Re: Failure of hot plugging secondary virtio_blk into q35 Windows 2019

[Annie.li]

Update:

I've tested q35 guest w/o OVMF, the APCI PCI hot-plugging works well in 
q35 guest. Seems this issue only happens in q35 guest w/ OVMF.

Looks that there is already a bug filed against this hotplug issue in 
q35 guest w/ OVMF,

https://bugzilla.redhat.com/show_bug.cgi?id=2004829

In this bug, it is recommended to add "-global 
ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off \" on qemu command for 
6.1. However, with this option for 6.1(PCIe native hotplug), there still 
are kinds of issues. For example, one of them is the deleted virtio_blk 
device still shows in the Device Manager in Windows q35 guest, the 
operation of re-scanning new hardware takes forever there. This means 
both PCIe native hotplug and ACPI hotplug all have issues in q35 guests.

Per comments in this bug, changes in both OVMF and QEMU are necessary to 
support ACPI hot plug in q35 guest. The fixes may likely be available in 
QEMU 6.2.0. I am wondering if  someone is already working on this?

Thanks

Annie