[Qemu-devel] [PATCH-RFC 0/3] qemu: memory barriers in virtio

[Michael S. Tsirkin]

The following fixes a class of long-standing bugs in qemu:
when kvm is enabled, guest might access device structures
in memory while they are updated by qemu on another CPU.
In this scenario, memory barriers are necessary to prevent
host CPU from reordering memory accesses, which might confuse
the guest.

This patch only fixes virtio, but other emulated devices
might have a similar bug. They'll need to be discovered
and addressed case by case.

This is still under test ... meanwhile: any early feedback/flames?

-- 
MST


Michael S. Tsirkin (3):
  qemu: add barriers.h header
  virtio: use a real wmb
  virtio: add missing barriers

 hw/barriers.h |  131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio.c   |   18 ++++----
 2 files changed, 139 insertions(+), 10 deletions(-)
 create mode 100644 hw/barriers.h