[Qemu-devel] [PATCH v3 0/5] Add netmap backend offloadings support

[Qemu-devel] [PATCH v3 0/5] Add netmap backend offloadings support

[Vincenzo Maffione]

The purpose of this patch series is to add offloadings support
(TSO/UFO/CSUM) to the netmap network backend, and make it possible
for the paravirtual network frontends (virtio-net and vmxnet3) to
use it.
In order to achieve this, these patches extend the existing
net.h interface to add abstract operations through which a network
frontend can manipulate backend offloading features, instead of
directly calling TAP-specific functions.

Guest-to-guest performance before this patches for virtio-net + netmap:

    TCP_STREAM                  5.0 Gbps
    TCP_RR                      12.7 Gbps
    UDP_STREAM (64-bytes)       790 Kpps

Guest-to-guest performance after this patches for virtio-net + netmap:

    TCP_STREAM                  21.4 Gbps
    TCP_RR                      12.7 Gbps
    UDP_STREAM (64-bytes)       790 Kpps

Experiment details:
    - Processor: Intel i7-3770K CPU @ 3.50GHz (8 cores)
    - Memory @ 1333 MHz
    - Host O.S.: Archlinux with Linux 3.11
    - Guest O.S.: Archlinux with Linux 3.11

    - QEMU command line:
        qemu-system-x86_64 archdisk.qcow -snapshot -enable-kvm -device virtio-net-pci,ioeventfd=on,mac=00:AA:BB:CC:DD:01,netdev=mynet -netdev netmap,ifname=vale0:01,id=mynet -smp 2 -vga std -m 3G


******** Changes against the previous version ***********
NOTE: Now the VALE switch supports the offloadings, meaning that TCP/UDP will work
      even between a virtio-net guest with offloadings enabled and another
      guest with offloadings disabled. This has been achieved without performance loss
      on the "fast" case (e.g. two virtio-net-guest communicating with offloadings on).

(1) removed the second commit of the previous version, which was
    intended to remove tap_using_vnet_hdr()
(2) the last commit has been revised: NETMAP_BDG_OFFSET becomes
    NETMAP_BDG_VNET_HDR, netmap_set_offload() implemented and
    netmap_has_vnet_hdr_len() rewritten.


Vincenzo Maffione (5):
  net: change vnet-hdr TAP prototypes
  net: extend NetClientInfo for offloading
  net: TAP uses NetClientInfo offloading callbacks
  net: virtio-net and vmxnet3 use offloading API
  net: add offloading support to netmap backend

 hw/net/virtio-net.c | 16 +++++--------
 hw/net/vmxnet3.c    | 12 ++++------
 include/net/net.h   | 19 +++++++++++++++
 include/net/tap.h   |  4 ++--
 net/net.c           | 55 +++++++++++++++++++++++++++++++++++++++++++
 net/netmap.c        | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 net/tap-win32.c     |  8 +++----
 net/tap.c           | 12 +++++++---
 8 files changed, 167 insertions(+), 27 deletions(-)

-- 
1.8.5.2

[Qemu-devel] [PATCH v3 1/5] net: change vnet-hdr TAP prototypes

[Vincenzo Maffione]

The tap_has_vnet_hdr() and tap_has_vnet_hdr_len() functions used
to return int, even though they only return true/false values.
This patch changes the prototypes to return bool.

Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
---
 include/net/tap.h | 4 ++--
 net/tap-win32.c   | 8 ++++----
 net/tap.c         | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/net/tap.h b/include/net/tap.h
index a994f20..a3490a9 100644
--- a/include/net/tap.h
+++ b/include/net/tap.h
@@ -30,8 +30,8 @@
 #include "qapi-types.h"
 
 bool tap_has_ufo(NetClientState *nc);
-int tap_has_vnet_hdr(NetClientState *nc);
-int tap_has_vnet_hdr_len(NetClientState *nc, int len);
+bool tap_has_vnet_hdr(NetClientState *nc);
+bool tap_has_vnet_hdr_len(NetClientState *nc, int len);
 void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr);
 void tap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, int ufo);
 void tap_set_vnet_hdr_len(NetClientState *nc, int len);
diff --git a/net/tap-win32.c b/net/tap-win32.c
index 91e9e84..edf26c4 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -727,9 +727,9 @@ bool tap_has_ufo(NetClientState *nc)
     return false;
 }
 
-int tap_has_vnet_hdr(NetClientState *nc)
+bool tap_has_vnet_hdr(NetClientState *nc)
 {
-    return 0;
+    return false;
 }
 
 int tap_probe_vnet_hdr_len(int fd, int len)
@@ -755,9 +755,9 @@ struct vhost_net *tap_get_vhost_net(NetClientState *nc)
     return NULL;
 }
 
-int tap_has_vnet_hdr_len(NetClientState *nc, int len)
+bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
 {
-    return 0;
+    return false;
 }
 
 void tap_set_vnet_hdr_len(NetClientState *nc, int len)
diff --git a/net/tap.c b/net/tap.c
index 39c1cda..c805f3c 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -219,7 +219,7 @@ bool tap_has_ufo(NetClientState *nc)
     return s->has_ufo;
 }
 
-int tap_has_vnet_hdr(NetClientState *nc)
+bool tap_has_vnet_hdr(NetClientState *nc)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
 
@@ -228,13 +228,13 @@ int tap_has_vnet_hdr(NetClientState *nc)
     return !!s->host_vnet_hdr_len;
 }
 
-int tap_has_vnet_hdr_len(NetClientState *nc, int len)
+bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
 
     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
 
-    return tap_probe_vnet_hdr_len(s->fd, len);
+    return !!tap_probe_vnet_hdr_len(s->fd, len);
 }
 
 void tap_set_vnet_hdr_len(NetClientState *nc, int len)
-- 
1.8.5.2

[Qemu-devel] [PATCH v3 2/5] net: extend NetClientInfo for offloading

[Vincenzo Maffione]

Some new callbacks have been added to generalize the operations done
by virtio-net and vmxnet3 frontends to manipulate TAP offloadings.

Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
---
 include/net/net.h | 19 +++++++++++++++++++
 net/net.c         | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/include/net/net.h b/include/net/net.h
index 11e1468..7b25394 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -50,6 +50,12 @@ typedef void (NetCleanup) (NetClientState *);
 typedef void (LinkStatusChanged)(NetClientState *);
 typedef void (NetClientDestructor)(NetClientState *);
 typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
+typedef bool (HasUfo)(NetClientState *);
+typedef bool (HasVnetHdr)(NetClientState *);
+typedef bool (HasVnetHdrLen)(NetClientState *, int);
+typedef void (UsingVnetHdr)(NetClientState *, bool);
+typedef void (SetOffload)(NetClientState *, int, int, int, int, int);
+typedef void (SetVnetHdrLen)(NetClientState *, int);
 
 typedef struct NetClientInfo {
     NetClientOptionsKind type;
@@ -62,6 +68,12 @@ typedef struct NetClientInfo {
     LinkStatusChanged *link_status_changed;
     QueryRxFilter *query_rx_filter;
     NetPoll *poll;
+    HasUfo *has_ufo;
+    HasVnetHdr *has_vnet_hdr;
+    HasVnetHdrLen *has_vnet_hdr_len;
+    UsingVnetHdr *using_vnet_hdr;
+    SetOffload *set_offload;
+    SetVnetHdrLen *set_vnet_hdr_len;
 } NetClientInfo;
 
 struct NetClientState {
@@ -120,6 +132,13 @@ ssize_t qemu_send_packet_async(NetClientState *nc, const uint8_t *buf,
 void qemu_purge_queued_packets(NetClientState *nc);
 void qemu_flush_queued_packets(NetClientState *nc);
 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]);
+bool qemu_peer_has_ufo(NetClientState *nc);
+bool qemu_peer_has_vnet_hdr(NetClientState *nc);
+bool qemu_peer_has_vnet_hdr_len(NetClientState *nc, int len);
+void qemu_peer_using_vnet_hdr(NetClientState *nc, bool enable);
+void qemu_peer_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
+                           int ecn, int ufo);
+void qemu_peer_set_vnet_hdr_len(NetClientState *nc, int len);
 void qemu_macaddr_default_if_unset(MACAddr *macaddr);
 int qemu_show_nic_models(const char *arg, const char *const *models);
 void qemu_check_nic_model(NICInfo *nd, const char *model);
diff --git a/net/net.c b/net/net.c
index f8db85f..0a31c95 100644
--- a/net/net.c
+++ b/net/net.c
@@ -381,6 +381,61 @@ void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
     }
 }
 
+bool qemu_peer_has_ufo(NetClientState *nc)
+{
+    if (!nc->peer || !nc->peer->info->has_ufo) {
+        return false;
+    }
+
+    return nc->peer->info->has_ufo(nc->peer);
+}
+
+bool qemu_peer_has_vnet_hdr(NetClientState *nc)
+{
+    if (!nc->peer || !nc->peer->info->has_vnet_hdr) {
+        return false;
+    }
+
+    return nc->peer->info->has_vnet_hdr(nc->peer);
+}
+
+bool qemu_peer_has_vnet_hdr_len(NetClientState *nc, int len)
+{
+    if (!nc->peer || !nc->peer->info->has_vnet_hdr_len) {
+        return false;
+    }
+
+    return nc->peer->info->has_vnet_hdr_len(nc->peer, len);
+}
+
+void qemu_peer_using_vnet_hdr(NetClientState *nc, bool enable)
+{
+    if (!nc->peer || !nc->peer->info->using_vnet_hdr) {
+        return;
+    }
+
+    nc->peer->info->using_vnet_hdr(nc->peer, enable);
+}
+
+void qemu_peer_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
+                          int ecn, int ufo)
+{
+    if (!nc->peer || !nc->peer->info->set_offload) {
+        return;
+    }
+
+    nc->peer->info->set_offload(nc->peer, csum, tso4, tso6, ecn, ufo);
+}
+
+void qemu_peer_set_vnet_hdr_len(NetClientState *nc, int len)
+{
+    if (!nc->peer || !nc->peer->info->set_vnet_hdr_len) {
+        return;
+    }
+
+    nc->peer->info->set_vnet_hdr_len(nc->peer, len);
+}
+
 int qemu_can_send_packet(NetClientState *sender)
 {
     if (!sender->peer) {
-- 
1.8.5.2

[Qemu-devel] [PATCH v3 3/5] net: TAP uses NetClientInfo offloading callbacks

[Vincenzo Maffione]

The TAP NetClientInfo structure is inizialized with the TAP-specific
functions that manipulates offloading features.

Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
---
 net/tap.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/tap.c b/net/tap.c
index c805f3c..d34ec88 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -314,6 +314,12 @@ static NetClientInfo net_tap_info = {
     .receive_iov = tap_receive_iov,
     .poll = tap_poll,
     .cleanup = tap_cleanup,
+    .has_ufo = tap_has_ufo,
+    .has_vnet_hdr = tap_has_vnet_hdr,
+    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
+    .using_vnet_hdr = tap_using_vnet_hdr,
+    .set_offload = tap_set_offload,
+    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
 };
 
 static TAPState *net_tap_fd_init(NetClientState *peer,
-- 
1.8.5.2

Re: [Qemu-devel] [PATCH v3 3/5] net: TAP uses NetClientInfo offloading callbacks

[Stefan Hajnoczi]

On Mon, Jan 20, 2014 at 06:07:03PM +0100, Vincenzo Maffione wrote:
> The TAP NetClientInfo structure is inizialized with the TAP-specific
> functions that manipulates offloading features.
> 
> Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
> ---
>  net/tap.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/net/tap.c b/net/tap.c
> index c805f3c..d34ec88 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -314,6 +314,12 @@ static NetClientInfo net_tap_info = {
>      .receive_iov = tap_receive_iov,
>      .poll = tap_poll,
>      .cleanup = tap_cleanup,
> +    .has_ufo = tap_has_ufo,
> +    .has_vnet_hdr = tap_has_vnet_hdr,
> +    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
> +    .using_vnet_hdr = tap_using_vnet_hdr,
> +    .set_offload = tap_set_offload,
> +    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
>  };
>  
>  static TAPState *net_tap_fd_init(NetClientState *peer,

Please make these tap_*() functions static.  They do not need to be
accessed from outside this source file.

I also noticed that you didn't touch tap-win32.c.  I guess it should
also assign its tap_has_ufo() and similar functions.  (tap-win32.c
declares its own net_tap_info struct.)  Here, we can also make the
functions static.

Re: [Qemu-devel] [PATCH v3 3/5] net: TAP uses NetClientInfo offloading callbacks

[Stefan Hajnoczi]

On Mon, Jan 20, 2014 at 06:07:03PM +0100, Vincenzo Maffione wrote:
> The TAP NetClientInfo structure is inizialized with the TAP-specific
> functions that manipulates offloading features.
> 
> Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
> ---
>  net/tap.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/net/tap.c b/net/tap.c
> index c805f3c..d34ec88 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -314,6 +314,12 @@ static NetClientInfo net_tap_info = {
>      .receive_iov = tap_receive_iov,
>      .poll = tap_poll,
>      .cleanup = tap_cleanup,
> +    .has_ufo = tap_has_ufo,
> +    .has_vnet_hdr = tap_has_vnet_hdr,
> +    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
> +    .using_vnet_hdr = tap_using_vnet_hdr,
> +    .set_offload = tap_set_offload,
> +    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
>  };

Regarding making functions static: that has to be done after the next
patch since vhost-net is still calling tap_*() directly here.  It can be
a new patch later in this series.

Re: [Qemu-devel] [PATCH v3 3/5] net: TAP uses NetClientInfo offloading callbacks

[Vincenzo Maffione]

[-- Attachment #1: Type: text/plain, Size: 1187 bytes --]

Ok, It could go as patch 5/6.

Thanks


2014-02-06 Stefan Hajnoczi <stefanha@redhat.com>:

> On Mon, Jan 20, 2014 at 06:07:03PM +0100, Vincenzo Maffione wrote:
> > The TAP NetClientInfo structure is inizialized with the TAP-specific
> > functions that manipulates offloading features.
> >
> > Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
> > ---
> >  net/tap.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/net/tap.c b/net/tap.c
> > index c805f3c..d34ec88 100644
> > --- a/net/tap.c
> > +++ b/net/tap.c
> > @@ -314,6 +314,12 @@ static NetClientInfo net_tap_info = {
> >      .receive_iov = tap_receive_iov,
> >      .poll = tap_poll,
> >      .cleanup = tap_cleanup,
> > +    .has_ufo = tap_has_ufo,
> > +    .has_vnet_hdr = tap_has_vnet_hdr,
> > +    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
> > +    .using_vnet_hdr = tap_using_vnet_hdr,
> > +    .set_offload = tap_set_offload,
> > +    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
> >  };
>
> Regarding making functions static: that has to be done after the next
> patch since vhost-net is still calling tap_*() directly here.  It can be
> a new patch later in this series.
>



-- 
Vincenzo Maffione

[-- Attachment #2: Type: text/html, Size: 1787 bytes --]

[Qemu-devel] [PATCH v3 4/5] net: virtio-net and vmxnet3 use offloading API

[Vincenzo Maffione]

With this patch, virtio-net and vmxnet3 frontends make
use of the qemu_peer_* API for backend offloadings manipulations,
instead of calling TAP-specific functions directly.
We also remove the existing checks which prevent those frontends
from using offloadings with backends different from TAP (e.g. netmap).

Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
---
 hw/net/virtio-net.c | 16 ++++++----------
 hw/net/vmxnet3.c    | 12 +++++-------
 2 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3626608..00c149b 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -325,11 +325,7 @@ static void peer_test_vnet_hdr(VirtIONet *n)
         return;
     }
 
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
-    }
-
-    n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
+    n->has_vnet_hdr = qemu_peer_has_vnet_hdr(nc);
 }
 
 static int peer_has_vnet_hdr(VirtIONet *n)
@@ -342,7 +338,7 @@ static int peer_has_ufo(VirtIONet *n)
     if (!peer_has_vnet_hdr(n))
         return 0;
 
-    n->has_ufo = tap_has_ufo(qemu_get_queue(n->nic)->peer);
+    n->has_ufo = qemu_peer_has_ufo(qemu_get_queue(n->nic));
 
     return n->has_ufo;
 }
@@ -361,8 +357,8 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs)
         nc = qemu_get_subqueue(n->nic, i);
 
         if (peer_has_vnet_hdr(n) &&
-            tap_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
-            tap_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
+            qemu_peer_has_vnet_hdr_len(nc, n->guest_hdr_len)) {
+            qemu_peer_set_vnet_hdr_len(nc, n->guest_hdr_len);
             n->host_hdr_len = n->guest_hdr_len;
         }
     }
@@ -463,7 +459,7 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 
 static void virtio_net_apply_guest_offloads(VirtIONet *n)
 {
-    tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,
+    qemu_peer_set_offload(qemu_get_subqueue(n->nic, 0),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
@@ -1544,7 +1540,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     peer_test_vnet_hdr(n);
     if (peer_has_vnet_hdr(n)) {
         for (i = 0; i < n->max_queues; i++) {
-            tap_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
+            qemu_peer_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
         }
         n->host_hdr_len = sizeof(struct virtio_net_hdr);
     } else {
diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index 19687aa..4ad3bf0 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -1290,7 +1290,7 @@ static void vmxnet3_update_features(VMXNET3State *s)
               s->lro_supported, rxcso_supported,
               s->rx_vlan_stripping);
     if (s->peer_has_vhdr) {
-        tap_set_offload(qemu_get_queue(s->nic)->peer,
+        qemu_peer_set_offload(qemu_get_queue(s->nic),
                         rxcso_supported,
                         s->lro_supported,
                         s->lro_supported,
@@ -1883,11 +1883,9 @@ static NetClientInfo net_vmxnet3_info = {
 
 static bool vmxnet3_peer_has_vnet_hdr(VMXNET3State *s)
 {
-    NetClientState *peer = qemu_get_queue(s->nic)->peer;
+    NetClientState *nc = qemu_get_queue(s->nic);
 
-    if ((NULL != peer)                              &&
-        (peer->info->type == NET_CLIENT_OPTIONS_KIND_TAP)   &&
-        tap_has_vnet_hdr(peer)) {
+    if (qemu_peer_has_vnet_hdr(nc)) {
         return true;
     }
 
@@ -1935,10 +1933,10 @@ static void vmxnet3_net_init(VMXNET3State *s)
     s->lro_supported = false;
 
     if (s->peer_has_vhdr) {
-        tap_set_vnet_hdr_len(qemu_get_queue(s->nic)->peer,
+        qemu_peer_set_vnet_hdr_len(qemu_get_queue(s->nic),
             sizeof(struct virtio_net_hdr));
 
-        tap_using_vnet_hdr(qemu_get_queue(s->nic)->peer, 1);
+        qemu_peer_using_vnet_hdr(qemu_get_queue(s->nic)->peer, 1);
     }
 
     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
-- 
1.8.5.2

[Qemu-devel] [PATCH v3 5/5] net: add offloading support to netmap backend

[Vincenzo Maffione]

Whit this patch, the netmap backend supports TSO/UFO/CSUM
offloadings, and accepts the virtio-net header, similarly to what
happens with TAP. The offloading callbacks in the NetClientInfo
interface have been implemented.

Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
---
 net/netmap.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/net/netmap.c b/net/netmap.c
index 0ccc497..73f6d7a 100644
--- a/net/netmap.c
+++ b/net/netmap.c
@@ -31,6 +31,7 @@
 #include <net/netmap_user.h>
 
 #include "net/net.h"
+#include "net/tap.h"
 #include "clients.h"
 #include "sysemu/sysemu.h"
 #include "qemu/error-report.h"
@@ -54,6 +55,7 @@ typedef struct NetmapState {
     bool                read_poll;
     bool                write_poll;
     struct iovec        iov[IOV_MAX];
+    int                 vnet_hdr_len;  /* Current virtio-net header length. */
 } NetmapState;
 
 #define D(format, ...)                                          \
@@ -274,7 +276,7 @@ static ssize_t netmap_receive_iov(NetClientState *nc,
         return iov_size(iov, iovcnt);
     }
 
-    i = ring->cur;
+    last = i = ring->cur;
     avail = ring->avail;
 
     if (avail < iovcnt) {
@@ -394,6 +396,63 @@ static void netmap_cleanup(NetClientState *nc)
     s->me.fd = -1;
 }
 
+/* Offloading manipulation support callbacks. */
+static bool netmap_has_ufo(NetClientState *nc)
+{
+    return true;
+}
+
+static bool netmap_has_vnet_hdr(NetClientState *nc)
+{
+    return true;
+}
+
+static bool netmap_has_vnet_hdr_len(NetClientState *nc, int len)
+{
+    return len == 0 || len == sizeof(struct virtio_net_hdr) ||
+                len == sizeof(struct virtio_net_hdr_mrg_rxbuf);
+}
+
+static void netmap_using_vnet_hdr(NetClientState *nc, bool enable)
+{
+}
+
+static void netmap_set_vnet_hdr_len(NetClientState *nc, int len)
+{
+    NetmapState *s = DO_UPCAST(NetmapState, nc, nc);
+    int err;
+    struct nmreq req;
+
+    /* Issue a NETMAP_BDG_VNET_HDR command to change the virtio-net header
+     * length for the netmap adapter associated to 'me->ifname'.
+     */
+    memset(&req, 0, sizeof(req));
+    pstrcpy(req.nr_name, sizeof(req.nr_name), s->me.ifname);
+    req.nr_version = NETMAP_API;
+    req.nr_cmd = NETMAP_BDG_VNET_HDR;
+    req.nr_arg1 = len;
+    err = ioctl(s->me.fd, NIOCREGIF, &req);
+    if (err) {
+        error_report("Unable to execute NETMAP_BDG_VNET_HDR on %s: %s",
+                     s->me.ifname, strerror(errno));
+    } else {
+        /* Keep track of the current length. */
+        s->vnet_hdr_len = len;
+    }
+}
+
+static void netmap_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
+                               int ecn, int ufo)
+{
+    NetmapState *s = DO_UPCAST(NetmapState, nc, nc);
+
+    /* Setting a virtio-net header length greater than zero automatically
+     * enables the offloadings.
+     */
+    if (!s->vnet_hdr_len) {
+        netmap_set_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr));
+    }
+}
 
 /* NetClientInfo methods */
 static NetClientInfo net_netmap_info = {
@@ -403,6 +462,12 @@ static NetClientInfo net_netmap_info = {
     .receive_iov = netmap_receive_iov,
     .poll = netmap_poll,
     .cleanup = netmap_cleanup,
+    .has_ufo = netmap_has_ufo,
+    .has_vnet_hdr = netmap_has_vnet_hdr,
+    .has_vnet_hdr_len = netmap_has_vnet_hdr_len,
+    .using_vnet_hdr = netmap_using_vnet_hdr,
+    .set_offload = netmap_set_offload,
+    .set_vnet_hdr_len = netmap_set_vnet_hdr_len,
 };
 
 /* The exported init function
@@ -428,6 +493,7 @@ int net_init_netmap(const NetClientOptions *opts,
     nc = qemu_new_net_client(&net_netmap_info, peer, "netmap", name);
     s = DO_UPCAST(NetmapState, nc, nc);
     s->me = me;
+    s->vnet_hdr_len = 0;
     netmap_read_poll(s, true); /* Initially only poll for reads. */
 
     return 0;
-- 
1.8.5.2

Re: [Qemu-devel] [PATCH v3 0/5] Add netmap backend offloadings support

[Vincenzo Maffione]

[-- Attachment #1: Type: text/plain, Size: 2836 bytes --]

ping

Cheers
  Vincenzo


2014-01-20 Vincenzo Maffione <v.maffione@gmail.com>:

> The purpose of this patch series is to add offloadings support
> (TSO/UFO/CSUM) to the netmap network backend, and make it possible
> for the paravirtual network frontends (virtio-net and vmxnet3) to
> use it.
> In order to achieve this, these patches extend the existing
> net.h interface to add abstract operations through which a network
> frontend can manipulate backend offloading features, instead of
> directly calling TAP-specific functions.
>
> Guest-to-guest performance before this patches for virtio-net + netmap:
>
>     TCP_STREAM                  5.0 Gbps
>     TCP_RR                      12.7 Gbps
>     UDP_STREAM (64-bytes)       790 Kpps
>
> Guest-to-guest performance after this patches for virtio-net + netmap:
>
>     TCP_STREAM                  21.4 Gbps
>     TCP_RR                      12.7 Gbps
>     UDP_STREAM (64-bytes)       790 Kpps
>
> Experiment details:
>     - Processor: Intel i7-3770K CPU @ 3.50GHz (8 cores)
>     - Memory @ 1333 MHz
>     - Host O.S.: Archlinux with Linux 3.11
>     - Guest O.S.: Archlinux with Linux 3.11
>
>     - QEMU command line:
>         qemu-system-x86_64 archdisk.qcow -snapshot -enable-kvm -device
> virtio-net-pci,ioeventfd=on,mac=00:AA:BB:CC:DD:01,netdev=mynet -netdev
> netmap,ifname=vale0:01,id=mynet -smp 2 -vga std -m 3G
>
>
> ******** Changes against the previous version ***********
> NOTE: Now the VALE switch supports the offloadings, meaning that TCP/UDP
> will work
>       even between a virtio-net guest with offloadings enabled and another
>       guest with offloadings disabled. This has been achieved without
> performance loss
>       on the "fast" case (e.g. two virtio-net-guest communicating with
> offloadings on).
>
> (1) removed the second commit of the previous version, which was
>     intended to remove tap_using_vnet_hdr()
> (2) the last commit has been revised: NETMAP_BDG_OFFSET becomes
>     NETMAP_BDG_VNET_HDR, netmap_set_offload() implemented and
>     netmap_has_vnet_hdr_len() rewritten.
>
>
> Vincenzo Maffione (5):
>   net: change vnet-hdr TAP prototypes
>   net: extend NetClientInfo for offloading
>   net: TAP uses NetClientInfo offloading callbacks
>   net: virtio-net and vmxnet3 use offloading API
>   net: add offloading support to netmap backend
>
>  hw/net/virtio-net.c | 16 +++++--------
>  hw/net/vmxnet3.c    | 12 ++++------
>  include/net/net.h   | 19 +++++++++++++++
>  include/net/tap.h   |  4 ++--
>  net/net.c           | 55 +++++++++++++++++++++++++++++++++++++++++++
>  net/netmap.c        | 68
> ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  net/tap-win32.c     |  8 +++----
>  net/tap.c           | 12 +++++++---
>  8 files changed, 167 insertions(+), 27 deletions(-)
>
> --
> 1.8.5.2
>
>


-- 
Vincenzo Maffione

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Re: [Qemu-devel] [PATCH v3 0/5] Add netmap backend offloadings support

[Stefan Hajnoczi]

On Mon, Jan 20, 2014 at 06:07:00PM +0100, Vincenzo Maffione wrote:
> The purpose of this patch series is to add offloadings support
> (TSO/UFO/CSUM) to the netmap network backend, and make it possible
> for the paravirtual network frontends (virtio-net and vmxnet3) to
> use it.
> In order to achieve this, these patches extend the existing
> net.h interface to add abstract operations through which a network
> frontend can manipulate backend offloading features, instead of
> directly calling TAP-specific functions.
> 
> Guest-to-guest performance before this patches for virtio-net + netmap:
> 
>     TCP_STREAM                  5.0 Gbps
>     TCP_RR                      12.7 Gbps
>     UDP_STREAM (64-bytes)       790 Kpps
> 
> Guest-to-guest performance after this patches for virtio-net + netmap:
> 
>     TCP_STREAM                  21.4 Gbps
>     TCP_RR                      12.7 Gbps
>     UDP_STREAM (64-bytes)       790 Kpps
> 
> Experiment details:
>     - Processor: Intel i7-3770K CPU @ 3.50GHz (8 cores)
>     - Memory @ 1333 MHz
>     - Host O.S.: Archlinux with Linux 3.11
>     - Guest O.S.: Archlinux with Linux 3.11
> 
>     - QEMU command line:
>         qemu-system-x86_64 archdisk.qcow -snapshot -enable-kvm -device virtio-net-pci,ioeventfd=on,mac=00:AA:BB:CC:DD:01,netdev=mynet -netdev netmap,ifname=vale0:01,id=mynet -smp 2 -vga std -m 3G
> 
> 
> ******** Changes against the previous version ***********
> NOTE: Now the VALE switch supports the offloadings, meaning that TCP/UDP will work
>       even between a virtio-net guest with offloadings enabled and another
>       guest with offloadings disabled. This has been achieved without performance loss
>       on the "fast" case (e.g. two virtio-net-guest communicating with offloadings on).
> 
> (1) removed the second commit of the previous version, which was
>     intended to remove tap_using_vnet_hdr()
> (2) the last commit has been revised: NETMAP_BDG_OFFSET becomes
>     NETMAP_BDG_VNET_HDR, netmap_set_offload() implemented and
>     netmap_has_vnet_hdr_len() rewritten.
> 
> 
> Vincenzo Maffione (5):
>   net: change vnet-hdr TAP prototypes
>   net: extend NetClientInfo for offloading
>   net: TAP uses NetClientInfo offloading callbacks
>   net: virtio-net and vmxnet3 use offloading API
>   net: add offloading support to netmap backend
> 
>  hw/net/virtio-net.c | 16 +++++--------
>  hw/net/vmxnet3.c    | 12 ++++------
>  include/net/net.h   | 19 +++++++++++++++
>  include/net/tap.h   |  4 ++--
>  net/net.c           | 55 +++++++++++++++++++++++++++++++++++++++++++
>  net/netmap.c        | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  net/tap-win32.c     |  8 +++----
>  net/tap.c           | 12 +++++++---
>  8 files changed, 167 insertions(+), 27 deletions(-)

Look good but we should finish by making tap_*() static and adding the
missing function pointer assignments in tap-win32.c.