Module Name: src
Committed By: jdolecek
Date: Sun Mar 29 15:35:31 UTC 2020
Modified Files:
src/sys/arch/xen/xen: xennetback_xenbus.c
Log Message:
in xennetback_evthandler() just copy the DomU packet into destination
mbuf via hypervisor GNTTABOP_copy op instead of mapping the buffer into
Dom0 memory
no performance difference observed for now - it would probably make more
difference if Dom0 was MP, or when Dom0 is under VM pressure
this will eventually be updated to batch copy the DomU packets
To generate a diff of this commit:
cvs rdiff -u -r1.86 -r1.87 src/sys/arch/xen/xen/xennetback_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xennetback_xenbus.c
diff -u src/sys/arch/xen/xen/xennetback_xenbus.c:1.86 src/sys/arch/xen/xen/xennetback_xenbus.c:1.87
--- src/sys/arch/xen/xen/xennetback_xenbus.c:1.86 Fri Mar 27 18:37:30 2020
+++ src/sys/arch/xen/xen/xennetback_xenbus.c Sun Mar 29 15:35:31 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: xennetback_xenbus.c,v 1.86 2020/03/27 18:37:30 jdolecek Exp $ */
+/* $NetBSD: xennetback_xenbus.c,v 1.87 2020/03/29 15:35:31 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -25,7 +25,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.86 2020/03/27 18:37:30 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.87 2020/03/29 15:35:31 jdolecek Exp $");
#include "opt_xen.h"
@@ -79,16 +79,6 @@ extern pt_entry_t xpmap_pg_nx;
/* linux wants at last 16 bytes free in front of the packet */
#define LINUX_REQUESTED_OFFSET 16
-/* hash list for TX requests */
-/* descriptor of a packet being handled by the kernel */
-struct xni_pkt {
- int pkt_id; /* packet's ID */
- grant_handle_t pkt_handle;
- struct xnetback_instance *pkt_xneti; /* pointer back to our softc */
-};
-
-/* pools for xni_pkt */
-struct pool xni_pkt_pool;
/* ratecheck(9) for pool allocation failures */
static const struct timeval xni_pool_errintvl = { 30, 0 }; /* 30s, each */
@@ -141,6 +131,7 @@ static void xennetback_frontend_changed(
static inline void xennetback_tx_response(struct xnetback_instance *,
int, int);
+static void xennetback_mbuf_addr(struct mbuf *, paddr_t *, int *);
#if 0 /* XXX */
static void xennetback_tx_free(struct mbuf * , void *, size_t, void *);
#endif /* XXX */
@@ -192,13 +183,6 @@ static struct _pages_pool_free {
} pages_pool_free[NB_XMIT_PAGES_BATCH];
-static inline void
-xni_pkt_unmap(struct xni_pkt *pkt, vaddr_t pkt_va)
-{
- xen_shm_unmap(pkt_va, 1, &pkt->pkt_handle);
- pool_put(&xni_pkt_pool, pkt);
-}
-
void
xvifattach(int n)
{
@@ -223,8 +207,6 @@ xvifattach(int n)
mcl_pages_alloc = NB_XMIT_PAGES_BATCH - 1;
/* initialise pools */
- pool_init(&xni_pkt_pool, sizeof(struct xni_pkt), 0, 0, 0,
- "xnbpkt", NULL, IPL_VM);
xmit_pages_cache = pool_cache_init(PAGE_SIZE, 0, 0, 0, "xnbxm", NULL,
IPL_VM, NULL, NULL, NULL);
@@ -732,6 +714,10 @@ xennetback_tx_check_packet(const netif_t
if (__predict_false(txreq->size > maxlen))
return "too big";
+ /* Somewhat duplicit, MCLBYTES is > ETHER_MAX_LEN */
+ if (__predict_false(txreq->size > MCLBYTES))
+ return "bigger than MCLBYTES";
+
return NULL;
}
@@ -741,11 +727,12 @@ xennetback_evthandler(void *arg)
struct xnetback_instance *xneti = arg;
struct ifnet *ifp = &xneti->xni_if;
netif_tx_request_t txreq;
- struct xni_pkt *pkt;
- vaddr_t pkt_va;
struct mbuf *m;
- int receive_pending, err;
+ int receive_pending;
RING_IDX req_cons;
+ gnttab_copy_t gop;
+ paddr_t pa;
+ int offset;
XENPRINTF(("xennetback_evthandler "));
req_cons = xneti->xni_txring.req_cons;
@@ -797,52 +784,64 @@ xennetback_evthandler(void *arg)
if_statinc(ifp, if_ierrors);
continue;
}
+ if (txreq.size > MHLEN) {
+ MCLGET(m, M_DONTWAIT);
+ if (__predict_false(m->m_ext_storage.ext_buf == NULL)) {
+ m_freem(m);
+ xennetback_tx_response(xneti, txreq.id,
+ NETIF_RSP_DROPPED);
+ if_statinc(ifp, if_ierrors);
+ continue;
+ }
+ }
XENPRINTF(("%s pkt offset %d size %d id %d req_cons %d\n",
xneti->xni_if.if_xname, txreq.offset,
txreq.size, txreq.id, MASK_NETIF_TX_IDX(req_cons)));
- pkt = pool_get(&xni_pkt_pool, PR_NOWAIT);
- if (__predict_false(pkt == NULL)) {
- static struct timeval lasttime;
- if (ratecheck(&lasttime, &xni_pool_errintvl))
- printf("%s: xnbpkt alloc failed\n",
- ifp->if_xname);
- xennetback_tx_response(xneti, txreq.id,
- NETIF_RSP_DROPPED);
- if_statinc(ifp, if_ierrors);
+ /*
+ * Copy the data and ack it. Delaying it until the mbuf is
+ * freed will stall transmit.
+ */
+ xennetback_mbuf_addr(m, &pa, &offset);
+ memset(&gop, 0, sizeof(gop));
+ gop.flags = GNTCOPY_source_gref;
+ gop.len = txreq.size;
+
+ gop.source.u.ref = txreq.gref;
+ gop.source.offset = txreq.offset;
+ gop.source.domid = xneti->xni_domid;
+
+ gop.dest.offset = offset;
+ gop.dest.domid = DOMID_SELF;
+ gop.dest.u.gmfn = xpmap_ptom(pa) >> PAGE_SHIFT;
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_copy,
+ &gop, 1) != 0) {
+ printf("%s: GNTTABOP_copy failed",
+ ifp->if_xname);
m_freem(m);
- continue;
- }
- err = xen_shm_map(1, xneti->xni_domid, &txreq.gref, &pkt_va,
- &pkt->pkt_handle, XSHM_RO);
- if (__predict_false(err == ENOMEM)) {
xennetback_tx_response(xneti, txreq.id,
- NETIF_RSP_DROPPED);
+ NETIF_RSP_ERROR);
if_statinc(ifp, if_ierrors);
- pool_put(&xni_pkt_pool, pkt);
- m_freem(m);
continue;
}
-
- if (__predict_false(err)) {
- printf("%s: mapping foreing page failed: %d\n",
- xneti->xni_if.if_xname, err);
+ if (gop.status != GNTST_okay) {
+ printf("%s GNTTABOP_copy %d\n",
+ ifp->if_xname, gop.status);
+ m_freem(m);
xennetback_tx_response(xneti, txreq.id,
NETIF_RSP_ERROR);
if_statinc(ifp, if_ierrors);
- pool_put(&xni_pkt_pool, pkt);
- m_freem(m);
continue;
}
if ((ifp->if_flags & IFF_PROMISC) == 0) {
struct ether_header *eh =
- (void*)(pkt_va + txreq.offset);
+ mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost) == 0 &&
memcmp(CLLADDR(ifp->if_sadl), eh->ether_dhost,
ETHER_ADDR_LEN) != 0) {
- xni_pkt_unmap(pkt, pkt_va);
m_freem(m);
xennetback_tx_response(xneti, txreq.id,
NETIF_RSP_OKAY);
@@ -850,23 +849,7 @@ xennetback_evthandler(void *arg)
}
}
- /*
- * This is the last TX buffer. Copy the data and
- * ack it. Delaying it until the mbuf is
- * freed will stall transmit.
- */
- m->m_len = uimin(MHLEN, txreq.size);
- m->m_pkthdr.len = 0;
- m_copyback(m, 0, txreq.size,
- (void *)(pkt_va + txreq.offset));
- xni_pkt_unmap(pkt, pkt_va);
- if (m->m_pkthdr.len < txreq.size) {
- if_statinc(ifp, if_ierrors);
- m_freem(m);
- xennetback_tx_response(xneti, txreq.id,
- NETIF_RSP_DROPPED);
- continue;
- }
+ m->m_len = m->m_pkthdr.len = txreq.size;
xennetback_tx_response(xneti, txreq.id,
NETIF_RSP_OKAY);
