Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556155715581559156015611562156315641565156615671568156915701571157215731574157515761577157815791580158115821583158415851586158715881589159015911592159315941595159615971598159916001601160216031604160516061607160816091610161116121613161416151616161716181619162016211622162316241625162616271628162916301631163216331634163516361637163816391640164116421643164416451646164716481649165016511652165316541655165616571658165916601661166216631664166516661667166816691670167116721673167416751676167716781679168016811682168316841685168616871688168916901691169216931694169516961697169816991700170117021703170417051706170717081709171017111712171317141715171617171718171917201721172217231724172517261727172817291730173117321733173417351736173717381739174017411742174317441745174617471748174917501751175217531754175517561757175817591760176117621763176417651766176717681769177017711772177317741775177617771778177917801781178217831784178517861787178817891790179117921793179417951796179717981799180018011802180318041805180618071808180918101811181218131814181518161817181818191820182118221823182418251826182718281829183018311832183318341835183618371838183918401841184218431844184518461847184818491850185118521853185418551856185718581859186018611862186318641865186618671868186918701871187218731874187518761877187818791880188118821883188418851886188718881889189018911892189318941895189618971898189919001901190219031904190519061907190819091910191119121913191419151916// SPDX-License-Identifier: GPL-2.0-only/* Copyright (C) 2009 Red Hat, Inc. * Author: Michael S. Tsirkin <mst@redhat.com> * * virtio-net server in host kernel. */
#include <linux/compat.h>#include <linux/eventfd.h>#include <linux/vhost.h>#include <linux/virtio_net.h>#include <linux/miscdevice.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/mutex.h>#include <linux/workqueue.h>#include <linux/file.h>#include <linux/slab.h>#include <linux/sched/clock.h>#include <linux/sched/signal.h>#include <linux/vmalloc.h>
#include <linux/net.h>#include <linux/if_packet.h>#include <linux/if_arp.h>#include <linux/if_tun.h>#include <linux/if_macvlan.h>#include <linux/if_tap.h>#include <linux/if_vlan.h>#include <linux/skb_array.h>#include <linux/skbuff.h>
#include <net/sock.h>#include <net/xdp.h>
#include "vhost.h"
static int experimental_zcopytx = 0;module_param(experimental_zcopytx, int, 0444);MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" " 1 -Enable; 0 - Disable");
/* Max number of bytes transferred before requeueing the job. * Using this limit prevents one virtqueue from starving others. */#define VHOST_NET_WEIGHT 0x80000
/* Max number of packets transferred before requeueing the job. * Using this limit prevents one virtqueue from starving others with small * pkts. */#define VHOST_NET_PKT_WEIGHT 256
/* MAX number of TX used buffers for outstanding zerocopy */#define VHOST_MAX_PEND 128#define VHOST_GOODCOPY_LEN 256
/* * For transmit, used buffer len is unused; we override it to track buffer * status internally; used for zerocopy tx only. *//* Lower device DMA failed */#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)/* Lower device DMA done */#define VHOST_DMA_DONE_LEN ((__force __virtio32)2)/* Lower device DMA in progress */#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)/* Buffer unused */#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
static const int vhost_net_bits[] = { VHOST_FEATURES, VHOST_NET_F_VIRTIO_NET_HDR, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_F_ACCESS_PLATFORM, VIRTIO_F_RING_RESET, VIRTIO_F_IN_ORDER, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO};
enum { VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)};
enum { VHOST_NET_VQ_RX = 0, VHOST_NET_VQ_TX = 1, VHOST_NET_VQ_MAX = 2,};
struct vhost_net_ubuf_ref { /* refcount follows semantics similar to kref: * 0: object is released * 1: no outstanding ubufs * >1: outstanding ubufs */ atomic_t refcount; wait_queue_head_t wait; struct vhost_virtqueue *vq; struct rcu_head rcu;};
#define VHOST_NET_BATCH 64struct vhost_net_buf { void **queue; int tail; int head;};
struct vhost_net_virtqueue { struct vhost_virtqueue vq; size_t vhost_hlen; size_t sock_hlen; /* vhost zerocopy support fields below: */ /* last used idx for outstanding DMA zerocopy buffers */ int upend_idx; /* For TX, first used idx for DMA done zerocopy buffers * For RX, number of batched heads */ int done_idx; /* Number of XDP frames batched */ int batched_xdp; /* an array of userspace buffers info */ struct ubuf_info_msgzc *ubuf_info; /* Reference counting for outstanding ubufs. * Protected by vq mutex. Writers must also take device mutex. */ struct vhost_net_ubuf_ref *ubufs; struct ptr_ring *rx_ring; struct vhost_net_buf rxq; /* Batched XDP buffs */ struct xdp_buff *xdp;};
struct vhost_net { struct vhost_dev dev; struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX]; struct vhost_poll poll[VHOST_NET_VQ_MAX]; /* Number of TX recently submitted. * Protected by tx vq lock. */ unsigned tx_packets; /* Number of times zerocopy TX recently failed. * Protected by tx vq lock. */ unsigned tx_zcopy_err; /* Flush in progress. Protected by tx vq lock. */ bool tx_flush; /* Private page frag cache */ struct page_frag_cache pf_cache;};
static unsigned vhost_net_zcopy_mask __read_mostly;
static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq){ if (rxq->tail != rxq->head) return rxq->queue[rxq->head]; else return NULL;}
static int vhost_net_buf_get_size(struct vhost_net_buf *rxq){ return rxq->tail - rxq->head;}
static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq){ return rxq->tail == rxq->head;}
static void *vhost_net_buf_consume(struct vhost_net_buf *rxq){ void *ret = vhost_net_buf_get_ptr(rxq); ++rxq->head; return ret;}
static int vhost_net_buf_produce(struct sock *sk, struct vhost_net_virtqueue *nvq){ struct file *file = sk->sk_socket->file; struct vhost_net_buf *rxq = &nvq->rxq;
rxq->head = 0; spin_lock(&nvq->rx_ring->consumer_lock); rxq->tail = __ptr_ring_consume_batched(nvq->rx_ring, rxq->queue, VHOST_NET_BATCH);
if (rxq->tail) tun_wake_queue(file, rxq->tail);
spin_unlock(&nvq->rx_ring->consumer_lock); return rxq->tail;}
static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq){ struct vhost_net_buf *rxq = &nvq->rxq;
if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) { ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head, vhost_net_buf_get_size(rxq), tun_ptr_free); rxq->head = rxq->tail = 0; }}
static int vhost_net_buf_peek_len(void *ptr){ if (tun_is_xdp_frame(ptr)) { struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
return xdpf->len; }
return __skb_array_len_with_tag(ptr);}
static int vhost_net_buf_peek(struct sock *sk, struct vhost_net_virtqueue *nvq){ struct vhost_net_buf *rxq = &nvq->rxq;
if (!vhost_net_buf_is_empty(rxq)) goto out;
if (!vhost_net_buf_produce(sk, nvq)) return 0;
out: return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq));}
static void vhost_net_buf_init(struct vhost_net_buf *rxq){ rxq->head = rxq->tail = 0;}
static void vhost_net_enable_zcopy(int vq){ vhost_net_zcopy_mask |= 0x1 << vq;}
static struct vhost_net_ubuf_ref *vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy){ struct vhost_net_ubuf_ref *ubufs; /* No zero copy backend? Nothing to count. */ if (!zcopy) return NULL; ubufs = kmalloc_obj(*ubufs); if (!ubufs) return ERR_PTR(-ENOMEM); atomic_set(&ubufs->refcount, 1); init_waitqueue_head(&ubufs->wait); ubufs->vq = vq; return ubufs;}
static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs){ int r;
rcu_read_lock(); r = atomic_sub_return(1, &ubufs->refcount); if (unlikely(!r)) wake_up(&ubufs->wait); rcu_read_unlock(); return r;}
static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs){ vhost_net_ubuf_put(ubufs); wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));}
static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs){ vhost_net_ubuf_put_and_wait(ubufs); kfree_rcu(ubufs, rcu);}
static void vhost_net_clear_ubuf_info(struct vhost_net *n){ int i;
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { kfree(n->vqs[i].ubuf_info); n->vqs[i].ubuf_info = NULL; }}
static int vhost_net_set_ubuf_info(struct vhost_net *n){ bool zcopy; int i;
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { zcopy = vhost_net_zcopy_mask & (0x1 << i); if (!zcopy) continue; n->vqs[i].ubuf_info = kmalloc_objs(*n->vqs[i].ubuf_info, UIO_MAXIOV); if (!n->vqs[i].ubuf_info) goto err; } return 0;
err: vhost_net_clear_ubuf_info(n); return -ENOMEM;}
static void vhost_net_vq_reset(struct vhost_net *n){ int i;
vhost_net_clear_ubuf_info(n);
for (i = 0; i < VHOST_NET_VQ_MAX; i++) { n->vqs[i].done_idx = 0; n->vqs[i].upend_idx = 0; n->vqs[i].ubufs = NULL; n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; vhost_net_buf_init(&n->vqs[i].rxq); }
}
static void vhost_net_tx_packet(struct vhost_net *net){ ++net->tx_packets; if (net->tx_packets < 1024) return; net->tx_packets = 0; net->tx_zcopy_err = 0;}
static void vhost_net_tx_err(struct vhost_net *net){ ++net->tx_zcopy_err;}
static bool vhost_net_tx_select_zcopy(struct vhost_net *net){ /* TX flush waits for outstanding DMAs to be done. * Don't start new DMAs. */ return !net->tx_flush && net->tx_packets / 64 >= net->tx_zcopy_err;}
static bool vhost_sock_zcopy(struct socket *sock){ return unlikely(experimental_zcopytx) && sock_flag(sock->sk, SOCK_ZEROCOPY);}
static bool vhost_sock_xdp(struct socket *sock){ return sock_flag(sock->sk, SOCK_XDP);}
/* In case of DMA done not in order in lower device driver for some reason. * upend_idx is used to track end of used idx, done_idx is used to track head * of used idx. Once lower device DMA done contiguously, we will signal KVM * guest used idx. */static void vhost_zerocopy_signal_used(struct vhost_net *net, struct vhost_virtqueue *vq){ struct vhost_net_virtqueue *nvq = container_of(vq, struct vhost_net_virtqueue, vq); int i, add; int j = 0;
for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) { if (vq->heads[i].len == VHOST_DMA_FAILED_LEN) vhost_net_tx_err(net); if (VHOST_DMA_IS_DONE(vq->heads[i].len)) { vq->heads[i].len = VHOST_DMA_CLEAR_LEN; ++j; } else break; } while (j) { add = min(UIO_MAXIOV - nvq->done_idx, j); vhost_add_used_and_signal_n(vq->dev, vq, &vq->heads[nvq->done_idx], NULL, add); nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV; j -= add; }}
static void vhost_zerocopy_complete(struct sk_buff *skb, struct ubuf_info *ubuf_base, bool success){ struct ubuf_info_msgzc *ubuf; struct vhost_net_ubuf_ref *ubufs; struct vhost_virtqueue *vq; int cnt;
/* Only the final cloned skb reference completes the vhost descriptor. */ if (!refcount_dec_and_test(&ubuf_base->refcnt)) return;
ubuf = uarg_to_msgzc(ubuf_base); ubufs = ubuf->ctx; vq = ubufs->vq;
rcu_read_lock_bh(); /* set len to mark this desc buffers done DMA */ vq->heads[ubuf->desc].len = success ? VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN; cnt = vhost_net_ubuf_put(ubufs);
/* * Trigger polling thread if guest stopped submitting new buffers: * in this case, the refcount after decrement will eventually reach 1. * We also trigger polling periodically after each 16 packets * (the value 16 here is more or less arbitrary, it's tuned to trigger * less than 10% of times). */ if (cnt <= 1 || !(cnt % 16)) vhost_poll_queue(&vq->poll);
rcu_read_unlock_bh();}
static const struct ubuf_info_ops vhost_ubuf_ops = { .complete = vhost_zerocopy_complete,};
static inline unsigned long busy_clock(void){ return local_clock() >> 10;}
static bool vhost_can_busy_poll(unsigned long endtime){ return likely(!need_resched() && !time_after(busy_clock(), endtime) && !signal_pending(current));}
static void vhost_net_disable_vq(struct vhost_net *n, struct vhost_virtqueue *vq){ struct vhost_net_virtqueue *nvq = container_of(vq, struct vhost_net_virtqueue, vq); struct vhost_poll *poll = n->poll + (nvq - n->vqs); if (!vhost_vq_get_backend(vq)) return; vhost_poll_stop(poll);}
static int vhost_net_enable_vq(struct vhost_net *n, struct vhost_virtqueue *vq){ struct vhost_net_virtqueue *nvq = container_of(vq, struct vhost_net_virtqueue, vq); struct vhost_poll *poll = n->poll + (nvq - n->vqs); struct socket *sock;
sock = vhost_vq_get_backend(vq); if (!sock) return 0;
return vhost_poll_start(poll, sock->file);}
static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq, unsigned int count){ struct vhost_virtqueue *vq = &nvq->vq; struct vhost_dev *dev = vq->dev;
if (!nvq->done_idx) return;
vhost_add_used_and_signal_n(dev, vq, vq->heads, vq->nheads, count); nvq->done_idx = 0;}
static void vhost_tx_batch(struct vhost_net *net, struct vhost_net_virtqueue *nvq, struct socket *sock, struct msghdr *msghdr){ struct vhost_virtqueue *vq = &nvq->vq; bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); struct tun_msg_ctl ctl = { .type = TUN_MSG_PTR, .num = nvq->batched_xdp, .ptr = nvq->xdp, }; int i, err;
if (in_order) { vq->heads[0].len = 0; vq->nheads[0] = nvq->done_idx; }
if (nvq->batched_xdp == 0) goto signal_used;
msghdr->msg_control = &ctl; msghdr->msg_controllen = sizeof(ctl); err = sock->ops->sendmsg(sock, msghdr, 0); if (unlikely(err < 0)) { vq_err(&nvq->vq, "Fail to batch sending packets\n");
/* free pages owned by XDP; since this is an unlikely error path, * keep it simple and avoid more complex bulk update for the * used pages */ for (i = 0; i < nvq->batched_xdp; ++i) put_page(virt_to_head_page(nvq->xdp[i].data)); nvq->batched_xdp = 0; nvq->done_idx = 0; return; }
signal_used: vhost_net_signal_used(nvq, in_order ? 1 : nvq->done_idx); nvq->batched_xdp = 0;}
static int sock_has_rx_data(struct socket *sock){ if (unlikely(!sock)) return 0;
if (sock->ops->peek_len) return sock->ops->peek_len(sock);
return skb_queue_empty(&sock->sk->sk_receive_queue);}
static void vhost_net_busy_poll_try_queue(struct vhost_net *net, struct vhost_virtqueue *vq){ if (!vhost_vq_avail_empty(&net->dev, vq)) { vhost_poll_queue(&vq->poll); } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { vhost_disable_notify(&net->dev, vq); vhost_poll_queue(&vq->poll); }}
static void vhost_net_busy_poll(struct vhost_net *net, struct vhost_virtqueue *rvq, struct vhost_virtqueue *tvq, bool *busyloop_intr, bool poll_rx){ unsigned long busyloop_timeout; unsigned long endtime; struct socket *sock; struct vhost_virtqueue *vq = poll_rx ? tvq : rvq;
/* Try to hold the vq mutex of the paired virtqueue. We can't * use mutex_lock() here since we could not guarantee a * consistenet lock ordering. */ if (!mutex_trylock(&vq->mutex)) return;
vhost_disable_notify(&net->dev, vq); sock = vhost_vq_get_backend(rvq);
busyloop_timeout = poll_rx ? rvq->busyloop_timeout: tvq->busyloop_timeout;
migrate_disable(); endtime = busy_clock() + busyloop_timeout;
while (vhost_can_busy_poll(endtime)) { if (vhost_vq_has_work(vq)) { *busyloop_intr = true; break; }
if ((sock_has_rx_data(sock) && !vhost_vq_avail_empty(&net->dev, rvq)) || !vhost_vq_avail_empty(&net->dev, tvq)) break;
cpu_relax(); }
migrate_enable();
if (poll_rx || sock_has_rx_data(sock)) vhost_net_busy_poll_try_queue(net, vq); else if (!poll_rx) /* On tx here, sock has no rx data. */ vhost_enable_notify(&net->dev, rvq);
mutex_unlock(&vq->mutex);}
static int vhost_net_tx_get_vq_desc(struct vhost_net *net, struct vhost_net_virtqueue *tnvq, unsigned int *out_num, unsigned int *in_num, struct msghdr *msghdr, bool *busyloop_intr, unsigned int *ndesc){ struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX]; struct vhost_virtqueue *rvq = &rnvq->vq; struct vhost_virtqueue *tvq = &tnvq->vq;
int r = vhost_get_vq_desc_n(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), out_num, in_num, NULL, NULL, ndesc);
if (r == tvq->num && tvq->busyloop_timeout) { /* Flush batched packets first */ if (!vhost_sock_zcopy(vhost_vq_get_backend(tvq))) vhost_tx_batch(net, tnvq, vhost_vq_get_backend(tvq), msghdr);
vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false);
r = vhost_get_vq_desc_n(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), out_num, in_num, NULL, NULL, ndesc); }
return r;}
static bool vhost_exceeds_maxpend(struct vhost_net *net){ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq;
return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV > min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);}
static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter, size_t hdr_size, int out){ /* Skip header. TODO: support TSO. */ size_t len = iov_length(vq->iov, out);
iov_iter_init(iter, ITER_SOURCE, vq->iov, out, len); iov_iter_advance(iter, hdr_size);
return iov_iter_count(iter);}
static int get_tx_bufs(struct vhost_net *net, struct vhost_net_virtqueue *nvq, struct msghdr *msg, unsigned int *out, unsigned int *in, size_t *len, bool *busyloop_intr, unsigned int *ndesc){ struct vhost_virtqueue *vq = &nvq->vq; int ret;
ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr, ndesc);
if (ret < 0 || ret == vq->num) return ret;
if (*in) { vq_err(vq, "Unexpected descriptor format for TX: out %d, int %d\n", *out, *in); return -EFAULT; }
/* Sanity check */ *len = init_iov_iter(vq, &msg->msg_iter, nvq->vhost_hlen, *out); if (*len == 0) { vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n", *len, nvq->vhost_hlen); return -EFAULT; }
return ret;}
static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len){ return total_len < VHOST_NET_WEIGHT && !vhost_vq_avail_empty(vq->dev, vq);}
#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq, struct iov_iter *from){ struct vhost_virtqueue *vq = &nvq->vq; struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); struct socket *sock = vhost_vq_get_backend(vq); struct virtio_net_hdr *gso; struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp]; size_t len = iov_iter_count(from); int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0; int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); int pad = SKB_DATA_ALIGN(VHOST_NET_RX_PAD + headroom + nvq->sock_hlen); int sock_hlen = nvq->sock_hlen; void *buf; int copied; int ret;
if (unlikely(len < nvq->sock_hlen)) return -EFAULT;
if (SKB_DATA_ALIGN(len + pad) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE) return -ENOSPC;
buflen += SKB_DATA_ALIGN(len + pad); buf = page_frag_alloc_align(&net->pf_cache, buflen, GFP_KERNEL, SMP_CACHE_BYTES); if (unlikely(!buf)) return -ENOMEM;
copied = copy_from_iter(buf + pad - sock_hlen, len, from); if (copied != len) { ret = -EFAULT; goto err; }
if (!sock_hlen) { memset(buf, 0, pad); gso = buf; } else { gso = buf + pad - sock_hlen; }
if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && vhost16_to_cpu(vq, gso->csum_start) + vhost16_to_cpu(vq, gso->csum_offset) + 2 > vhost16_to_cpu(vq, gso->hdr_len)) { gso->hdr_len = cpu_to_vhost16(vq, vhost16_to_cpu(vq, gso->csum_start) + vhost16_to_cpu(vq, gso->csum_offset) + 2);
if (vhost16_to_cpu(vq, gso->hdr_len) > len) { ret = -EINVAL; goto err; } }
/* pad contains sock_hlen */ memcpy(buf, buf + pad - sock_hlen, sock_hlen);
xdp_init_buff(xdp, buflen, NULL); xdp_prepare_buff(xdp, buf, pad, len - sock_hlen, true);
++nvq->batched_xdp;
return 0;
err: page_frag_free(buf); return ret;}
static void handle_tx_copy(struct vhost_net *net, struct socket *sock){ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq; unsigned out, in; int head; struct msghdr msg = { .msg_name = NULL, .msg_namelen = 0, .msg_control = NULL, .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, }; size_t len, total_len = 0; int err; int sent_pkts = 0; bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX); bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); unsigned int ndesc = 0;
do { bool busyloop_intr = false;
if (nvq->done_idx == VHOST_NET_BATCH) vhost_tx_batch(net, nvq, sock, &msg);
head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, &busyloop_intr, &ndesc); /* On error, stop handling until the next kick. */ if (unlikely(head < 0)) break; /* Nothing new? Wait for eventfd to tell us they refilled. */ if (head == vq->num) { /* Flush batched packets to handle pending RX * work (if busyloop_intr is set) and to avoid * unnecessary virtqueue kicks. */ vhost_tx_batch(net, nvq, sock, &msg); if (unlikely(busyloop_intr)) { vhost_poll_queue(&vq->poll); } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { vhost_disable_notify(&net->dev, vq); continue; } break; }
total_len += len;
/* For simplicity, TX batching is only enabled if * sndbuf is unlimited. */ if (sock_can_batch) { err = vhost_net_build_xdp(nvq, &msg.msg_iter); if (!err) { goto done; } else if (unlikely(err != -ENOSPC)) { vhost_tx_batch(net, nvq, sock, &msg); vhost_discard_vq_desc(vq, 1, ndesc); vhost_net_enable_vq(net, vq); break; }
if (nvq->batched_xdp) { /* We can't build XDP buff, go for single * packet path but let's flush batched * packets. */ vhost_tx_batch(net, nvq, sock, &msg); } msg.msg_control = NULL; } else { if (tx_can_batch(vq, total_len)) msg.msg_flags |= MSG_MORE; else msg.msg_flags &= ~MSG_MORE; }
err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { vhost_discard_vq_desc(vq, 1, ndesc); vhost_net_enable_vq(net, vq); break; } pr_debug("Fail to send packet: err %d", err); } else if (unlikely(err != len)) pr_debug("Truncated TX packet: len %d != %zd\n", err, len);done: if (in_order) { vq->heads[0].id = cpu_to_vhost32(vq, head); } else { vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head); vq->heads[nvq->done_idx].len = 0; } ++nvq->done_idx; } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));
vhost_tx_batch(net, nvq, sock, &msg);}
static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock){ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq; unsigned out, in; int head; struct msghdr msg = { .msg_name = NULL, .msg_namelen = 0, .msg_control = NULL, .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, }; struct tun_msg_ctl ctl; size_t len, total_len = 0; int err; struct vhost_net_ubuf_ref *ubufs; struct ubuf_info_msgzc *ubuf; unsigned int ndesc = 0; bool zcopy_used; int sent_pkts = 0;
do { bool busyloop_intr;
/* Release DMAs done buffers first */ vhost_zerocopy_signal_used(net, vq);
busyloop_intr = false; head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, &busyloop_intr, &ndesc); /* On error, stop handling until the next kick. */ if (unlikely(head < 0)) break; /* Nothing new? Wait for eventfd to tell us they refilled. */ if (head == vq->num) { if (unlikely(busyloop_intr)) { vhost_poll_queue(&vq->poll); } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { vhost_disable_notify(&net->dev, vq); continue; } break; }
zcopy_used = len >= VHOST_GOODCOPY_LEN && !vhost_exceeds_maxpend(net) && vhost_net_tx_select_zcopy(net);
/* use msg_control to pass vhost zerocopy ubuf info to skb */ if (zcopy_used) { ubuf = nvq->ubuf_info + nvq->upend_idx; vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head); vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; ubuf->ctx = nvq->ubufs; ubuf->desc = nvq->upend_idx; ubuf->ubuf.ops = &vhost_ubuf_ops; ubuf->ubuf.flags = SKBFL_ZEROCOPY_FRAG; refcount_set(&ubuf->ubuf.refcnt, 1); msg.msg_control = &ctl; ctl.type = TUN_MSG_UBUF; ctl.ptr = &ubuf->ubuf; msg.msg_controllen = sizeof(ctl); ubufs = nvq->ubufs; atomic_inc(&ubufs->refcount); nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; } else { msg.msg_control = NULL; ubufs = NULL; } total_len += len; if (tx_can_batch(vq, total_len) && likely(!vhost_exceeds_maxpend(net))) { msg.msg_flags |= MSG_MORE; } else { msg.msg_flags &= ~MSG_MORE; }
err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { bool retry = err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS;
if (zcopy_used) { if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) vhost_net_ubuf_put(ubufs); if (retry) nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; else vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN; } if (retry) { vhost_discard_vq_desc(vq, 1, ndesc); vhost_net_enable_vq(net, vq); break; } pr_debug("Fail to send packet: err %d", err); } else if (unlikely(err != len)) pr_debug("Truncated TX packet: " " len %d != %zd\n", err, len); if (!zcopy_used) vhost_add_used_and_signal(&net->dev, vq, head, 0); else vhost_zerocopy_signal_used(net, vq); vhost_net_tx_packet(net); } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));}
/* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */static void handle_tx(struct vhost_net *net){ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq; struct socket *sock;
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX); sock = vhost_vq_get_backend(vq); if (!sock) goto out;
if (!vq_meta_prefetch(vq)) goto out;
vhost_disable_notify(&net->dev, vq); vhost_net_disable_vq(net, vq);
if (vhost_sock_zcopy(sock)) handle_tx_zerocopy(net, sock); else handle_tx_copy(net, sock);
out: mutex_unlock(&vq->mutex);}
static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk){ struct sk_buff *head; int len = 0; unsigned long flags;
if (rvq->rx_ring) return vhost_net_buf_peek(sk, rvq);
spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); head = skb_peek(&sk->sk_receive_queue); if (likely(head)) { len = head->len; if (skb_vlan_tag_present(head)) len += VLAN_HLEN; }
spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); return len;}
static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk, bool *busyloop_intr, unsigned int *count){ struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX]; struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *rvq = &rnvq->vq; struct vhost_virtqueue *tvq = &tnvq->vq; int len = peek_head_len(rnvq, sk);
if (!len && rvq->busyloop_timeout) { /* Flush batched heads first */ vhost_net_signal_used(rnvq, *count); *count = 0; /* Both tx vq and rx socket were polled here */ vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true);
len = peek_head_len(rnvq, sk); }
return len;}
/* This is a multi-buffer version of vhost_get_desc, that works if * vq has read descriptors only. * @nvq - the relevant vhost_net virtqueue * @datalen - data length we'll be reading * @iovcount - returned count of io vectors we fill * @log - vhost log * @log_num - log offset * @quota - headcount quota, 1 for big buffer * returns number of buffer heads allocated, negative on error */static int get_rx_bufs(struct vhost_net_virtqueue *nvq, struct vring_used_elem *heads, u16 *nheads, int datalen, unsigned *iovcount, struct vhost_log *log, unsigned *log_num, unsigned int quota, unsigned int *ndesc){ struct vhost_virtqueue *vq = &nvq->vq; bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); unsigned int out, in, desc_num, n = 0; int seg = 0; int headcount = 0; unsigned d; int r, nlogs = 0; /* len is always initialized before use since we are always called with * datalen > 0. */ u32 len;
while (datalen > 0 && headcount < quota) { if (unlikely(seg >= UIO_MAXIOV)) { r = -ENOBUFS; goto err; } r = vhost_get_vq_desc_n(vq, vq->iov + seg, ARRAY_SIZE(vq->iov) - seg, &out, &in, log, log_num, &desc_num); if (unlikely(r < 0)) goto err;
d = r; if (d == vq->num) { r = 0; goto err; } if (unlikely(out || in <= 0)) { vq_err(vq, "unexpected descriptor format for RX: " "out %d, in %d\n", out, in); r = -EINVAL; goto err; } if (unlikely(log)) { nlogs += *log_num; log += *log_num; } len = iov_length(vq->iov + seg, in); if (!in_order) { heads[headcount].id = cpu_to_vhost32(vq, d); heads[headcount].len = cpu_to_vhost32(vq, len); } ++headcount; datalen -= len; seg += in; n += desc_num; }
*iovcount = seg; if (unlikely(log)) *log_num = nlogs;
/* Detect overrun */ if (unlikely(datalen > 0)) { r = UIO_MAXIOV + 1; goto err; }
if (!in_order) heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); else { heads[0].len = cpu_to_vhost32(vq, len + datalen); heads[0].id = cpu_to_vhost32(vq, d); nheads[0] = headcount; }
*ndesc = n;
return headcount;err: vhost_discard_vq_desc(vq, headcount, n); return r;}
/* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */static void handle_rx(struct vhost_net *net){ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX]; struct vhost_virtqueue *vq = &nvq->vq; bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); unsigned int count = 0; unsigned in, log; struct vhost_log *vq_log; struct msghdr msg = { .msg_name = NULL, .msg_namelen = 0, .msg_control = NULL, /* FIXME: get and handle RX aux data. */ .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, }; struct virtio_net_hdr hdr = { .flags = 0, .gso_type = VIRTIO_NET_HDR_GSO_NONE }; size_t total_len = 0; int err, mergeable; s16 headcount; size_t vhost_hlen, sock_hlen; size_t vhost_len, sock_len; bool busyloop_intr = false; bool set_num_buffers; struct socket *sock; struct iov_iter fixup; __virtio16 num_buffers; int recv_pkts = 0; unsigned int ndesc;
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX); sock = vhost_vq_get_backend(vq); if (!sock) goto out;
if (!vq_meta_prefetch(vq)) goto out;
vhost_disable_notify(&net->dev, vq); vhost_net_disable_vq(net, vq);
vhost_hlen = nvq->vhost_hlen; sock_hlen = nvq->sock_hlen;
vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ? vq->log : NULL; mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); set_num_buffers = mergeable || vhost_has_feature(vq, VIRTIO_F_VERSION_1);
do { sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr, &count); if (!sock_len) break; sock_len += sock_hlen; vhost_len = sock_len + vhost_hlen; headcount = get_rx_bufs(nvq, vq->heads + count, vq->nheads + count, vhost_len, &in, vq_log, &log, likely(mergeable) ? UIO_MAXIOV : 1, &ndesc); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) goto out; /* OK, now we need to know about added descriptors. */ if (!headcount) { if (unlikely(busyloop_intr)) { vhost_poll_queue(&vq->poll); } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { /* They have slipped one in as we were * doing that: check again. */ vhost_disable_notify(&net->dev, vq); continue; } /* Nothing new? Wait for eventfd to tell us * they refilled. */ goto out; } busyloop_intr = false; if (nvq->rx_ring) msg.msg_control = vhost_net_buf_consume(&nvq->rxq); /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, 1, 1); err = sock->ops->recvmsg(sock, &msg, 1, MSG_DONTWAIT | MSG_TRUNC); pr_debug("Discarded rx packet: len %zd\n", sock_len); continue; } /* We don't need to be notified again. */ iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, in, vhost_len); fixup = msg.msg_iter; if (unlikely((vhost_hlen))) { /* We will supply the header ourselves * TODO: support TSO. */ iov_iter_advance(&msg.msg_iter, vhost_hlen); } err = sock->ops->recvmsg(sock, &msg, sock_len, MSG_DONTWAIT | MSG_TRUNC); /* Userspace might have consumed the packet meanwhile: * it's not supposed to do this usually, but might be hard * to prevent. Discard data we got (if any) and keep going. */ if (unlikely(err != sock_len)) { pr_debug("Discarded rx packet: " " len %d, expected %zd\n", err, sock_len); vhost_discard_vq_desc(vq, headcount, ndesc); continue; } /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ if (unlikely(vhost_hlen)) { if (copy_to_iter(&hdr, sizeof(hdr), &fixup) != sizeof(hdr)) { vq_err(vq, "Unable to write vnet_hdr " "at addr %p\n", vq->iov->iov_base); goto out; } } else { /* Header came from socket; we'll need to patch * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF */ iov_iter_advance(&fixup, sizeof(hdr)); } /* TODO: Should check and handle checksum. */
num_buffers = cpu_to_vhost16(vq, headcount); if (likely(set_num_buffers) && copy_to_iter(&num_buffers, sizeof num_buffers, &fixup) != sizeof num_buffers) { vq_err(vq, "Failed num_buffers write"); vhost_discard_vq_desc(vq, headcount, ndesc); goto out; } nvq->done_idx += headcount; count += in_order ? 1 : headcount; if (nvq->done_idx > VHOST_NET_BATCH) { vhost_net_signal_used(nvq, count); count = 0; } if (unlikely(vq_log)) vhost_log_write(vq, vq_log, log, vhost_len, vq->iov, in); total_len += vhost_len; } while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len)));
if (unlikely(busyloop_intr)) vhost_poll_queue(&vq->poll); else if (!sock_len) vhost_net_enable_vq(net, vq);out: vhost_net_signal_used(nvq, count); mutex_unlock(&vq->mutex);}
static void handle_tx_kick(struct vhost_work *work){ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, poll.work); struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
handle_tx(net);}
static void handle_rx_kick(struct vhost_work *work){ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, poll.work); struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
handle_rx(net);}
static void handle_tx_net(struct vhost_work *work){ struct vhost_net *net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_TX].work); handle_tx(net);}
static void handle_rx_net(struct vhost_work *work){ struct vhost_net *net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_RX].work); handle_rx(net);}
static int vhost_net_open(struct inode *inode, struct file *f){ struct vhost_net *n; struct vhost_dev *dev; struct vhost_virtqueue **vqs; void **queue; struct xdp_buff *xdp; int i;
n = kvmalloc_obj(*n, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!n) return -ENOMEM; vqs = kmalloc_objs(*vqs, VHOST_NET_VQ_MAX); if (!vqs) { kvfree(n); return -ENOMEM; }
queue = kmalloc_array(VHOST_NET_BATCH, sizeof(void *), GFP_KERNEL); if (!queue) { kfree(vqs); kvfree(n); return -ENOMEM; } n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue;
xdp = kmalloc_objs(*xdp, VHOST_NET_BATCH); if (!xdp) { kfree(vqs); kvfree(n); kfree(queue); return -ENOMEM; } n->vqs[VHOST_NET_VQ_TX].xdp = xdp;
dev = &n->dev; vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq; vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq; n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick; n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick; for (i = 0; i < VHOST_NET_VQ_MAX; i++) { n->vqs[i].ubufs = NULL; n->vqs[i].ubuf_info = NULL; n->vqs[i].upend_idx = 0; n->vqs[i].done_idx = 0; n->vqs[i].batched_xdp = 0; n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; n->vqs[i].rx_ring = NULL; vhost_net_buf_init(&n->vqs[i].rxq); } vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX, UIO_MAXIOV + VHOST_NET_BATCH, VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true, NULL);
vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev, vqs[VHOST_NET_VQ_TX]); vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev, vqs[VHOST_NET_VQ_RX]);
f->private_data = n; page_frag_cache_init(&n->pf_cache);
return 0;}
static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct vhost_virtqueue *vq){ struct socket *sock; struct vhost_net_virtqueue *nvq = container_of(vq, struct vhost_net_virtqueue, vq);
mutex_lock(&vq->mutex); sock = vhost_vq_get_backend(vq); vhost_net_disable_vq(n, vq); vhost_vq_set_backend(vq, NULL); vhost_net_buf_unproduce(nvq); nvq->rx_ring = NULL; mutex_unlock(&vq->mutex); return sock;}
static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, struct socket **rx_sock){ *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq); *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);}
static void vhost_net_flush(struct vhost_net *n){ vhost_dev_flush(&n->dev); if (n->vqs[VHOST_NET_VQ_TX].ubufs) { mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); n->tx_flush = true; mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); /* Wait for all lower device DMAs done. */ vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs); mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); n->tx_flush = false; atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1); mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); }}
static int vhost_net_release(struct inode *inode, struct file *f){ struct vhost_net *n = f->private_data; struct socket *tx_sock; struct socket *rx_sock;
vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_stop(&n->dev); vhost_dev_cleanup(&n->dev, false); vhost_net_vq_reset(n); if (tx_sock) sockfd_put(tx_sock); if (rx_sock) sockfd_put(rx_sock); /* Make sure no callbacks are outstanding */ synchronize_rcu(); /* We do an extra flush before freeing memory, * since jobs can re-queue themselves. */ vhost_net_flush(n); kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue); kfree(n->vqs[VHOST_NET_VQ_TX].xdp); kfree(n->dev.vqs); page_frag_cache_drain(&n->pf_cache); kvfree(n); return 0;}
static struct socket *get_raw_socket(int fd){ int r; struct socket *sock = sockfd_lookup(fd, &r);
if (!sock) return ERR_PTR(-ENOTSOCK);
/* Parameter checking */ if (sock->sk->sk_type != SOCK_RAW) { r = -ESOCKTNOSUPPORT; goto err; }
if (sock->sk->sk_family != AF_PACKET) { r = -EPFNOSUPPORT; goto err; } return sock;err: sockfd_put(sock); return ERR_PTR(r);}
static struct ptr_ring *get_tap_ptr_ring(struct file *file){ struct ptr_ring *ring; ring = tun_get_tx_ring(file); if (!IS_ERR(ring)) goto out; ring = tap_get_ptr_ring(file); if (!IS_ERR(ring)) goto out; ring = NULL;out: return ring;}
static struct socket *get_tap_socket(int fd){ struct file *file = fget(fd); struct socket *sock;
if (!file) return ERR_PTR(-EBADF); sock = tun_get_socket(file); if (!IS_ERR(sock)) return sock; sock = tap_get_socket(file); if (IS_ERR(sock)) fput(file); return sock;}
static struct socket *get_socket(int fd){ struct socket *sock;
/* special case to disable backend */ if (fd == -1) return NULL; sock = get_raw_socket(fd); if (!IS_ERR(sock)) return sock; sock = get_tap_socket(fd); if (!IS_ERR(sock)) return sock; return ERR_PTR(-ENOTSOCK);}
static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd){ struct socket *sock, *oldsock; struct vhost_virtqueue *vq; struct vhost_net_virtqueue *nvq; struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL; int r;
mutex_lock(&n->dev.mutex); r = vhost_dev_check_owner(&n->dev); if (r) goto err;
if (index >= VHOST_NET_VQ_MAX) { r = -ENOBUFS; goto err; } vq = &n->vqs[index].vq; nvq = &n->vqs[index]; mutex_lock(&vq->mutex);
if (fd == -1) vhost_clear_msg(&n->dev);
/* Verify that ring has been setup correctly. */ if (!vhost_vq_access_ok(vq)) { r = -EFAULT; goto err_vq; } sock = get_socket(fd); if (IS_ERR(sock)) { r = PTR_ERR(sock); goto err_vq; }
/* start polling new socket */ oldsock = vhost_vq_get_backend(vq); if (sock != oldsock) { ubufs = vhost_net_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); if (IS_ERR(ubufs)) { r = PTR_ERR(ubufs); goto err_ubufs; }
vhost_net_disable_vq(n, vq); vhost_vq_set_backend(vq, sock); vhost_net_buf_unproduce(nvq); r = vhost_vq_init_access(vq); if (r) goto err_used; r = vhost_net_enable_vq(n, vq); if (r) goto err_used; if (index == VHOST_NET_VQ_RX) { if (sock) nvq->rx_ring = get_tap_ptr_ring(sock->file); else nvq->rx_ring = NULL; }
oldubufs = nvq->ubufs; nvq->ubufs = ubufs;
n->tx_packets = 0; n->tx_zcopy_err = 0; n->tx_flush = false; }
mutex_unlock(&vq->mutex);
if (oldubufs) { vhost_net_ubuf_put_wait_and_free(oldubufs); mutex_lock(&vq->mutex); vhost_zerocopy_signal_used(n, vq); mutex_unlock(&vq->mutex); }
if (oldsock) { vhost_dev_flush(&n->dev); sockfd_put(oldsock); }
mutex_unlock(&n->dev.mutex); return 0;
err_used: vhost_vq_set_backend(vq, oldsock); vhost_net_enable_vq(n, vq); if (ubufs) vhost_net_ubuf_put_wait_and_free(ubufs);err_ubufs: if (sock) sockfd_put(sock);err_vq: mutex_unlock(&vq->mutex);err: mutex_unlock(&n->dev.mutex); return r;}
static long vhost_net_reset_owner(struct vhost_net *n){ struct socket *tx_sock = NULL; struct socket *rx_sock = NULL; long err; struct vhost_iotlb *umem;
mutex_lock(&n->dev.mutex); err = vhost_dev_check_owner(&n->dev); if (err) goto done; umem = vhost_dev_reset_owner_prepare(); if (!umem) { err = -ENOMEM; goto done; } vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_stop(&n->dev); vhost_dev_reset_owner(&n->dev, umem, false); vhost_net_vq_reset(n);done: mutex_unlock(&n->dev.mutex); if (tx_sock) sockfd_put(tx_sock); if (rx_sock) sockfd_put(rx_sock); return err;}
static int vhost_net_set_features(struct vhost_net *n, const u64 *features){ size_t vhost_hlen, sock_hlen, hdr_len; int i;
hdr_len = virtio_features_test_bit(features, VIRTIO_NET_F_MRG_RXBUF) || virtio_features_test_bit(features, VIRTIO_F_VERSION_1) ? sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
if (virtio_features_test_bit(features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO) || virtio_features_test_bit(features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO)) hdr_len = sizeof(struct virtio_net_hdr_v1_hash_tunnel);
if (virtio_features_test_bit(features, VHOST_NET_F_VIRTIO_NET_HDR)) { /* vhost provides vnet_hdr */ vhost_hlen = hdr_len; sock_hlen = 0; } else { /* socket provides vnet_hdr */ vhost_hlen = 0; sock_hlen = hdr_len; } mutex_lock(&n->dev.mutex); if (virtio_features_test_bit(features, VHOST_F_LOG_ALL) && !vhost_log_access_ok(&n->dev)) goto out_unlock;
if (virtio_features_test_bit(features, VIRTIO_F_ACCESS_PLATFORM)) { if (vhost_init_device_iotlb(&n->dev)) goto out_unlock; } else { vhost_clear_device_iotlb(&n->dev); }
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { mutex_lock(&n->vqs[i].vq.mutex); virtio_features_copy(n->vqs[i].vq.acked_features_array, features); n->vqs[i].vhost_hlen = vhost_hlen; n->vqs[i].sock_hlen = sock_hlen; mutex_unlock(&n->vqs[i].vq.mutex); } mutex_unlock(&n->dev.mutex); return 0;
out_unlock: mutex_unlock(&n->dev.mutex); return -EFAULT;}
static long vhost_net_set_owner(struct vhost_net *n){ int r;
mutex_lock(&n->dev.mutex); if (vhost_dev_has_owner(&n->dev)) { r = -EBUSY; goto out; } r = vhost_net_set_ubuf_info(n); if (r) goto out; r = vhost_dev_set_owner(&n->dev); if (r) vhost_net_clear_ubuf_info(n); vhost_net_flush(n);out: mutex_unlock(&n->dev.mutex); return r;}
static long vhost_net_ioctl(struct file *f, unsigned int ioctl, unsigned long arg){ const DEFINE_VHOST_FEATURES_ARRAY(vhost_net_features, vhost_net_bits); u64 all_features[VIRTIO_FEATURES_U64S]; struct vhost_net *n = f->private_data; void __user *argp = (void __user *)arg; u64 __user *featurep = argp; struct vhost_vring_file backend; u64 features, count, copied; int r, i;
switch (ioctl) { case VHOST_NET_SET_BACKEND: if (copy_from_user(&backend, argp, sizeof backend)) return -EFAULT; return vhost_net_set_backend(n, backend.index, backend.fd); case VHOST_GET_FEATURES: features = vhost_net_features[0]; if (copy_to_user(featurep, &features, sizeof features)) return -EFAULT; return 0; case VHOST_SET_FEATURES: if (copy_from_user(&features, featurep, sizeof features)) return -EFAULT; if (features & ~vhost_net_features[0]) return -EOPNOTSUPP;
virtio_features_from_u64(all_features, features); return vhost_net_set_features(n, all_features); case VHOST_GET_FEATURES_ARRAY: if (copy_from_user(&count, featurep, sizeof(count))) return -EFAULT;
/* Copy the net features, up to the user-provided buffer size */ argp += sizeof(u64); copied = min(count, (u64)VIRTIO_FEATURES_U64S); if (copy_to_user(argp, vhost_net_features, copied * sizeof(u64))) return -EFAULT;
/* Zero the trailing space provided by user-space, if any */ if (clear_user(argp + size_mul(copied, sizeof(u64)), size_mul(count - copied, sizeof(u64)))) return -EFAULT; return 0; case VHOST_SET_FEATURES_ARRAY: if (copy_from_user(&count, featurep, sizeof(count))) return -EFAULT;
virtio_features_zero(all_features); argp += sizeof(u64); copied = min(count, (u64)VIRTIO_FEATURES_U64S); if (copy_from_user(all_features, argp, copied * sizeof(u64))) return -EFAULT;
/* * Any feature specified by user-space above * VIRTIO_FEATURES_BITS is not supported by definition. */ for (i = copied; i < count; ++i) { if (copy_from_user(&features, featurep + 1 + i, sizeof(features))) return -EFAULT; if (features) return -EOPNOTSUPP; }
for (i = 0; i < VIRTIO_FEATURES_U64S; i++) if (all_features[i] & ~vhost_net_features[i]) return -EOPNOTSUPP;
return vhost_net_set_features(n, all_features); case VHOST_GET_BACKEND_FEATURES: features = VHOST_NET_BACKEND_FEATURES; if (copy_to_user(featurep, &features, sizeof(features))) return -EFAULT; return 0; case VHOST_SET_BACKEND_FEATURES: if (copy_from_user(&features, featurep, sizeof(features))) return -EFAULT; if (features & ~VHOST_NET_BACKEND_FEATURES) return -EOPNOTSUPP; vhost_set_backend_features(&n->dev, features); return 0; case VHOST_RESET_OWNER: return vhost_net_reset_owner(n); case VHOST_SET_OWNER: return vhost_net_set_owner(n); default: mutex_lock(&n->dev.mutex); r = vhost_dev_ioctl(&n->dev, ioctl, argp); if (r == -ENOIOCTLCMD) r = vhost_vring_ioctl(&n->dev, ioctl, argp); else vhost_net_flush(n); mutex_unlock(&n->dev.mutex); return r; }}
static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to){ struct file *file = iocb->ki_filp; struct vhost_net *n = file->private_data; struct vhost_dev *dev = &n->dev; int noblock = file->f_flags & O_NONBLOCK;
return vhost_chr_read_iter(dev, to, noblock);}
static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb, struct iov_iter *from){ struct file *file = iocb->ki_filp; struct vhost_net *n = file->private_data; struct vhost_dev *dev = &n->dev;
return vhost_chr_write_iter(dev, from);}
static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait){ struct vhost_net *n = file->private_data; struct vhost_dev *dev = &n->dev;
return vhost_chr_poll(file, dev, wait);}
static const struct file_operations vhost_net_fops = { .owner = THIS_MODULE, .release = vhost_net_release, .read_iter = vhost_net_chr_read_iter, .write_iter = vhost_net_chr_write_iter, .poll = vhost_net_chr_poll, .unlocked_ioctl = vhost_net_ioctl, .compat_ioctl = compat_ptr_ioctl, .open = vhost_net_open, .llseek = noop_llseek,};
static struct miscdevice vhost_net_misc = { .minor = VHOST_NET_MINOR, .name = "vhost-net", .fops = &vhost_net_fops,};
static int __init vhost_net_init(void){ if (experimental_zcopytx) vhost_net_enable_zcopy(VHOST_NET_VQ_TX); return misc_register(&vhost_net_misc);}module_init(vhost_net_init);
static void __exit vhost_net_exit(void){ misc_deregister(&vhost_net_misc);}module_exit(vhost_net_exit);
MODULE_VERSION("0.0.1");MODULE_LICENSE("GPL v2");MODULE_AUTHOR("Michael S. Tsirkin");MODULE_DESCRIPTION("Host kernel accelerator for virtio net");MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);MODULE_ALIAS("devname:vhost-net");