[Qemu-devel] Virtio device "exit" function

[Qemu-devel] Virtio device "exit" function

[Chris Johnson]

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Hello,

I am working on adding a virtio device to support a PCIe card (PCIe 
pass-through wasn't an option). I need to do some cleanup when a VM that 
is using this device is shutdown. It doesn't seem like the 
device_unrealize function runs on shutdown unlike the device_realize 
function that runs when the VM is started. I've been tracing through 
other virtio device code to try and figure out what "exit" type 
functions will run for other devices when a VM is shutdown but haven't 
had any luck with that yet.

When does a virtio device's unrealize function run?

What function, if any, runs for a virtio device when a VM is shutdown?

Regards,
Chris

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Re: [Qemu-devel] Virtio device "exit" function

[Stefan Hajnoczi]

On Wed, Sep 23, 2015 at 04:32:00PM +0000, Chris Johnson wrote:
> I am working on adding a virtio device to support a PCIe card (PCIe
> pass-through wasn't an option). I need to do some cleanup when a VM that is
> using this device is shutdown. It doesn't seem like the device_unrealize
> function runs on shutdown unlike the device_realize function that runs when
> the VM is started. I've been tracing through other virtio device code to try
> and figure out what "exit" type functions will run for other devices when a
> VM is shutdown but haven't had any luck with that yet.
> 
> When does a virtio device's unrealize function run?
> 
> What function, if any, runs for a virtio device when a VM is shutdown?

When QEMU terminates in vl.c:main(), devices are not unrealized.

The unrealize code is only invoked on hot unplug (e.g. PCI card removed
via 'device_del' command).

What are you trying to do in the unrealize function?

Stefan