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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-12-04 20:33:06 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-12-04 20:33:06 +0000
commitbd3220870f677d5b08f59d7e786ac18bde1c1b7c (patch)
tree2f790c4ead1b6829a8433b37ba95e9b632d5f45e /hw/virtio-balloon.h
parentdf751fa8bfed4408ca091a7badd75c5ab80f71de (diff)
Add virtio-balloon support
This adds a VirtIO based balloon driver. It uses madvise() to actually balloon the memory when possible. Until 2.6.27, KVM forced memory pinning so we must disable ballooning unless the kernel actually supports it when using KVM. It's always safe when using TCG. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5874 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'hw/virtio-balloon.h')
-rw-r--r--hw/virtio-balloon.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/hw/virtio-balloon.h b/hw/virtio-balloon.h
new file mode 100644
index 0000000000..c71f9709bf
--- /dev/null
+++ b/hw/virtio-balloon.h
@@ -0,0 +1,42 @@
+/*
+ * Virtio Support
+ *
+ * Copyright IBM, Corp. 2007-2008
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ * Rusty Russell <rusty@rustcorp.com.au>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef _QEMU_VIRTIO_BALLOON_H
+#define _QEMU_VIRTIO_BALLOON_H
+
+#include "virtio.h"
+#include "pci.h"
+
+/* from Linux's linux/virtio_balloon.h */
+
+/* The ID for virtio_balloon */
+#define VIRTIO_ID_BALLOON 5
+
+/* The feature bitmap for virtio balloon */
+#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
+
+/* Size of a PFN in the balloon interface. */
+#define VIRTIO_BALLOON_PFN_SHIFT 12
+
+struct virtio_balloon_config
+{
+ /* Number of pages host wants Guest to give up. */
+ uint32_t num_pages;
+ /* Number of pages we've actually got in balloon. */
+ uint32_t actual;
+};
+
+void *virtio_balloon_init(PCIBus *bus);
+
+#endif