Windows 10 HVM with PCI devices does not boot

Hello!

If I attach PCI devices (2 USB controllers) to my Windows 10 standalone HVM it fails to boot with error:

Booting from Hard Disk…
Boot failed: could not read the boot disk

No bootable device.

How can I fix this? Is this a known issue?

Background: goal is to back up an iPhone. On R4.0 I succesfully used a Windows 10 VM with attached USB controllers (via qube settings/PCI devices). Now I tried to recreate this on R4.1.1. Installing new Windows 10 standalone VMs and Qubes Windows Tools according to the official guides worked great. But when I attach a PCI device I get the above error.

Further details: the error occurs for Windows 10 VMs with and without QWT installed. If I remove the USB controllers from the VMs they boot just fine. Same error also occurs with an old Windows 7 standalone VM. Strict PCI reset is disabled.

Thanks for any thoughts!

I have found a solution: setting the Windows 10 VMs RAM to 3500MB. Now it boots fine, with the USB controllers attached.

After coming across the issue below I tried lowering the VMs RAM:

For me, 3500MB turned out to be the limit. With more RAM, I got the ‘no bootable device’ error. Initially I had the Windows 10 VM set to use 6GB.

Great. Please mark your post as a solution so it could help other users too.