Merge remote-tracking branch 'remotes/awilliam/tags/vfio-update-20180817.0' into staging

VFIO update 2018-08-17

 - Enhance balloon inhibitor for multiple users and use around vfio
   device assignment (Alex Williamson)

# gpg: Signature made Fri 17 Aug 2018 17:43:37 BST
# gpg:                using RSA key 239B9B6E3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>"
# gpg:                 aka "Alex Williamson <alex@shazbot.org>"
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>"
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>"
# Primary key fingerprint: 42F6 C04E 540B D1A9 9E7B  8A90 239B 9B6E 3BB0 8B22

* remotes/awilliam/tags/vfio-update-20180817.0:
  vfio/ccw/pci: Allow devices to opt-in for ballooning
  vfio: Inhibit ballooning based on group attachment to a container
  kvm: Use inhibit to prevent ballooning without synchronous mmu
  balloon: Allow multiple inhibit users

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 351b305e1a..e96bbdc78b 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -349,6 +349,15 @@ static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
         }
     }
 
+    /*
+     * All vfio-ccw devices are believed to operate in a way compatible with
+     * memory ballooning, ie. pages pinned in the host are in the current
+     * working set of the guest driver and therefore never overlap with pages
+     * available to the guest balloon driver.  This needs to be set before
+     * vfio_get_device() for vfio common to handle the balloon inhibitor.
+     */
+    vcdev->vdev.balloon_allowed = true;
+
     if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
         goto out_err;
     }