[PATCH v3 0/9] Many improvements to HVF memory-related codes

[Yan-Jie Wang]

changes in v3:
* Fix last two patches which contain mistakes:
 - hvf: only consider directly writeable memory regions for
    dirty-tracking
 - hvf: remove the need to lookup memory slots when clearing dirty-bits

changes in v2:
* Rebase to the current master.
* Correct a mistake in "hvf: simplify data structures and codes of
  memory related functions" patch
* add two patches for HVF memory listener. The changes are
 - only consider directly writeable memory regions for dirty-tracking
 - in `hvf_log_clear`, use provided `section` (MemoryRegionSection)
   from the caller to determine the pages that need to write-protected
   instead of calling hvf_set_dirty_tracking to write-protect the memory
   slots that contains the pages whose dirty-bits are cleared.

----------

I recently bought a Mac with M1 Pro chip, and use QEMU to setup a Linux
virtual machine.  QEMU crashed when I started a VM with HVF accelerator
enabled and with the device, bochs-display, added.

After digging into the source code, I found that dirty-tracking in HVF
did not work properly, which made QEMU crashed. Therefore I made this
series of patches to fix the problem.

Followings are the summary of the changes that these patches make:
 1. Move HVF memory-related functions and codes into a new file
    hvf-mem.c
 2. Simplify the logics of adding and removing memory regions in HVF
    memory listener
 3. Fix HVF dirty-tracking logics for both Intel and Apple Silicon Macs
 4. Use GTree and dynamically-allocated structures to store HVF memory
    slots instead of fixed-size arrays. This makes memory slots more
    scalable. It is inspired by the recent changes in Linux kernel
    (v5.17) that use red-black trees instead of arrays to store
    in-kernel KVM memory slots.
 5. Add a lock to protect the data structures of HVF memory slots

Patches have been tested on Apple Silicon Macs and Intel Macs.

Yan-Jie Wang (9):
  hvf: move memory related functions from hvf-accel-ops.c to hvf-mem.c
  hvf: simplify data structures and codes of memory related functions
  hvf: use correct data types for addresses in memory related functions
  hvf: rename struct hvf_slot to HVFSlot
  hvf: fix memory dirty-tracking
  hvf: add a lock for memory related functions
  hvf: use GTree to store memory slots instead of fixed-size array
  hvf: only consider directly writeable memory regions for
    dirty-tracking
  hvf: remove the need to lookup memory slots when clearing dirty-bits

 accel/hvf/hvf-accel-ops.c | 221 +-----------------------
 accel/hvf/hvf-mem.c       | 343 ++++++++++++++++++++++++++++++++++++++
 accel/hvf/meson.build     |   1 +
 include/sysemu/hvf_int.h  |  18 +-
 target/arm/hvf/hvf.c      |   5 +
 target/i386/hvf/hvf.c     |  25 +--
 6 files changed, 359 insertions(+), 254 deletions(-)
 create mode 100644 accel/hvf/hvf-mem.c

-- 
2.32.0 (Apple Git-132)