On Tue, Nov 20, 2012 at 07:33:49PM -0200, Marcelo Tosatti wrote: > On Tue, Nov 20, 2012 at 06:09:48PM +0800, Hu Tao wrote: > > Hi Marcelo, > > > > On Tue, Nov 13, 2012 at 12:19:08AM -0200, Marcelo Tosatti wrote: > > > On Fri, Nov 09, 2012 at 03:17:39PM -0500, Sasha Levin wrote: > > > > On Mon, Nov 5, 2012 at 8:58 PM, Hu Tao <hutao@xxxxxxxxxxxxxx> wrote: > > > > > But in the case of panic notification, more dependency means more > > > > > chances of failure of panic notification. Say, if we use a virtio device > > > > > to do panic notification, then we will fail if: virtio itself has > > > > > problems, virtio for some reason can't be deployed(neither built-in or > > > > > as a module), or guest doesn't support virtio, etc. > > > > > > > > Add polling to your virtio device. If it didn't notify of a panic but > > > > taking more than 20 sec to answer your poll request you can assume > > > > it's dead. > > > > > > > > Actually, just use virtio-serial and something in userspace on the guest. > > > > > > They want the guest to stop, so a memory dump can be taken by management > > > interface. > > > > > > Hu Tao, lets assume port I/O is the preferred method for communication. > > > > Okey. > > > > > Now, the following comments have still not been addressed: > > > > > > 1) Lifecycle of the stopped guest and interaction with other stopped > > > states in QEMU. > > > > Patch 3 already deals with run state transitions. But in case I'm > > missing something, could you be more specific? > > - What are the possibilities during migration? Say: > - migration starts. > - guest panics. > - migration starts vm on other side? > - Guest stopped due to EIO. > - guest vcpuN panics, VMEXIT but still outside QEMU. > - QEMU EIO error, stop vm. > - guest vcpuN completes, processes IO exit. > - system_reset due to panic. > - Add all possibilities that should be verified (that is, interaction > of this feature with other stopped states in QEMU). > BTW I do remember getting asserts while using breakpoints via gdbstub and stop/cont from the monitor. > --- > > - What happens if the guest has reboot-on-panic configured? Does it take > precedence over hypervisor notification? > > > > Out of curiosity, does kexec support memory dumping? > > > > 2) Format of the interface for other architectures (you can choose > > > a different KVM supported architecture and write an example). > > > > > > 3) Clear/documented management interface for the feature. > > > > It is documented in patch 0: Documentation/virtual/kvm/pv_event.txt. > > Does it need to be improved? > > This is documentation for the host<->guest interface. There is no > documentation on the interface for management. -- 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
