This was introduced recently in QEMU, see
https://bugzilla.redhat.com/show_bug.cgi?id=1982165:

  Bus locks disrupts overall performance since it blocks all other cores
  (which must wait for the bus lock to be released before their memory
  operations).

  For VMM, it can detect every bus lock acquired by guest VMs and induces
  a VM exit. So VMM can count the number/frequency of bus lock and take
  some throttling action or just kill the guest.

Tim Wiederhake (5):
  conf: Add bus-lock-ratelimit
  qemu: Add bus-lock-ratelimit
  doc: schema: Add bus-lock-ratelimit to domain schema
  tests: Add tests for bus-lock-ratelimit
  doc: Document new bus-lock-ratelimit option

 docs/formatdomain.rst                     |  4 +++
 docs/schemas/domaincommon.rng             |  7 +++++
 src/conf/domain_conf.c                    | 34 +++++++++++++++++++++++
 src/conf/domain_conf.h                    |  2 ++
 src/qemu/qemu_command.c                   |  4 +++
 src/qemu/qemu_validate.c                  |  1 +
 tests/qemuxml2argvdata/kvm-features.args  |  2 +-
 tests/qemuxml2argvdata/kvm-features.xml   |  1 +
 tests/qemuxml2xmloutdata/kvm-features.xml |  1 +
 9 files changed, 55 insertions(+), 1 deletion(-)

-- 
2.31.1