On 21/02/2019 00:39, Marek Marczykowski-Górecki wrote: > On Wed, Feb 20, 2019 at 08:15:30PM +0000, Joao Martins wrote: >> 2. PV Driver support (patches 17 - 39) >> >> We start by redirecting hypercalls from the backend to routines >> which emulate the behaviour that PV backends expect i.e. grant >> table and interdomain events. Next, we add support for late >> initialization of xenbus, followed by implementing >> frontend/backend communication mechanisms (i.e. grant tables and >> interdomain event channels). Finally, introduce xen-shim.ko, >> which will setup a limited Xen environment. This uses the added >> functionality of Xen specific shared memory (grant tables) and >> notifications (event channels). > > Does it mean backends could be run in another guest, similarly as on > real Xen? AFAIK virtio doesn't allow that as virtio backends need > arbitrary write access to guest memory. But grant tables provide enough > abstraction to do that safely. As long as the grant table emulation in xen-shim isn't just a wrapper to "normal" KVM guest memory access. I guess the xen-shim implementation doesn't support the same kind of guest memory isolation as Xen does? Juergen
