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

1 files changed, 3 insertions, 1 deletions

diff --git a/monitor.c b/monitor.c
index a928c3eb0d..f142a879f4 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1402,7 +1402,9 @@ static void do_info_balloon(void)
     ram_addr_t actual;
 
     actual = qemu_balloon_status();
-    if (actual == 0)
+    if (kvm_enabled() && !kvm_has_sync_mmu())
+        term_printf("Using KVM without synchronous MMU, ballooning disabled\n");
+    else if (actual == 0)
         term_printf("Ballooning not activated in VM\n");
     else
         term_printf("balloon: actual=%d\n", (int)(actual >> 20));