vfio/pci: Enable AtomicOps completers on root ports

Dynamically enable Atomic Ops completer support around realize/exit of
vfio-pci devices reporting host support for these accesses and adhering
to a minimal configuration standard.  While the Atomic Ops completer
bits in the root port device capabilities2 register are read-only, the
PCIe spec does allow RO bits to change to reflect hardware state.  We
take advantage of that here around the realize and exit functions of
the vfio-pci device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Robin Voetter <robin@streamhpc.com>
Tested-by: Robin Voetter <robin@streamhpc.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 2674476d6c..a2771b9ff3 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -174,6 +174,7 @@ struct VFIOPCIDevice {
     bool no_vfio_ioeventfd;
     bool enable_ramfb;
     bool defer_kvm_irq_routing;
+    bool clear_parent_atomics_on_exit;
     VFIODisplay *dpy;
     Notifier irqchip_change_notifier;
 };