> USB sucks. PCIe is great. > This is the same problem any kind of USB virtualization/network tunnelling has. +1. I've been using QubesOS on my workstation f

> USB sucks. PCIe is great. > This is the same problem any kind of USB virtualization/network tunnelling has. +1. I've been using QubesOS on my workstation for a while, and I found the problem associated with USB virtualization/tunnelling also has a major impact on QubesOS's usability (USBility?). Long story short, QubesOS's security model depends on the ability to isolate individual peripherals at the hypervisor level. For PCI-E it's easy, but for USB it's a headache. It has various security, compatibility and performance problems. If one has ever encountered such a problem, the only workaround is assigning an entire EHCI or xHCI USB host controller at the PCI-E level to a VM, and this is only feasible on machines with multiple USB controllers. > I wrote the QEMU virtual xHCI code and the original prototype, which ignored the QEMU USB subsystem and passed through straight to the host, worked very well I also got the idea to build something similar, but in hardware - put 4 individual PCI-E USB host controllers behind a PCI-E switch, so that each USB port can be seen as an individual PCI-E device. Now the USB problem in Qubes is solved forever...