Re: [Qemu-devel] [PATCH] mark nic as trusted

[Anthony Liguori <anthony@codemonkey.ws>]

Jamie Lokier wrote:
> Anthony Liguori wrote:
>   
>> Are we going to have a standard way of doing this in Linux distros such 
>> that these nics are treated differently from other nics?  Have we gotten 
>> the appropriate distro folks to agree to this?
>>     
>
> That wouldn't work for older distros and Windows anyway.  But you
> might reasonably want to run apps doing guest-host communication on
> older guest distros too, simply as an app, not requiring guest
> customisation.
>   

That's probably going to be difficult.

> Is there some way to mark a PCI device so it will be ignored at boot
> time generically?

No.

>   Changing the PCI ID will do that for all guests,
> but is it then feasible for the vmchannel guest admin software to bind
> a NIC driver to a non-standard PCI ID, on the major OSes?
>   

I don't see how changing the PCI ID (I presume you mean vendor/device 
ID?) would help.

> Suppose you start a guest with two "trusted" nics, because you want to
> run two unrelated vmchannel-using admin apps.  How does each app know
> which nic to use - or do they share it?
>   

Unrelated vmchannel apps will use different ports on the same nic.  
There will only ever be one trusted nic.

> As the guest OS's TCP is being used, what do you do about IP address
> space conflicts?
>   

The user can choose what address is used for the host.

> Perhaps vmchannel will only use IPv6, so it can confidently pick a
> unique link-local address?
>   

slirp only supports IPv4.

Regards,

Anthony Liguori

> -- Jamie
>
>
>