QEMU serial communication between guest and host

I'm running an Linux Image (kernel 3.2.8) for beagleboard-xm on QEMU's 1.4.0

qemu call cmd:

sudo qemu-system-arm -M beaglexm -m 1024 -sd ./test.img -clock unix -serial
stdio -device usb-mouse -device usb-kbd -chardev tty,id=tty,path=ttyS0
What I want to do is to have a communication between guest and host across
serial the 4 differents ttyO present on the guest. QEMU offer facilities to
redirect the trafic to some device in the host side. My problem goes like

At the guest kernel boot Im able to see that my UART where enabled

[ 2.682040] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[ 2.777947] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 72) is a OMAP
[ 2.794967] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 73) is a OMAP
[ 2.814942] omap_uart.2: ttyO2 at MMIO 0x49020000 (irq = 74) is a OMAP
[ 2.966825] console [ttyO2] enabled
[ 2.984777] omap_uart.3: ttyO3 at MMIO 0x49042000 (irq = 80) is a OMAP
In fact when I go see in to /proc/tty/driver and I do a cat on OMAP-SERIAL
Im able to see this serinfo:1.0 driver revision:

0: uart:OMAP UART0 mmio:0x4806A000 irq:72 tx:0 rx:0 CTS|DSR|CD
1: uart:OMAP UART1 mmio:0x4806C000 irq:73 tx:0 rx:0 CTS|DSR|CD
2: uart:OMAP UART2 mmio:0x49020000 irq:74 tx:268 rx:37 RTS|CTS|DTR|DSR|CD
3: uart:OMAP UART3 mmio:0x49042000 irq:80 tx:0 rx:0 CTS|DSR|CD
I know that ttyO2 is working because my console is been redirected to it.
The thing is that doing a set serial on any of the ttyO I get the following

[root@enu driver]# setserial -a /dev/ttyO0
/dev/ttyO0, Line 0, UART: undefined, Port: 0x0000, IRQ: 72
    Baud_base: 3000000, close_delay: 50, divisor: 0
    closing_wait: 3000
    Flags: spd_normal
The same goes with ttyO2. I tried to set some settings to any of the ttyO
with setserial but I always get the same message:

[root@enu ~]# setserial /dev/ttyO0 uart 8250
setserial: can't set serial info: Invalid argument
[root@enu ~]# setserial /dev/ttyO0 port 0x4806a000
setserial: can't set serial info: Invalid argument
While looking at guest /proc/tty/drives this is what we see

/dev/tty /dev/tty 5 0 system:/dev/tty
/dev/console /dev/console 5 1 system:console
/dev/ptmx /dev/ptmx 5 2 system
/dev/vc/0 /dev/vc/0 4 0 system:vtmaster
sdio_uart /dev/ttySDIO 249 0-7 serial
acm /dev/ttyACM 166 0-31 serial
ttyprintk /dev/ttyprintk 5 3 console
OMAP-SERIAL /dev/ttyO 253 0-3 serial
serial /dev/ttyS 4 64-95 serial
pty_slave /dev/pts 136 0-1048575 pty:slave
pty_master /dev/ptm 128 0-1048575 pty:master
unknown /dev/tty 4 1-63 console
Basically I want to establish a serial communication between a guest and a
host, but the serial ports on the guest side aren't well configured.

PS: I also tryied with -serial arg on qemu's cmd call and nothing.

Can someone help me?