From: Steven Rostedt <email@example.com>
To: Eric Blake <firstname.lastname@example.org>
Cc: Stefan Hajnoczi <email@example.com>,
firstname.lastname@example.org, Stefan Hajnoczi <email@example.com>,
Luiz Capitulino <firstname.lastname@example.org>,
Subject: Re: [Qemu-devel] [RFC] host and guest kernel trace merging
Date: Mon, 7 Mar 2016 11:26:27 -0500 [thread overview]
Message-ID: <email@example.com> (raw)
On Mon, 7 Mar 2016 09:10:10 -0700
Eric Blake <firstname.lastname@example.org> wrote:
> On 03/07/2016 08:49 AM, Steven Rostedt wrote:
> > On Mon, 7 Mar 2016 15:17:05 +0000
> > Stefan Hajnoczi <email@example.com> wrote:
> >> qemu-guest-agent runs inside the guest and replies to RPC commands from
> >> the host. It is used for backups, shutdown, network configuration, etc.
> >> From time to time people have wanted the ability to execute an arbitrary
> >> command inside the guest and return the output. This functionality has
> >> never been merged, probably for the security reason.
> > How's the connection set up. That is, how does it know the commands are
> > coming from the host? And how does it know that the commands from the
> > host is from a trusted source? If the host is compromised, is there
> > anything keeping an intruder from controlling the guest?
> qemu-guest-agent uses a virtio channel, so only the host can be driving
> that channel. But how can a guest know that it trusts the host? It
> can't. A compromised host implicitly compromises all guests, and that's
> always been the case. At least qemu-guest-agent doesn't make the window
> any larger.
I should have been a bit more clear about what I meant by "host is
compromised". I should have asked, what about untrusted tasks on the
host. Is the channel protected where only admin users can access it?
Of course, one of my concerns with the trace-cmd server is that it may
require a network connection, because doesn't a virtio channel require
to be initialized at boot up? Where the host must have an active
listener when the guest starts? Or am I thinking about something else.
prev parent reply other threads:[~2016-03-07 16:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <firstname.lastname@example.org>
[not found] ` <20160304111933.GB626@stefanha-x1.localdomain>
2016-03-04 13:23 ` [Qemu-devel] [RFC] host and guest kernel trace merging Steven Rostedt
[not found] ` <20160307151705.GD20937@stefanha-x1.localdomain>
2016-03-07 15:49 ` Steven Rostedt
[not found] ` <56DDA7E2.email@example.com>
2016-03-07 16:26 ` Steven Rostedt [this message]
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