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Re: [Qemu-discuss] Longer time to detach device in q35
From: |
Maxim Levitsky |
Subject: |
Re: [Qemu-discuss] Longer time to detach device in q35 |
Date: |
Sun, 28 Apr 2019 14:20:44 +0300 |
I 'think' that this is due to the fact that Q35 uses the PCIe hotplug, which was
done for real life PCIe hotplug which involves operator pressing a button, and
then waiting for confirmation.
The spec allows the operator to change his mind during 5 second timeout (or
something similiar).
Now what qemu does on hot unplug, is that it presses that button logically, but
then the guest waits the 5 seconds before it acts upon it as written in the
spec.
The 'pc' machine either uses acpi or older 'standard pci hotplug controller'
whic might lack this 'feature'
I am adding Michael here, as I remember that he mentioned this once.
Best regards,
Maxim Levitsky