This patch simplifies the netmap backend code by means of the nm_open()
helper function provided by netmap_user.h, which hides the details of
open(), iotcl() and mmap() carried out on the netmap device.

Moreover, the semantic of nm_open() makes it possible to open special
netmap ports (e.g. pipes, monitors) and use special modes (e.g. host rings
only, single queue mode, exclusive access).
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

This update was required to align error reporting of netmap backend
initialization to the modifications introduced by commit a30ecde6.
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

Reorganization of struct NetClientOptions (commit e4ba22b3) caused a
compilation failure of the netmap backend. This patch fixes the issue
by properly accessing the union field.
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

Done with following Coccinelle semantic patch, plus manual cosmetic changes in
net/*.c.

    @@
    expression E1, E2, E3, E4;
    @@
    -   qemu_set_fd_handler2(E1, NULL, E2, E3, E4);
    +   qemu_set_fd_handler(E1, E2, E3, E4);
Signed-off-by: NFam Zheng <famz@redhat.com>
Message-id: 1433400324-7358-8-git-send-email-famz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This callback is called by main loop before polling s->fd, if it returns
false, the fd will not be polled in this iteration.

This is redundant with checks inside read callback. After this patch,
the data will be copied from s->fd to s->iov when it arrives. If the
device can't receive, it will be queued to incoming_queue, and when the
device status changes, this queue will be flushed.

Also remove the qemu_can_send_packet() check in netmap_send. If it's
true, we are good; if it's false, the qemu_sendv_packet_async would
return 0 and read poll will be disabled until netmap_send_completed is
called.
Signed-off-by: NFam Zheng <famz@redhat.com>
Message-id: 1433400324-7358-5-git-send-email-famz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Error reporting for netdev_add is broken: the net_client_init_fun[]
report the actual errors with (at best) error_report(), and their
caller net_client_init1() makes up a generic error on top.

For command line and HMP, this produces an mildly ugly error cascade.

In QMP, the actual errors go to stderr, and the generic error becomes
the command's error reply.

To fix this, we need to convert the net_client_init_fun[] to Error.

To permit fixing them one by one, add an Error ** parameter to the
net_client_init_fun[].  If the call fails without returning an Error,
make up the same generic Error as before.  But if it returns one, use
that instead.  Since none of them does so far, no functional change.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1431691143-1015-3-git-send-email-armbru@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This patch fixes configure so that the netmap backend is not compiled in if the
host doesn't support an API version >= 11. A version upper bound (15) has been
added so that the netmap API can be extended with some minor features without
requiring QEMU code modifications.

Moreover, some changes have been done to net/netmap.c in order to reflect the
current netmap API/ABI (11).

The NETMAP_WITH_LIBS macro makes possible to include some utilities (e.g.
netmap ring macros, D(), RD() and other high level functions) through the netmap
headers. In this way we get rid of the D and RD macro definitions in the QEMU
code, and we open the way for further code simplifications that will be
introduced by future patches.
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This patch adds support for a network backend based on netmap.
netmap is a framework for high speed packet I/O. You can use it
to build extremely fast traffic generators, monitors, software
switches or network middleboxes. Its companion software switch
VALE lets you interconnect virtual machines.
netmap and VALE are implemented as a non-intrusive kernel module,
support NICs from multiple vendors, are part of standard FreeBSD
distributions and available in source format for Linux too.

To compile QEMU with netmap support, use the following configure
options:
    ./configure [...] --enable-netmap --extra-cflags=-I/path/to/netmap/sys
where "/path/to/netmap" contains the netmap source code, available at
    http://info.iet.unipi.it/~luigi/netmap/

The same webpage contains more information about the netmap project
(together with papers and presentations).
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>