Re: [Qemu-devel] [RFC v2 05/38] plugin: add user-facing API

[Aaron Lindsay]

On Dec 14 12:50, Emilio G. Cota wrote:
> On Fri, Dec 14, 2018 at 12:08:22 -0500, Emilio G. Cota wrote:
> > On Fri, Dec 14, 2018 at 15:57:32 +0000, Aaron Lindsay wrote:
> (snip)
> > > I added a function to the user-facing plugin API in my own version of
> > > Pavel's plugin patchset to clear all existing plugin instrumentation,
> (snip)
> > I think the following API call would do what you need:
> > 
> >   typedef int (*qemu_plugin_reset_cb_t)(qemu_plugin_id_t id);
> >   void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_reset_cb_t cb);
> > 
> > (or maybe qemu_plugin_reinstall?)
> 
> An alternative is to track the TBs that a plugin has inserted
> instrumentation into, and only flush those. This would require
> us to do an additional hash table insert when adding a
> direct callback, but it allow us to avoid exporting tb_flush indirectly
> to plugins, which could be abused by malicious plugins to perform
> a DoS attack.

I don't think I have a preference. Though now I'm curious - when/why do
you expect users might run plugins that could be malicious in this way?

-Aaron