From 453dc65931915abc61f92e12bba1fc4747ff5542 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Fri, 23 Apr 2010 13:18:08 -0400 Subject: VMware Balloon driver This is a standalone version of VMware Balloon driver. Ballooning is a technique that allows hypervisor dynamically limit the amount of memory available to the guest (with guest cooperation). In the overcommit scenario, when hypervisor set detects that it needs to shuffle some memory, it instructs the driver to allocate certain number of pages, and the underlying memory gets returned to the hypervisor. Later hypervisor may return memory to the guest by reattaching memory to the pageframes and instructing the driver to "deflate" balloon. We are submitting a standalone driver because KVM maintainer (Avi Kivity) expressed opinion (rightly) that our transport does not fit well into virtqueue paradigm and thus it does not make much sense to integrate with virtio. There were also some concerns whether current ballooning technique is the right thing. If there appears a better framework to achieve this we are prepared to evaluate and switch to using it, but in the meantime we'd like to get this driver upstream. We want to get the driver accepted in distributions so that users do not have to deal with an out-of-tree module and many distributions have "upstream first" requirement. The driver has been shipping for a number of years and users running on VMware platform will have it installed as part of VMware Tools even if it will not come from a distribution, thus there should not be additional risk in pulling the driver into mainline. The driver will only activate if host is VMware so everyone else should not be affected at all. Signed-off-by: Dmitry Torokhov Cc: Avi Kivity Cc: Jeremy Fitzhardinge Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/cpu/vmware.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/cpu/vmware.c') diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 1cbed97b59c..dfdb4dba232 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -22,6 +22,7 @@ */ #include +#include #include #include #include @@ -101,6 +102,7 @@ int vmware_platform(void) return 0; } +EXPORT_SYMBOL(vmware_platform); /* * VMware hypervisor takes care of exporting a reliable TSC to the guest. -- cgit v1.2.3-18-g5258