[Qemu-devel] Re: QEMU as a "virtual smart card"?

[Paolo Bonzini <pbonzini@redhat.com>]

> At least looking naively at QEMU, it seems that its CPU and RAM are
> well protected from the host operating system--in a way to say make it
> practically impossible for some malware to extract the secret key used
> in a virtual machine.

I don't understand: the host operating system, by definition, can see 
everything.  A privileged process (i.e. running as root) can always look 
at /dev/mem and read info about QEMU's CPU and RAM.

> We are also interested in the isolation of input devices, in
> particularly the keyboard as to prevent PIN sniffing.  My "naive"
> impression is that key logging for a PS/2 keyboard is probably more
> difficult than with a USB keyboard.  Is there any thruth to my
> misconception?

If you mean by cracking the keyboard itself, USB keyboards have a 
firmware while PS/2 keyboards have only some glue logic, so I'd tend to 
agree.  For PS/2 you would need physical access to the cable, after 
which all hopes are off anyway.  For software attacks (i.e. in the OS) I 
don't think there is any difference.

> * Is there any way of getting exclusive access to an USB pen drive
> from a virtual machine, preventing the host operating system to say take
> an image of the content?

Again, not if the attacker can run privileged processes on the host.

Paolo