On Fri, 8 Jun 2012 17:48:56 +0100 "Daniel P. Berrange" <berra...@redhat.com> wrote:
> On Wed, May 30, 2012 at 03:50:37PM -0300, Luiz Capitulino wrote: > > On Mon, 21 May 2012 17:59:53 +0100 > > "Daniel P. Berrange" <berra...@redhat.com> wrote: > > > > +/* Global, one-time initializer to configure the rate limiting > > > + * and initialize state */ > > > +static void monitor_protocol_event_init(void) > > > +{ > > > + qemu_mutex_init(&monitor_event_state_lock); > > > + /* Limit RTC & BALLOON events to 1 per second */ > > > + monitor_protocol_event_throttle(QEVENT_RTC_CHANGE, 1000); > > > + monitor_protocol_event_throttle(QEVENT_BALLOON_CHANGE, 1000); > > > + monitor_protocol_event_throttle(QEVENT_WATCHDOG, 1000); > > > > What about SUSPENDED and BLOCK_IO_ERROR? Couldn't the former be also > > used by a malicious guest to cause a DoS? The former is already emitted > > several times for virtio. > > This can't be used to filter BLOCK_IO_ERROR, since that event > contains per-device state information. Filtering this would > need to be done in the block layer, so it can done per device. That's right. > I don't think SUSPEND can be used to DoS, since once the VM > is in the suspend state, a monitor command is required to wake > it up again before the guest OS can trigger a new suspend. Can't the guest OS awake itself?