(kbclient) Client is slow to disconnect

[fbaew]

I posit that this is because it sometimes takes a while to:

• Connect to the monitor relay
• get a response for info usb
• iterate over that response to find our target device

Perhaps it would be better to interrogate info usb immediately after attaching the device to the guest, so we could cache the device ID until we need to disconnect.

[fbaew]

As of commit 9d8b0cd we now cache the device ID a few seconds after connecting it to the guest. This does not appear to improve performance. That rules out the last 2 point above as culprits, so next I'll try maintaining a persistent connection to the management server.

Other possibilities to consider:

• This is a limitation of qemu's usb hotplugging functionality
• This is a side-effect of the way we are triggering the client on Windows (i.e. w/ a Windows shortcut with a defined hotkey.) More analysis/testing will be required to prove or disprove this.