dma: eliminate DMAContext

The DMAContext is a simple pointer to an AddressSpace that is now always
already available.  Make everyone hold the address space directly,
and clean up the DMA API to use the AddressSpace directly.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory: give name to every AddressSpace

The "info mtree" command in QEMU console prints only "memory" and "I/O"
address spaces while there are actually a lot more other AddressSpace
structs created by PCI and VIO devices. Those devices do not normally
have names and therefore not present in "info mtree" output.

The patch fixes this.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory: Fix comment typo

s/ajacent/adjacent

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory: as_update_topology_pass: Improve comments

These comments were a little difficult to read. First one had
incorrect parenthesis. The part about attributes changing is
really applicable to the region being 'in both' rather than 'in
new'

Second comment has an obscure parenthetic about 'Logging may have
changed'. Made clearer, as this if is supposed to handle the case where
the memory region is unchanged (with the notable exception re logging).

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory: render_memory_region: factor out fr constant setters

These 4 replicated lines set properties of fr that are constant over
the course of the function. Factor out their repeated setting (and also
guards against them being set multiple times in the loop below).

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>