a...@linux.vnet.ibm.com wrote:
Here are the corresponding changes to the Linux virtio driver...
virtio: Add memory statistics reporting to the balloon driver
When using ballooning to manage overcommitted memory on a host, a system for
guests to communicate their memory usage to the host can provide information
that will minimize the impact of ballooning on the guests. The current
method
employs a daemon running in each guest that communicates memory statistics
to a
host daemon at a specified time interval. The host daemon aggregates this
information and inflates and/or deflates balloons according to the level of
host memory pressure. This approach is effective but overly complex since a
daemon must be installed inside each guest and coordinated to communicate
with
the host. A simpler approach is to collect memory statistics in the virtio
balloon driver and communicate them to the host via the device config space.
This patch enables the guest-side support by adding stats collection and
reporting to the virtio balloon driver.
Signed-off-by: Adam Litke <a...@us.ibm.com>
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 3a43ebf..1029363 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -135,6 +135,7 @@ static int virtio_dev_probe(struct device *_d)
set_bit(i, dev->features);
dev->config->finalize_features(dev);
+ printk("virtio_dev_probe: final features = %lx\n", dev->features[0]);
Looks like leftover debugging.
err = drv->probe(dev);
if (err)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 200c22f..77cb953 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -180,6 +180,45 @@ static void update_balloon_size(struct virtio_balloon *vb)
&actual, sizeof(actual));
}
+static inline void update_stat(struct virtio_device *vdev, int feature,
+ unsigned long value, unsigned offset)
+{
+ if (virtio_has_feature(vdev, feature)) {
+ vdev->config->set(vdev, offset, &value, sizeof(value));
I think this bit assumes a little endian guest. We shouldn't make that
assumption.
For virtio kernel patches, please CC the virtualization list and Rusty
as he's the maintainer. It wouldn't hurt to CC lkml either.
--
Regards,
Anthony Liguori
