[Qemu-devel] register_savevm()

[Catalin Vasile]

When are save() and load() handlers actually used?
When are they trying to save and restore state?

Re: [Qemu-devel] register_savevm()

[Peter Maydell]

On 17 April 2015 at 14:03, Catalin Vasile  wrote:
> When are save() and load() handlers actually used?
> When are they trying to save and restore state?

These are used for:
 * live migration
 * VM state save/load (eg via monitor 'savevm' and 'loadvm'
commands or command line -loadvm option).

Note that the register_savevm() function is legacy and should
not be used in any new code. Devices should use VMStateDescription
structs instead.

-- PMM

Re: [Qemu-devel] register_savevm()

[Catalin Vasile]

Does loadvm create new virtual devices (dev.init(), dev.realize(), etc.)
for the vm to run onto and then load VMStateDescription?

On Fri, Apr 17, 2015 at 4:40 PM, Peter Maydell 
wrote:

> On 17 April 2015 at 14:03, Catalin Vasile 
> wrote:
> > When are save() and load() handlers actually used?
> > When are they trying to save and restore state?
>
> These are used for:
>  * live migration
>  * VM state save/load (eg via monitor 'savevm' and 'loadvm'
> commands or command line -loadvm option).
>
> Note that the register_savevm() function is legacy and should
> not be used in any new code. Devices should use VMStateDescription
> structs instead.
>
> -- PMM
>

Re: [Qemu-devel] register_savevm()

[Peter Maydell]

On 17 April 2015 at 14:54, Catalin Vasile  wrote:
> Does loadvm create new virtual devices (dev.init(), dev.realize(), etc.) for
> the vm to run onto and then load VMStateDescription?

loadvm itself does not, no. You have to start QEMU with the
exact same configuration and command line options, which
means the usual startup will create all the devices and
connect them up. Then you can do a loadvm which will read
the state into all the existing devices.

-- PMM