The Design and Implementation of the Anykernel and Rump Kernels

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A tmpfs server listening on INADDR_ANY port 12765:
$ rump_server -lrumpvfs -lrumpfs_tmpfs tcp://0:12765/
Map 1GB host file dk.img as the block device /dev/dk using etfs, specify local
domain URL using a relative path:
$ rump_allserver -d key=/dev/dk,hostpath=dk.img,size=1g unix://dkserv
A TCP/IP server with the if_virt driver, specify socket using an absolute path:
$ rump_server -lrumpnet -lrumpnet_net -lrumpnet_netinet \
-lrumpnet_virt unix:///tmp/tcpip
Figure 3.34: Example invocations lines of rump_server. All invocations
create rump kernels listening for clients at different addresses with different capabilities.
drivers supported by the server are given as command line arguments and dynamically
loaded by the server. The variant rump_allserver includes all rump kernel
components that were available at the time that the system was built. Figure 3.34
illustrates server usage with examples.
The data transport and protocol layer for remote clients is implemented entirely
within the hypervisor. Because host sockets were used already, those layers were
convenient to implement there. This implementation locus means that the kernel
side of the server and the hypercall layer need to communicate with each other. The
interfaces used for communication are a straightforward extension of the communication
protocol we will discuss in detail next (Section 3.12.4); we will not discuss
the interfaces. The interfaces are defined in sys/rump/include/rump/rumpuser.h
and are implemented in lib/librumpuser/rumpuser_sp.c for the hypervisor and
sys/rump/librump/rumpkern/rump.c for the kernel.