On Sun, Feb 28, 2010 at 12:45:07PM +0000, Paul Brook wrote: > > > There certainly > > > exist machines that can change physical RAM mapping. > > > > I am talking about mapping between phy RAM offset and qemu virt address. > > When can it change without RAM in question going away? > > RAM offset or guest physical address? The two are very different.
RAM offset. virtio only cares about where the rings are. > Some machines have chip selects that allow given physical address range to be > mapped to different banks of ram. > > Paul So guest can cause vhost to write to a wrong place in RAM, but it can just pass a wrong address directly. As long as vhost does not access a non-RAM address, we are definitely fine. -- MST