[Qemu-devel] [PATCH RFC 0/5] making address spaces 64 bit wide

[Michael S. Tsirkin]

At the moment, exec ignores high bits in each address,
for efficiency.
This is incorrect: devices can do full 64 bit DMA, it's
only the CPU that is limited by target address space.
Using full 64 bit addresses was clocked at 12% performance
hit on a microbenchmark.
To solve, teach pagetables to skip bits at any level
and not just the lowest level.

This should solve the performance problem (only one line
of code changed on the data path).
I'm still trying to figure out how to measure speed
properly with TCG, sending this out for early feedback and flames.

Michael S. Tsirkin (3):
  exec: relace leaf with skip
  exec: extend skip field to 3 bits
  exec: memory radix tree page level compression

Paolo Bonzini (2):
  split definitions for exec.c and translate-all.c radix trees
  exec: make address spaces 64-bit wide

 translate-all.h |   7 ----
 exec.c          | 117 +++++++++++++++++++++++++++++++++++++++++++++++---------
 translate-all.c |  32 +++++++++-------
 3 files changed, 117 insertions(+), 39 deletions(-)

-- 
MST