How can I boot from a disk attached to a HBA that is passed through to the guest?

[swoy]

I know this can be done in unRAID, but I cannot find any documentation that guides me to how I can boot the guest OS from a drive attached to a HBA card I have passed through to the guest. Is this possible in Proxmox? Can someone point me to any documentation that can shed some light on this?

 

[swoy]

As it turns out, I had to set the following settings on the PCI Device:
All functions: Enables
ROM-Bar: Enabled
PCI-Express: Enabled
Primary GPU: Disabled

For some reason, trying this when using Spice doesn't work. When I passthrough a GPU and set Display to "none" it works. Any idea why?