| Message ID | 20191115161338.42864-3-slp@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | docs/microvm.rst: fix alignment and explain shut down | expand |
On 15/11/19 17:13, Sergio Lopez wrote: > Add a new section explaining the particularities of the microvm > machine type for triggering a guest-initiated shut down. > > Signed-off-by: Sergio Lopez <slp@redhat.com> > --- > docs/microvm.rst | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/docs/microvm.rst b/docs/microvm.rst > index 4cf84746b9..fcf41fc1f6 100644 > --- a/docs/microvm.rst > +++ b/docs/microvm.rst > @@ -106,3 +106,24 @@ disabled:: > -device virtio-blk-device,drive=test \ > -netdev tap,id=tap0,script=no,downscript=no \ > -device virtio-net-device,netdev=tap0 > + > + > +Triggering a guest-initiated shut down > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +As the microvm machine type includes just a small set of system > +devices, some x86 mechanisms for rebooting or shutting down the > +system, like sending a key sequence to the keyboard or writing to an > +ACPI register, doesn't have any effect in the VM. > + > +The recommended way to trigger a guest-initiated shut down is by > +generating a ``triple-fault``, which will cause the VM to initiate a > +reboot. Additionally, if the ``-no-reboot`` argument is present in the > +command line, QEMU will detect this event and terminate its own > +execution gracefully. > + > +Linux does support this mechanism, but by default will only be used > +after other options have been tried and failed, causing the reboot to > +be delayed by a small number of seconds. It's possible to instruct it > +to try the triple-fault mechanism first, by adding ``reboot=t`` to the > +kernel's command line. > Queued, thanks. Paolo
diff --git a/docs/microvm.rst b/docs/microvm.rst index 4cf84746b9..fcf41fc1f6 100644 --- a/docs/microvm.rst +++ b/docs/microvm.rst @@ -106,3 +106,24 @@ disabled:: -device virtio-blk-device,drive=test \ -netdev tap,id=tap0,script=no,downscript=no \ -device virtio-net-device,netdev=tap0 + + +Triggering a guest-initiated shut down +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +As the microvm machine type includes just a small set of system +devices, some x86 mechanisms for rebooting or shutting down the +system, like sending a key sequence to the keyboard or writing to an +ACPI register, doesn't have any effect in the VM. + +The recommended way to trigger a guest-initiated shut down is by +generating a ``triple-fault``, which will cause the VM to initiate a +reboot. Additionally, if the ``-no-reboot`` argument is present in the +command line, QEMU will detect this event and terminate its own +execution gracefully. + +Linux does support this mechanism, but by default will only be used +after other options have been tried and failed, causing the reboot to +be delayed by a small number of seconds. It's possible to instruct it +to try the triple-fault mechanism first, by adding ``reboot=t`` to the +kernel's command line.
Add a new section explaining the particularities of the microvm machine type for triggering a guest-initiated shut down. Signed-off-by: Sergio Lopez <slp@redhat.com> --- docs/microvm.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)