With the arrival of concurrency-managed workqueues there is no need for
our driver to use dedicated workqueue; system-wide one should suffice just
fine.

[akpm@linux-foundation.org: fix comment layout & grammar]
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'.  The former is the more prominent one.  The latter is
mostly used by workqueue and in a few other odd places.  Unify the
spelling to 'freezable'.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NDmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>

When hypervisor decides to decrease target balloon size while the balloon
driver tries to lock pages hypervisor may respond with
VMW_BALLOON_PPN_NOTNEEDED.  Use this data and immediately stop reserving
pages and wait for the next update cycle to fetch new target instead of
continuing trying to lock pages until size of refused list grows above
VMW_BALLOON_MAX_REFUSED (16) pages.

As a result the driver stops bothering the hypervisor with its attempts to
lock more pages that are not needed anymore.  Most likely next order from
hypervisor will be to reduce ballon size anyway.

It is a small optimization.
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In an effort to minimize customer confusion we want to unify naming
convention for VMware-provided kernel modules.  This change renames the
balloon driver from vmware_ballon to vmw_balloon.

We expect to follow this naming convention (vmw_<module_name>) for all
modules that are part of mainline kernel and/or being distributed by
VMware, with the sole exception of vmxnet3 driver (since the name of
mainline driver happens to match with the name used in VMware Tools).
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Acked-by: NBhavesh Davda <bhavesh@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Limit number of accumulated non-balloonable pages during inflation cycle,
otherwise there is a chance we will be spinning and growing the list
forever.  This happens during torture tests when balloon target changes
while we are in the middle of inflation cycle and monitor starts refusing
to lock pages (since they are not needed anymore).
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Acked-by: NBhavesh Davda <bhavesh@vmware.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Modify the VMware balloon driver to match the new x86_hyper API.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>

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: NDmitry Torokhov <dtor@vmware.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>