From: Peter Krempa <pkrempa@redhat.com>
To: Laine Stump <laine@redhat.com>
Cc: libvir-list@redhat.com, passt-dev@passt.top
Subject: Re: [libvirt PATCH] qemu: allow passt to self-daemonize
Date: Thu, 9 Feb 2023 09:36:26 +0100 [thread overview]
Message-ID: <Y+SwitLLW89luHBS@angien.pipo.sk> (raw)
In-Reply-To: <20230208231310.1728051-1-laine@redhat.com>
On Wed, Feb 08, 2023 at 18:13:10 -0500, Laine Stump wrote:
> I initially had the passt process being started in an identical
> fashion to the slirp-helper - libvirt was daemonizing the new process
> and recording its pid in a pidfile. The problem with this is that,
> since it is daemonized immediately, any startup error in passt happens
> after the daemonization, and thus isn't seen by libvirt - libvirt
> believes that the process has started successfully and continues on
> its merry way. The result was that sometimes a guest would be started,
> but there would be no passt process for qemu to use for network
> traffic.
>
> Instead, we should be starting passt in the same manner we start
> dnsmasq - we just exec it as normal (along with a request that passt
> create the pidfile, which is just another option on the passt
> commandline) and wait for the child process to exit; passt then has a
> chance to parse its commandline and complete all the setup prior to
> daemonizing itself; if it encounters an error and exits with a non-0
> code, libvirt will see the code and know about the failure. We can
> then grab the output from stderr, log that so the "user" has some idea
> of what went wrong, and then fail the guest startup.
>
> Signed-off-by: Laine Stump <laine@redhat.com>
> ---
> src/qemu/qemu_passt.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
[..]
> if (cmdret < 0 || exitstatus != 0) {
> virReportError(VIR_ERR_INTERNAL_ERROR,
> - _("Could not start 'passt'. exitstatus: %d"), exitstatus);
> + _("Could not start 'passt': %s"), errbuf);
> goto error;
> }
So the 'passt' binary doesn't do any logging later on during runtime
which we'd have to capture into a specific log file?
For this patch:
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
next prev parent reply other threads:[~2023-02-09 8:36 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 23:13 [libvirt PATCH] qemu: allow passt to self-daemonize Laine Stump
2023-02-09 8:36 ` Peter Krempa [this message]
2023-02-09 8:59 ` Michal Prívozník
2023-02-09 9:09 ` Peter Krempa
2023-02-09 10:09 ` Stefano Brivio
2023-02-09 8:48 ` Martin Kletzander
2023-02-09 8:52 ` Michal Prívozník
2023-02-09 9:56 ` Daniel P. Berrangé
2023-02-09 10:10 ` Michal Prívozník
2023-02-09 10:54 ` Stefano Brivio
2023-02-09 10:31 ` Stefano Brivio
2023-02-14 8:01 ` Michal Prívozník
2023-02-14 10:08 ` Stefano Brivio
2023-02-14 11:13 ` Michal Prívozník
2023-02-14 12:29 ` Stefano Brivio
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