DragonFly users List (threaded) for 2006-10
Re: Xen vs VMware
:Possibly offtopic for this thread, but:
:Will the approach your taking with DragonFly allow for quickly and
:easily migrating the virtualized kernels between machines?
:Also, what about the possibility of running your userland kernels
:under other operating systems? One of the advantages that Xen and
:VMWare has is that you CAN run multiple operating systems when you are
I think its possible, but those other operating systems would still
have to implement the virtualization system calls and mmap support.
It isn't possible to run a kernel as a userland process without them
because the kernel would not be able to manage the VM spaces for
its own 'user' processes (from the point of view of the virtual kernel).
It would be possible to make this into a defacto standard. The actual
work involved isn't all that great... the hard part is switching
between VM spaces and managing the execution contexts... which is the
part I'm working on now.
* Implement specialized mmap() operations that allow manipulation
of managed VM spaces instead of the calling process's VM space.
* Implement switching to the calling process's VM space (in order
to run a managed VM space), then switching back if a signal
ocurs or the managed VM space takes a page-fault, trap, or
makes a system call. NOT DONE.
* Implement a build for the virtualized kernel itself that
links into a standard user program binary, plus drivers
that emulate network, disk, and other resources. NOT DONE.