[Qemu-devel] [PATCH 0/3] exec: Collect CPU's AddressSpace info into its own struct

[Peter Maydell]

This patchset is a bit of groundwork heading in the direction
of supporting multiple AddressSpaces per CPU. It does actually
do something useful (handle a FIXME remark in tcg_commit()) so
I've put it out for that reason and for some early comments.

Patch 1 is just removing an unnecessary call to cpu_reload_memory_map()
to make the cleanup a bit easier.
Patch 2 is a comment change which I hope Paolo will review to tell
me if I've misunderstood things :-)
Patch 3 is the actual work here: we collect up the fields that
were directly in CPUState but relating to our one-and-only
AddressSpace, and put them in a new struct CPUAddressSpace
CPUState now has a pointer to an array of these (with only one
entry for now). The rearrangement lets us fix the tcg_commit()
FIXME remark by going directly to the affected CPUState from
the MemoryListener pointer rather than having to search all CPUs
for it.

CPUState::as remains, as a convenience pointer to the first
AddressSpace we know about for the benefit of all the targets
which only have one AS per CPU.

The plan here for where to go next is to support calling
tcg_cpu_address_space_init() more than once (in which case
it will add entries to the array), and then update the places
which currently hardcode cpu->cpu_ases[0] to pick the entry
in the array based on a target-cpu hook to convert MemoryAttributes
into an address space index.

I also need to think a bit harder about how KVM will fit into
this, and exactly where we call tcg_cpu_address_space_init().
(Current thought is that should be from the cpu object's
realize function, based on QOM properties for allowing the board
to register the AddressSpaces with the CPU.)

Peter Maydell (3):
  exec.c: Don't call cpu_reload_memory_map() from cpu_exec_init()
  cpu-exec.c: Clarify comment about cpu_reload_memory_map()'s RCU
    operations
  exec.c: Collect AddressSpace related fields into a CPUAddressSpace
    struct

 cpu-exec.c              | 33 ++++++++++++++--------------
 exec.c                  | 57 ++++++++++++++++++++++++++++++++-----------------
 include/exec/exec-all.h |  2 +-
 include/qemu/typedefs.h |  1 +
 include/qom/cpu.h       |  7 ++++--
 5 files changed, 62 insertions(+), 38 deletions(-)

-- 
1.9.1