Pull request

This includes the atomic_ -> qatomic_ rename that touches many files and is
prone to conflicts.

Pull request

v2:
 * Rebased after meson and resolved conflict in "softmmu: Add missing trace-events file"
 * Dropped "meson: Don't make object files for dtrace on macOS" (already merged via Paolo's tree)

Block pull request for testing

Peter hit a virtio-blk-test failure caused by the new DISCARD/WRITE_ZEROES
patches that Stefano and I have been unable to reproduce.  Here are the patches
so they can be tested again in Peter's environment.

Pull request

Pull request

Pull request