From 6b35e40767c6c1ac783330109ae8e0c09ea6bc82 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 4 Feb 2008 23:50:12 -0500 Subject: virtio: balloon driver After discussions with Anthony Liguori, it seems that the virtio balloon can be made even simpler. Here's my attempt. The device configuration tells the driver how much memory it should take from the guest (ie. balloon size). The guest feeds the page numbers it has taken via one virtqueue. A second virtqueue feeds the page numbers the driver wants back: if the device has the VIRTIO_BALLOON_F_MUST_TELL_HOST bit, then this queue is compulsory, otherwise it's advisory (and the guest can simply fault the pages back in). This driver can be enhanced later to deflate the balloon via a shrinker, oom callback or we could even go for a complete set of in-guest regulators. Signed-off-by: Rusty Russell --- drivers/virtio/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/virtio/Kconfig') diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 833db2f36e9..3dd6294d10b 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -23,3 +23,13 @@ config VIRTIO_PCI If unsure, say M. +config VIRTIO_BALLOON + tristate "Virtio balloon driver (EXPERIMENTAL)" + select VIRTIO + select VIRTIO_RING + ---help--- + This driver supports increasing and decreasing the amount + of memory within a KVM guest. + + If unsure, say M. + -- cgit v1.2.3