Current support for bus master (clearing OK bit) together with the need to
support guests which do not enable PCI bus mastering, leads to extra state in
VIRTIO_PCI_FLAG_BUS_MASTER_BUG bit, which isn't robust in case of cross-version
migration for the case when guests use the device before setting DRIVER_OK.
Rip out this code, and replace it:
- Modern QEMU doesn't need VIRTIO_PCI_FLAG_BUS_MASTER_BUG
so just drop it for latest machine type.
- For compat machine types, set PCI_COMMAND if DRIVER_OK
is set.
As this is needed for 2.1 for both pc and ppc, move PC_COMPAT macros from pc.h
to a new common header.
Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
68a27b208a