Re: [Qemu-devel] Question: can we hot plug a PCIe switch on machine "virt"

[Michael S. Tsirkin]

On Wed, Apr 03, 2019 at 03:32:09PM +0800, Heyi Guo wrote:
> Hi folks,
> 
> In physical world, a PCIe switch including one upstream port and several 
> downstream ports is a single physical device, however we treat each port as a 
> device in qemu world. In qemu docs/pcie.txt, we have below statements:
> 
> Line 230: Be aware that PCI Express Downstream Ports can't be hot-plugged into
> Line 231: an existing PCI Express Upstream Port.
> 
> To my understanding, it implies PCIe downstream ports *can* be hot-plugged 
> into something which is not an existing upstream port. If it is true, how can 
> we do that? AFAIK monitor command device_add can only add one device at a 
> time.
> 
> Please help to show the truth.
> 
> Thanks,
> 
> Heyi
> 

afaik they can only be plugged into upstearm ports with or without hotplug.

-- 
mst