Re: [Qemu-devel] [Qemu-discuss] qemu-kvm: -netdev user: Parameter 'id' is missing

[anatoly techtonik <techtonik@gmail.com>]

On Tue, Jul 24, 2012 at 1:23 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> On Mon, Jul 23, 2012 at 10:41 PM, anatoly techtonik <techtonik@gmail.com> wrote:
>> Forwarding per discussion in qemu-discuss.
>> Please CC.
>>
>> ---------- Forwarded message ----------
>> From: Mike Lovell <mike@dev-zero.net>
>> Date: Mon, Jul 23, 2012 at 10:58 PM
>> Subject: Re: [Qemu-discuss] qemu-kvm: -netdev user: Parameter 'id' is missing
>> To: qemu-discuss@nongnu.org
>>
>>
>> On 07/20/2012 04:10 PM, anatoly techtonik wrote:
>>>
>>> The documentation at http://wiki.qemu.org/Documentation/Networking
>>> makes people think that 'id' parameter for -netdev user is optional,
>>> which doesn't appear to be true:
>>>
>>>      $ qemu-kvm -hda image.img -netdev user
>>>      qemu-kvm: -netdev user: Parameter 'id' is missing
>
> I have updated the wiki page.

Even with -net nic considered obsolete (is the whole -net family
obsolete?), it looks like there is no complete replacement for it. For
example, there is no equivalent for -net nic,model=? (referenced from
wiki). It is also strange to read proposal to "see the qemu man page
for the various options that you can pass to -net nic". Unfortunately,
-netdev is completely undocumented in man and there is no info that
-net nic and -net user are obsolete there. All this stuff is
confusing.

> A -netdev needs to be paired with a NIC -device.  That's why the
> identifier is essential, it allows you to say -netdev
> <type>,id=netdev0 -device <type>,netdev=netdev0.

It still says "The id option can be used with the -device...", where
"can be" looks like it should be replaced by "must".

Why is it impossible for -netdev to create NIC device automatically if
not explicitly set? As a user I don't really know which net device do
I need. This would greatly simplify user experience (and lower Qemu
bounce rate).

There is also a question about user mode. It is said "the guest is not
directly accessible from the host or the external network" and also
"You can isolate the guest from the host (and broader network) using
the restrict option". ??? Guest is already not directly accessible -
why use the restrict?
--
anatoly t.