linux-kernel - Re: [PATCH] virtio_console: Add support for multiple ports for generic guest and host communication

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200909221214.04340.rusty@rustcorp.com.au>
Date:	Tue, 22 Sep 2009 12:14:04 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	Alan Cox <alan@...ux.intel.com>
Cc:	Amit Shah <amit.shah@...hat.com>,
	virtualization@...ts.linux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] virtio_console: Add support for multiple ports for generic guest and host communication

On Sat, 12 Sep 2009 01:30:10 am Alan Cox wrote:
> > The interface presented to guest userspace is of a simple char
> > device, so it can be used like this:
> > 
> >     fd = open("/dev/vcon2", O_RDWR);
> >     ret = read(fd, buf, 100);
> >     ret = write(fd, string, strlen(string));
> > 
> > Each port is to be assigned a unique function, for example, the
> > first 4 ports may be reserved for libvirt usage, the next 4 for
> > generic streaming data and so on. This port-function mapping
> > isn't finalised yet.
> 
> Unless I am missing something this looks completely bonkers
> 
> Every time we have a table of numbers for functionality it ends in
> tears. We have to keep tables up to date and managed, we have to
> administer the magical number to name space.

The number comes from the ABI; we need some identifier for the different
ports.  Amit started using names, and I said "just use numbers"; they have
to be documented and agreed by all clients anyway.

ie. the host says "here's a port id 7", which might be the cut & paste
port or whatever.

Cheers,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/