Re: [PATCH V2] Add a new PIIX option to control PCI hot unplugging of devices on non-root buses

[Ani Sinha]

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Accidental? So maybe what you need is actually something else then -

avoid *removing* the device when it's powered down.

You don’t get it. It is not hypervisor admins who are unplugging it. It is the end users. Even RedHat customers want this feature. See following resources:
https://www.redhat.com/archives/libvir-list/2020-February/msg00110.html
https://bugzilla.redhat.com/show_bug.cgi?id=1802592
https://bugzilla.redhat.com/show_bug.cgi?id=1790899

My approach is much more fine grained than just disable everything approach that we have for q35. For i440fx we can do better than that

By the way, here's another glaring feature disparity between i440fx and q35 which we perhaps did not debate with as much fervour and push back as we debated here. When we implemented per slot hotplug disable for PCIE, we ignored to implement the same per slot capability for conventional PCI. Why was feature disparity across two machine types wasn't so much of an issue then? 

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MST