLS send tag, change the rate on the TLS tag
  and leave the inp tag alone.

- Lock the inp lock when setting sb_tls_info for a socket send buffer
  so that the routines in tcp_ratelimit can safely dereference the
  pointer without needing to grab the socket buffer lock.

- Add an IFCAP_TXTLS_RTLMT capability flag and associated
  administrative controls in ifconfig(8).  TLS rate limit tags are
  only allocated if this capability is enabled.  Note that TLS offload
  (whether unlimited or rate limited) always requires IFCAP_TXTLS[46].

Reviewed by:	gallatin, hselasky
Relnotes:	yes
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D26691
This commit is contained in:
John Baldwin 2020-10-29 00:23:16 +00:00
parent ce39811544
commit 521eac97f3
9 changed files with 159 additions and 21 deletions

View File

@ -28,7 +28,7 @@
.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94
.\" $FreeBSD$
.\"
.Dd October 25, 2020
.Dd October 28, 2020
.Dt IFCONFIG 8
.Os
.Sh NAME
@ -561,6 +561,10 @@ It will always disable TLS for
.Xr ip 4
and
.Xr ip6 4 .
.It Cm txtlsrtlmt
Enable use of rate limiting (packet pacing) for TLS offload.
.It Fl txtlsrtlmt
Disable use of rate limiting for TLS offload.
.It Cm nomap
If the driver supports unmapped network buffers,
enable them on the interface.

View File

@ -1345,7 +1345,7 @@ unsetifdescr(const char *val, int value, int s, const struct afswtch *afp)
"\10VLAN_HWCSUM\11TSO4\12TSO6\13LRO\14WOL_UCAST\15WOL_MCAST\16WOL_MAGIC" \
"\17TOE4\20TOE6\21VLAN_HWFILTER\23VLAN_HWTSO\24LINKSTATE\25NETMAP" \
"\26RXCSUM_IPV6\27TXCSUM_IPV6\31TXRTLMT\32HWRXTSTMP\33NOMAP\34TXTLS4\35TXTLS6" \
"\36VXLAN_HWCSUM\37VXLAN_HWTSO"
"\36VXLAN_HWCSUM\37VXLAN_HWTSO\40TXTLS_RTLMT"
/*
* Print the status of the interface. If an address family was
@ -1685,6 +1685,8 @@ static struct cmd basic_cmds[] = {
DEF_CMD("-wol_magic", -IFCAP_WOL_MAGIC, setifcap),
DEF_CMD("txrtlmt", IFCAP_TXRTLMT, setifcap),
DEF_CMD("-txrtlmt", -IFCAP_TXRTLMT, setifcap),
DEF_CMD("txtlsrtlmt", IFCAP_TXTLS_RTLMT, setifcap),
DEF_CMD("-txtlsrtlmt", -IFCAP_TXTLS_RTLMT, setifcap),
DEF_CMD("hwrxtstmp", IFCAP_HWRXTSTMP, setifcap),
DEF_CMD("-hwrxtstmp", -IFCAP_HWRXTSTMP, setifcap),
DEF_CMD("normal", -IFF_LINK0, setifflags),

View File

@ -3349,6 +3349,10 @@ mlx5e_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
ifp->if_capenable ^= IFCAP_TXTLS4;
if (mask & IFCAP_TXTLS6)
ifp->if_capenable ^= IFCAP_TXTLS6;
#ifdef RATELIMIT
if (mask & IFCAP_TXTLS_RTLMT)
ifp->if_capenable ^= IFCAP_TXTLS_RTLMT;
#endif
if (mask & IFCAP_RXCSUM)
ifp->if_capenable ^= IFCAP_RXCSUM;
if (mask & IFCAP_RXCSUM_IPV6)
@ -4320,7 +4324,9 @@ mlx5e_create_ifp(struct mlx5_core_dev *mdev)
ifp->if_capabilities |= IFCAP_HWSTATS | IFCAP_HWRXTSTMP;
ifp->if_capabilities |= IFCAP_NOMAP;
ifp->if_capabilities |= IFCAP_TXTLS4 | IFCAP_TXTLS6;
ifp->if_capabilities |= IFCAP_TXRTLMT;
#ifdef RATELIMIT
ifp->if_capabilities |= IFCAP_TXRTLMT | IFCAP_TXTLS_RTLMT;
#endif
ifp->if_snd_tag_alloc = mlx5e_snd_tag_alloc;
ifp->if_snd_tag_free = mlx5e_snd_tag_free;
ifp->if_snd_tag_modify = mlx5e_snd_tag_modify;

View File

@ -814,12 +814,24 @@ ktls_alloc_snd_tag(struct inpcb *inp, struct ktls_session *tls, bool force,
ifp = nh->nh_ifp;
if_ref(ifp);
params.hdr.type = IF_SND_TAG_TYPE_TLS;
/*
* Allocate a TLS + ratelimit tag if the connection has an
* existing pacing rate.
*/
if (tp->t_pacing_rate != -1 &&
(ifp->if_capenable & IFCAP_TXTLS_RTLMT) != 0) {
params.hdr.type = IF_SND_TAG_TYPE_TLS_RATE_LIMIT;
params.tls_rate_limit.inp = inp;
params.tls_rate_limit.tls = tls;
params.tls_rate_limit.max_rate = tp->t_pacing_rate;
} else {
params.hdr.type = IF_SND_TAG_TYPE_TLS;
params.tls.inp = inp;
params.tls.tls = tls;
}
params.hdr.flowid = inp->inp_flowid;
params.hdr.flowtype = inp->inp_flowtype;
params.hdr.numa_domain = inp->inp_numa_domain;
params.tls.inp = inp;
params.tls.tls = tls;
INP_RUNLOCK(inp);
if (ifp->if_snd_tag_alloc == NULL) {
@ -1034,6 +1046,7 @@ int
ktls_enable_tx(struct socket *so, struct tls_enable *en)
{
struct ktls_session *tls;
struct inpcb *inp;
int error;
if (!ktls_offload_enable)
@ -1086,12 +1099,20 @@ ktls_enable_tx(struct socket *so, struct tls_enable *en)
return (error);
}
/*
* Write lock the INP when setting sb_tls_info so that
* routines in tcp_ratelimit.c can read sb_tls_info while
* holding the INP lock.
*/
inp = so->so_pcb;
INP_WLOCK(inp);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_tls_seqno = be64dec(en->rec_seq);
so->so_snd.sb_tls_info = tls;
if (tls->mode != TCP_TLS_MODE_SW)
so->so_snd.sb_flags |= SB_TLS_IFNET;
SOCKBUF_UNLOCK(&so->so_snd);
INP_WUNLOCK(inp);
sbunlock(&so->so_snd);
counter_u64_add(ktls_offload_total, 1);
@ -1344,6 +1365,42 @@ ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls)
mtx_pool_unlock(mtxpool_sleep, tls);
return (ENOBUFS);
}
#ifdef RATELIMIT
int
ktls_modify_txrtlmt(struct ktls_session *tls, uint64_t max_pacing_rate)
{
union if_snd_tag_modify_params params = {
.rate_limit.max_rate = max_pacing_rate,
.rate_limit.flags = M_NOWAIT,
};
struct m_snd_tag *mst;
struct ifnet *ifp;
int error;
/* Can't get to the inp, but it should be locked. */
/* INP_LOCK_ASSERT(inp); */
MPASS(tls->mode == TCP_TLS_MODE_IFNET);
if (tls->snd_tag == NULL) {
/*
* Resetting send tag, ignore this change. The
* pending reset may or may not see this updated rate
* in the tcpcb. If it doesn't, we will just lose
* this rate change.
*/
return (0);
}
MPASS(tls->snd_tag != NULL);
MPASS(tls->snd_tag->type == IF_SND_TAG_TYPE_TLS_RATE_LIMIT);
mst = tls->snd_tag;
ifp = mst->ifp;
return (ifp->if_snd_tag_modify(mst, &params));
}
#endif
#endif
void

View File

@ -250,6 +250,7 @@ struct if_data {
#define IFCAP_TXTLS6 0x10000000 /* can do TLS encryption and segmentation for TCP6 */
#define IFCAP_VXLAN_HWCSUM 0x20000000 /* can do IFCAN_HWCSUM on VXLANs */
#define IFCAP_VXLAN_HWTSO 0x40000000 /* can do IFCAP_TSO on VXLANs */
#define IFCAP_TXTLS_RTLMT 0x80000000 /* can do TLS with rate limiting */
#define IFCAP_HWCSUM_IPV6 (IFCAP_RXCSUM_IPV6 | IFCAP_TXCSUM_IPV6)

View File

@ -191,7 +191,8 @@ struct m_snd_tag;
#define IF_SND_TAG_TYPE_RATE_LIMIT 0
#define IF_SND_TAG_TYPE_UNLIMITED 1
#define IF_SND_TAG_TYPE_TLS 2
#define IF_SND_TAG_TYPE_MAX 3
#define IF_SND_TAG_TYPE_TLS_RATE_LIMIT 3
#define IF_SND_TAG_TYPE_MAX 4
struct if_snd_tag_alloc_header {
uint32_t type; /* send tag type, see IF_SND_TAG_XXX */
@ -213,6 +214,13 @@ struct if_snd_tag_alloc_tls {
const struct ktls_session *tls;
};
struct if_snd_tag_alloc_tls_rate_limit {
struct if_snd_tag_alloc_header hdr;
struct inpcb *inp;
const struct ktls_session *tls;
uint64_t max_rate; /* in bytes/s */
};
struct if_snd_tag_rate_limit_params {
uint64_t max_rate; /* in bytes/s */
uint32_t queue_level; /* 0 (empty) .. 65535 (full) */
@ -226,16 +234,19 @@ union if_snd_tag_alloc_params {
struct if_snd_tag_alloc_rate_limit rate_limit;
struct if_snd_tag_alloc_rate_limit unlimited;
struct if_snd_tag_alloc_tls tls;
struct if_snd_tag_alloc_tls_rate_limit tls_rate_limit;
};
union if_snd_tag_modify_params {
struct if_snd_tag_rate_limit_params rate_limit;
struct if_snd_tag_rate_limit_params unlimited;
struct if_snd_tag_rate_limit_params tls_rate_limit;
};
union if_snd_tag_query_params {
struct if_snd_tag_rate_limit_params rate_limit;
struct if_snd_tag_rate_limit_params unlimited;
struct if_snd_tag_rate_limit_params tls_rate_limit;
};
/* Query return flags */

View File

@ -1782,10 +1782,10 @@ vlan_capabilities(struct ifvlan *ifv)
* this ever changes, then a new IFCAP_VLAN_TXTLS can be
* defined.
*/
if (p->if_capabilities & IFCAP_TXTLS)
cap |= p->if_capabilities & IFCAP_TXTLS;
if (p->if_capenable & IFCAP_TXTLS)
ena |= mena & IFCAP_TXTLS;
if (p->if_capabilities & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT))
cap |= p->if_capabilities & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT);
if (p->if_capenable & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT))
ena |= mena & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT);
ifp->if_capabilities = cap;
ifp->if_capenable = ena;

View File

@ -1219,6 +1219,9 @@ tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
uint64_t bytes_per_sec, int flags, int *error)
{
const struct tcp_hwrate_limit_table *rte;
#ifdef KERN_TLS
struct ktls_session *tls;
#endif
INP_WLOCK_ASSERT(tp->t_inpcb);
@ -1233,17 +1236,30 @@ tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
return (NULL);
}
#ifdef KERN_TLS
tls = NULL;
if (tp->t_inpcb->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
/*
* We currently can't do both TLS and hardware
* pacing
*/
if (error)
*error = EINVAL;
return (NULL);
tls = tp->t_inpcb->inp_socket->so_snd.sb_tls_info;
if ((ifp->if_capenable & IFCAP_TXTLS_RTLMT) == 0 ||
tls->mode != TCP_TLS_MODE_IFNET) {
if (error)
*error = ENODEV;
return (NULL);
}
}
#endif
rte = rt_setup_rate(tp->t_inpcb, ifp, bytes_per_sec, flags, error);
#ifdef KERN_TLS
if (rte != NULL && tls != NULL && tls->snd_tag != NULL) {
/*
* Fake a route change error to reset the TLS
* send tag. This will convert the existing
* tag to a TLS ratelimit tag.
*/
MPASS(tls->snd_tag->type == IF_SND_TAG_TYPE_TLS);
ktls_output_eagain(tp->t_inpcb, tls);
}
#endif
} else {
/*
* We are modifying a rate, wrong interface?
@ -1264,13 +1280,39 @@ tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
{
const struct tcp_hwrate_limit_table *nrte;
const struct tcp_rate_set *rs;
#ifdef KERN_TLS
struct ktls_session *tls = NULL;
#endif
int is_indirect = 0;
int err;
INP_WLOCK_ASSERT(tp->t_inpcb);
if ((tp->t_inpcb->inp_snd_tag == NULL) ||
(crte == NULL)) {
if (crte == NULL) {
/* Wrong interface */
if (error)
*error = EINVAL;
return (NULL);
}
#ifdef KERN_TLS
if (tp->t_inpcb->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
tls = tp->t_inpcb->inp_socket->so_snd.sb_tls_info;
MPASS(tls->mode == TCP_TLS_MODE_IFNET);
if (tls->snd_tag != NULL &&
tls->snd_tag->type != IF_SND_TAG_TYPE_TLS_RATE_LIMIT) {
/*
* NIC probably doesn't support ratelimit TLS
* tags if it didn't allocate one when an
* existing rate was present, so ignore.
*/
if (error)
*error = EOPNOTSUPP;
return (NULL);
}
}
#endif
if (tp->t_inpcb->inp_snd_tag == NULL) {
/* Wrong interface */
if (error)
*error = EINVAL;
@ -1327,7 +1369,12 @@ tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
return (NULL);
}
/* Change rates to our new entry */
err = in_pcbmodify_txrtlmt(tp->t_inpcb, nrte->rate);
#ifdef KERN_TLS
if (tls != NULL)
err = ktls_modify_txrtlmt(tls, nrte->rate);
else
#endif
err = in_pcbmodify_txrtlmt(tp->t_inpcb, nrte->rate);
if (err) {
if (error)
*error = err;
@ -1365,6 +1412,13 @@ tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte, struct tcpcb *tp)
rs_defer_destroy(rs);
mtx_unlock(&rs_mtx);
}
/*
* XXX: If this connection is using ifnet TLS, should we
* switch it to using an unlimited rate, or perhaps use
* ktls_output_eagain() to reset the send tag to a plain
* TLS tag?
*/
in_pcbdetach_txrtlmt(tp->t_inpcb);
}

View File

@ -222,6 +222,9 @@ int ktls_get_rx_mode(struct socket *so);
int ktls_set_tx_mode(struct socket *so, int mode);
int ktls_get_tx_mode(struct socket *so);
int ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls);
#ifdef RATELIMIT
int ktls_modify_txrtlmt(struct ktls_session *tls, uint64_t max_pacing_rate);
#endif
static inline struct ktls_session *
ktls_hold(struct ktls_session *tls)