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Re: [Qemu-devel] QEMU network probes
- From: Stefan Hajnoczi <stefanha at gmail dot com>
- To: Rayson Ho <rho at redhat dot com>
- Cc: qemu-devel at nongnu dot org, systemtap at sources dot redhat dot com
- Date: Thu, 10 Feb 2011 11:12:50 +0000
- Subject: Re: [Qemu-devel] QEMU network probes
- References: <1283952030.2631.19.camel@computer> <AANLkTimbrDwhHOZxWiWhzKQgt=yq6N7GWkGHtJK3sHSR@mail.gmail.com> <1284988762.2500.13.camel@computer> <AANLkTikr3eRT27r9w23_G89oxrMDhtukW4vN9UUhuMwH@mail.gmail.com> <1285073887.2566.39.camel@computer> <AANLkTimyTLoBt8mCdEDJWmCFycKUW8DSN+K=z39LYF_T@mail.gmail.com> <1285157490.6879.23.camel@computer> <AANLkTi=Sy3qJxXADiSyt+sBK7cP9p=0cnFj6-V_RCSPT@mail.gmail.com> <1285159357.6879.31.camel@computer> <AANLkTi=OquAwjs6Rbbh0nCNPSjVt+bKcNUrFGKRjQani@mail.gmail.com> <1290019040.2454.3.camel@computer> <AANLkTi=sf_v_SxLR1vNB7JwqU-KUcM2QVmYLn9MJyds4@mail.gmail.com> <1290626577.7673.2.camel@computer> <AANLkTikta_R78LFf9_=OH1U3+HXSz0xepOWmYR8QV=qD@mail.gmail.com> <1297279651.2295.23.camel@computer>
On Wed, Feb 9, 2011 at 7:27 PM, Rayson Ho <rho@redhat.com> wrote:
> Please review the probe addition in QEMU for the network module, note
> that I added probes for send & receive Ethernet frames for rtl8139 so
> far but not other network devices. Also for receive, the probe would
> only fire when a frame is successfully received, so any errors are
> ignored.
I don't know the network subsystem well so I hope others can comment on that.
> =========================================================================
>
> diff --git a/hw/rtl8139.c b/hw/rtl8139.c
> index a22530c..df04f59 100644
> --- a/hw/rtl8139.c
> +++ b/hw/rtl8139.c
> @@ -53,6 +53,7 @@
> ?#include "net.h"
> ?#include "loader.h"
> ?#include "sysemu.h"
> +#include "trace.h"
>
> ?/* debug RTL8139 card */
> ?//#define DEBUG_RTL8139 1
> @@ -1160,6 +1161,8 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
> ? ? ? ? rtl8139_update_irq(s);
> ? ? }
>
> + ? ?trace_rtl8139_do_receive(nc, buf, size_, do_interrupt);
> +
> ? ? return size_;
> ?}
>
The rtl8139 has a lot of DEBUG_PRINT(). Have you thought about
converting those?
> @@ -1742,6 +1745,8 @@ static uint32_t rtl8139_RxConfig_read(RTL8139State *s)
>
> ?static void rtl8139_transfer_frame(RTL8139State *s, const uint8_t *buf, int size, int do_interrupt)
> ?{
> + ? ?trace_rtl8139_transfer_frame(s, buf, size, do_interrupt);
> +
> ? ? if (!size)
> ? ? {
> ? ? ? ? DEBUG_PRINT(("RTL8139: +++ empty ethernet frame\n"));
> diff --git a/net.c b/net.c
> index 9ba5be2..ba74f74 100644
> --- a/net.c
> +++ b/net.c
> @@ -36,6 +36,7 @@
> ?#include "qemu-common.h"
> ?#include "qemu_socket.h"
> ?#include "hw/qdev.h"
> +#include "trace.h"
>
> ?static QTAILQ_HEAD(, VLANState) vlans;
> ?static QTAILQ_HEAD(, VLANClientState) non_vlan_clients;
> @@ -559,6 +560,7 @@ ssize_t qemu_send_packet_async(VLANClientState *sender,
>
> ?void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size)
> ?{
> + ? ?trace_qemu_send_packet(vc, buf, size);
> ? ? qemu_send_packet_async(vc, buf, size, NULL);
> ?}
>
All qemu_send_*() functions go through
qemu_send_packet_async_with_flags(). Lets put the trace event there
(there's already a printf), and include the sender, queue, buf, size,
and return value. That way it's possible to trace all net traffic
including non-rtl8139.
> diff --git a/trace-events b/trace-events
> index e6138ea..76a8431 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -254,3 +254,10 @@ disable spice_vmc_write(ssize_t out, int len) "spice wrottn %lu of requested %zd
> ?disable spice_vmc_read(int bytes, int len) "spice read %lu of requested %zd"
> ?disable spice_vmc_register_interface(void *scd) "spice vmc registered interface %p"
> ?disable spice_vmc_unregister_interface(void *scd) "spice vmc unregistered interface %p"
> +
> +# net.c
> +disable qemu_send_packet(void *vc, const uint8_t *buf, int size) "client-state: %p, buf %p size %d"
Please use "vc %p buf %p size %d" without ':' or ','. Some trace
events have been merged which do not follow the convention but I'd
like to try keeping the output consistent whenever possible.
Stefan