On Tue, Aug 14, 2012 at 05:04:16PM +0300, Avi Kivity wrote: > On 08/14/2012 05:00 PM, Jan Kiszka wrote: > > >>> The host can prevent this by leaving disabling the guest pmu. But > >>> disabling jump labels for real-time kernels may be acceptable too. We > >>> can probably to it at run time by forcing the slow path at all times. > >> Yes, it is possible to add module option that will force slow path if > >> needed. > > > > Should I write a patch or will you? Having host-side stop_machine due to > > such common guest operations is indeed a no-go for RT. > > > > Note that an additional patch is needed for perf, otherwise the guest > (or a user, but that's less of a concern for realtime) can easily invoke > stop_machine by configuring and unconfiguring its pmu. > > Are we talking about malicious guests? Why not compile kernel with jump label disabled if this is serious concern? -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
