vmw_balloon: dynamically allocate the vmw-balloon shrinker

In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the vmw-balloon shrinker, so that it can be freed
asynchronously via RCU. Then it doesn't need to wait for RCU read-side
critical section when releasing the struct vmballoon.

And we can simply exit vmballoon_init() when registering the shrinker
fails. So the shrinker_registered indication is redundant, just remove it.

Link: https://lkml.kernel.org/r/20230911094444.68966-28-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Nadav Amit <namit@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Neil Brown <neilb@suse.de>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sean Paul <sean@poorly.run>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Song Liu <song@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

misc: vmw_balloon: fix memory leak with using debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.

Cc: Nadav Amit <namit@vmware.com>
Cc: VMware PV-Drivers Reviewers <pv-drivers@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230202141100.2291188-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm: shrinkers: provide shrinkers with names

Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.

In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.

The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.

After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40

[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: Convert all PageMovable users to movable_operations

These drivers are rather uncomfortably hammered into the
address_space_operations hole. They aren't filesystems and don't behave
like filesystems. They just need their own movable_operations structure,
which we can point to directly from page->mapping.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

vmw_balloon: Print errors on reset only once

The VMware balloon might be reset multiple times during execution. Print
errors only once to avoid filling the log unnecessarily.

Signed-off-by: Nadav Amit <namit@vmware.com>
Link: https://lore.kernel.org/r/20220322170052.6351-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: vmw_balloon: remove dentry pointer for debugfs

There is no need to keep the dentry pointer around for the created
debugfs file, as it is only needed when removing it from the system.
When it is to be removed, ask debugfs itself for the pointer, to save on
storage and make things a bit simpler.

Cc: Nadav Amit <namit@vmware.com>
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org
Acked-by: Nadav Amit <namit@vmware.com>
Link: https://lore.kernel.org/r/20210216151209.3954129-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: Explicitly include linux/io.h for virt_to_phys()

Through a labyrinthian sequence of includes, usage of virt_to_phys() is
dependent on the include of asm/io.h in x86's asm/realmode.h, which is
included in x86's asm/acpi.h and thus by linux/acpi.h. Explicitly
include linux/io.h to break the dependency on realmode.h so that a
future patch can remove the realmode.h include from acpi.h without
breaking the build.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-9-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

vmw_balloon: Fix offline page marking with compaction

The compaction code already marks pages as offline when it enqueues
pages in the ballooned page list, and removes the mapping when the pages
are removed from the list. VMware balloon also updates the flags,
instead of letting the balloon-compaction logic handle it, which causes
the assertion VM_BUG_ON_PAGE(!PageOffline(page)) to fire, when
__ClearPageOffline is called the second time. This causes the following
crash.

[ 487.104520] kernel BUG at include/linux/page-flags.h:749!
[ 487.106364] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
[ 487.107681] CPU: 7 PID: 1106 Comm: kworker/7:3 Not tainted 5.3.0-rc5balloon #227
[ 487.109196] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[ 487.111452] Workqueue: events_freezable vmballoon_work [vmw_balloon]
[ 487.112779] RIP: 0010:vmballoon_release_page_list+0xaa/0x100 [vmw_balloon]
[ 487.114200] Code: fe 48 c1 e7 06 4c 01 c7 8b 47 30 41 89 c1 41 81 e1 00 01 00 f0 41 81 f9 00 00 00 f0 74 d3 48 c7 c6 08 a1 a1 c0 e8 06 0d e7 ea <0f> 0b 44 89 f6 4c 89 c7 e8 49 9c e9 ea 49 8d 75 08 49 8b 45 08 4d
[ 487.118033] RSP: 0018:ffffb82f012bbc98 EFLAGS: 00010246
[ 487.119135] RAX: 0000000000000037 RBX: 0000000000000001 RCX: 0000000000000006
[ 487.120601] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9a85b6bd7620
[ 487.122071] RBP: ffffb82f012bbcc0 R08: 0000000000000001 R09: 0000000000000000
[ 487.123536] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb82f012bbd00
[ 487.125002] R13: ffffe97f4598d9c0 R14: 0000000000000000 R15: ffffb82f012bbd34
[ 487.126463] FS: 0000000000000000(0000) GS:ffff9a85b6bc0000(0000) knlGS:0000000000000000
[ 487.128110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 487.129316] CR2: 00007ffe6e413ea0 CR3: 0000000230b18001 CR4: 00000000003606e0
[ 487.130812] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 487.132283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 487.133749] Call Trace:
[ 487.134333] vmballoon_deflate+0x22c/0x390 [vmw_balloon]
[ 487.135468] vmballoon_work+0x6e7/0x913 [vmw_balloon]
[ 487.136711] ? process_one_work+0x21a/0x5e0
[ 487.138581] process_one_work+0x298/0x5e0
[ 487.139926] ? vmballoon_migratepage+0x310/0x310 [vmw_balloon]
[ 487.141610] ? process_one_work+0x298/0x5e0
[ 487.143053] worker_thread+0x41/0x400
[ 487.144389] kthread+0x12b/0x150
[ 487.145582] ? process_one_work+0x5e0/0x5e0
[ 487.146937] ? kthread_create_on_node+0x60/0x60
[ 487.148637] ret_from_fork+0x3a/0x50

Fix it by updating the PageOffline indication only when a 2MB page is
enqueued and dequeued. The 4KB pages will be handled correctly by the
balloon compaction logic.

Fixes: 83a8afa72e9c ("vmw_balloon: Compaction support")
Cc: David Hildenbrand <david@redhat.com>
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Link: https://lore.kernel.org/r/20190820160121.452-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: Julien Freche <jfreche@vmware.com>
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org
Acked-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: Split refused pages

The hypervisor might refuse to inflate pages. While the balloon driver
handles this scenario correctly, a refusal to inflate a 2MB pages might
cause the same page to be allocated again later just for its inflation
to be refused again. This wastes energy and time.

To avoid this situation, split the 2MB page to 4KB pages, and then try
to inflate each one individually. Most of the 4KB pages out of the 2MB
should be inflated successfully, and the balloon is likely to prevent
the scenario of repeated refused inflation.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: Add memory shrinker

Add a shrinker to the VMware balloon to prevent out-of-memory events.
We reuse the deflate logic for this matter. Deadlocks should not happen,
as no memory allocation is performed while the locks of the
communication (batch/page) and page-list are taken. In the unlikely
event in which the configuration semaphore is taken for write we bail
out and fail gracefully (causing processes to be killed).

Once the shrinker is called, inflation is postponed for few seconds.
The timeout is updated without any lock, but this should not cause any
races, as it is written and read atomically.

This feature is disabled by default, since it might cause performance
degradation.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: Compaction support

Add support for compaction for VMware balloon. Since unlike the virtio
balloon, we also support huge-pages, which are not going through
compaction, we keep these pages in vmballoon and handle this list
separately. We use the same lock to protect both lists, as this lock is
not supposed to be contended.

Doing so also eliminates the need for the page_size lists. We update the
accounting as needed to reflect inflation, deflation and migration to be
reflected in vmstat.

Since VMware balloon now provides statistics for inflation, deflation
and migration in vmstat, select MEMORY_BALLOON in Kconfig.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: mark inflated pages PG_offline

Mark inflated and never onlined pages PG_offline, to tell the world that
the content is stale and should not be dumped.

[david@redhat.com: use vmballoon_page_in_frames more widely]
Link: http://lkml.kernel.org/r/20181122100627.5189-7-david@redhat.com
Link: http://lkml.kernel.org/r/20181119101616.8901-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Nadav Amit <namit@vmware.com>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmw_balloon: release lock on error in vmballoon_reset()

We added some locking to this function but forgot to drop the lock on
these two error paths. This bug would lead to an immediate deadlock.

Fixes: c7b3690fb152 ("vmw_balloon: stats rework")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: support 64-bit memory limit

Currently, the balloon driver would fail to run if memory is greater
than 16TB of vRAM. Previous patches have already converted the balloon
target and size to 64-bit, so all that is left to do add is to avoid
asserting memory is smaller than 16TB if the hypervisor supports 64-bits
target.

The driver advertises a new capability VMW_BALLOON_64_BITS_TARGET.
Hypervisors that support 16TB of memory or more will report that this
capability is enabled.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: remove the version number

Following the new kernel policy.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm: convert totalram_pages and totalhigh_pages variables to atomic

totalram_pages and totalhigh_pages are made static inline function.

Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

misc: remove GENWQE_DEBUGFS_RO()

We already have the DEFINE_SHOW_ATTRIBUTE.There is no need to define
such a macro,so remove GENWQE_DEBUGFS_RO.Also use DEFINE_SHOW_ATTRIBUTE
to simplify some code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: add reset stat

It is useful to expose how many times the balloon resets. If it happens
more than very rarely - this is an indication for a problem.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: general style cleanup

Change all the remaining return values to int to avoid mistakes. Reduce
indentation when possible.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: rework the inflate and deflate loops

In preparation for supporting compaction and OOM notification, this
patch reworks the inflate/deflate loops. The main idea is to separate
the allocation, communication with the hypervisor, and the handling of
errors from each other. Doing will allow us to perform concurrent
inflation and deflation, excluding the actual communication with the
hypervisor.

To do so, we need to get rid of the remaining global state that is kept
in the balloon struct, specifically the refuse_list. When the VM
communicates with the hypervisor, it does not free or put back pages
to the balloon list and instead only moves the pages whose status
indicated failure into a refuse_list on the stack. Once the operation
completes, the inflation or deflation functions handle the list
appropriately.

As we do that, we can consolidate the communication with the hypervisor
for both the lock and unlock operations into a single function. We also
reuse the deflation function for popping the balloon.

As a preparation for preventing races, we hold a spinlock when the
communication actually takes place, and use atomic operations for
updating the balloon size. The balloon page list is still racy and will
be handled in the next patch.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: stats rework

To allow the balloon statistics to be updated concurrently, we change
the statistics to be held per core and aggregate it when needed.

To avoid the memory overhead of keeping the statistics per core, and
since it is likely not used by most users, we start updating the
statistics only after the first use. A read-write semaphore is used to
protect the statistics initialization and avoid races. This semaphore is
(and will) be used to protect configuration changes during reset.

While we are at it, address some other issues: change the statistics
update to inline functions instead of define; use ulong for saving the
statistics; and clean the statistics printouts.

Note that this patch changes the format of the outputs. If there are any
automatic tools that use the statistics, they might fail.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: simplify vmballoon_send_get_target()

As we want to leave as little as possible on the global balloon
structure, to avoid possible future races, we want to get rid sysinfo.
We can actually get the total_ram directly, and simplify the logic of
vmballoon_send_get_target() a little.

While we are doing that, let's return int and avoid mistakes due to
bool/int conversions.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: refactor change size from vmballoon_work

The required change in the balloon size is currently computed in
vmballoon_work(), vmballoon_inflate() and vmballoon_deflate(). Refactor
it to simplify the next patches.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: rename VMW_BALLOON_2M_SHIFT to VMW_BALLOON_2M_ORDER

The name of the macro'd VMW_BALLOON_2M_SHIFT is misleading. The value
reflects 2M huge-page order. Unfortunately, we cannot use
HPAGE_PMD_ORDER, since it is not defined when transparent huge-pages are
off, so we need to define our own one.

Rename it to VMW_BALLOON_2M_ORDER. No functional change.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: treat all refused pages equally

Currently, when the hypervisor rejects a page during lock operation, the
VM treats pages differently according to the error-code: in certain
cases the page is immediately freed, and in others it is put on a
rejection list and only freed later.

The behavior does not make too much sense. If the page is freed
immediately it is very likely to be used again in the next batch of
allocations, and be rejected again.

In addition, for support of compaction and OOM notifiers, we wish to
separate the logic that communicates with the hypervisor (as well as
analyzes the status of each page) from the logic that allocates or free
pages.

Treat all errors the same way, queuing the pages on the refuse list.
Move to the next allocation size (4k) when too many pages are refused.
Free the refused pages when moving to the next size to avoid situations
in which too much memory is waiting to be freed on the refused list.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: change batch/single lock abstractions

The current abstractions for batch vs single operations seem suboptimal
and complicate the implementation of additional features (OOM,
compaction).

The immediate problem of the current abstractions is that they cause
differences in how operations are handled when batching is on or off.
For example, the refused_alloc counter is not updated when batching is
on. These discrepancies are caused by code redundancies.

Instead, this patch presents three type of operations, according to
whether batching is on or off: (1) add page, (2) communication with the
hypervisor and (3) retrieving the status of a page.

To avoid the overhead of virtual functions, and since we do not expect
additional interfaces for communication with the hypervisor, we use
static keys instead of virtual functions.

Finally, while we are at it, change vmballoon_init_batching() to return
int instead of bool, to be consistent in the return type and avoid
potential coding errors.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: remove sleeping allocations

Splitting the allocations between sleeping and non-sleeping made some
sort of sense as long as rate-limiting was enabled. Now that it is
removed, we need to decide - either we want sleeping allocations or not.

Since no other Linux balloon driver (hv, Xen, virtio) uses sleeping
allocations, use the same approach.

We do distinguish, however, between 2MB allocations and 4kB allocations
and prevent reclamation on 2MB. In both cases, we avoid using emergency
low-memory pools, as it may cause undesired effects.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: simplifying batch access

The use of accessors for batch entries complicates the code and makes it
less readable. Remove it an instead use bit-fields.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: merge send_lock and send_unlock path

The lock and unlock code paths are very similar, so avoid the duplicate
code by merging them together.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: unify commands tracing and stats

Now that we have a single point, unify the tracing and collecting the
statistics for commands and their failure. While it might somewhat
reduce the control over debugging, it cleans the code a lot.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: handle commands in a single function.

By inlining the hypercall interface, we can unify several operations
into one central point in the code:

- Updating the target.
- Updating when a reset is needed.
- Update statistics (which will be done later in the patch-set).
- Print debug-messages (although they cannot be enabled as selectively).

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: fix inflation with batching

Embarrassingly, the recent fix introduced worse problem than it solved,
causing the balloon not to inflate. The VM informed the hypervisor that
the pages for lock/unlock are sitting in the wrong address, as it used
the page that is used the uninitialized page variable.

Fixes: b23220fe054e9 ("vmw_balloon: fixing double free when batching mode is off")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: update copyright message

Removing the GPL wording and replace it with an SPDX tag. The immediate
trigger for doing it now is the need to remove the list of maintainers
from the source file, as the maintainer list changed.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: remove inflation rate limiting

Since commit 33d268ed0019 ("VMware balloon: Do not limit the amount of
frees and allocations in non-sleep mode."), the allocations are not
increased, and therefore balloon inflation rate limiting is in practice
broken.

While we can restore rate limiting, in practice we see that it can
result in adverse effect, as the hypervisor throttles down the VM if it
does not respond well enough, or alternatively causes it to perform very
poorly as the host swaps out the VM memory. Throttling the VM down can
even have a cascading effect, in which the VM reclaims memory even
slower and consequentially throttled down even further.

We therefore remove all the rate limiting mechanisms, including the slow
allocation cycles, as they are likely to do more harm than good.

Fixes: 33d268ed0019 ("VMware balloon: Do not limit the amount of frees and allocations in non-sleep mode.")
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: fix VMCI use when balloon built into kernel

Currently, when all modules, including VMCI and VMware balloon are built
into the kernel, the initialization of the balloon happens before the
VMCI is probed. As a result, the balloon fails to initialize the VMCI
doorbell, which it uses to get asynchronous requests for balloon size
changes.

The problem can be seen in the logs, in the form of the following
message:
"vmw_balloon: failed to initialize vmci doorbell"

The driver would work correctly but slightly less efficiently, probing
for requests periodically. This patch changes the balloon to be
initialized using late_initcall() instead of module_init() to address
this issue. It does not address a situation in which VMCI is built as a
module and the balloon is built into the kernel.

Fixes: 48e3d668b790 ("VMware balloon: Enable notification via VMCI")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: VMCI_DOORBELL_SET does not check status

When vmballoon_vmci_init() sets a doorbell using VMCI_DOORBELL_SET, for
some reason it does not consider the status and looks at the result.
However, the hypervisor does not update the result - it updates the
status. This might cause VMCI doorbell not to be enabled, resulting in
degraded performance.

Fixes: 48e3d668b790 ("VMware balloon: Enable notification via VMCI")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: do not use 2MB without batching

If the hypervisor sets 2MB batching is on, while batching is cleared,
the balloon code breaks. In this case the legacy mechanism is used with
2MB page. The VM would report a 2MB page is ballooned, and the
hypervisor would only take the first 4KB.

While the hypervisor should not report such settings, make the code more
robust by not enabling 2MB support without batching.

Fixes: 365bd7ef7ec8e ("VMware balloon: Support 2m page ballooning.")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: fix inflation of 64-bit GFNs

When balloon batching is not supported by the hypervisor, the guest
frame number (GFN) must fit in 32-bit. However, due to a bug, this check
was mistakenly ignored. In practice, when total RAM is greater than
16TB, the balloon does not work currently, making this bug unlikely to
happen.

Fixes: ef0f8f112984 ("VMware balloon: partially inline vmballoon_reserve_page.")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: fixing double free when batching mode is off

The balloon.page field is used for two different purposes if batching is
on or off. If batching is on, the field point to the page which is used
to communicate with with the hypervisor. If it is off, balloon.page
points to the page that is about to be (un)locked.

Unfortunately, this dual-purpose of the field introduced a bug: when the
balloon is popped (e.g., when the machine is reset or the balloon driver
is explicitly removed), the balloon driver frees, unconditionally, the
page that is held in balloon.page. As a result, if batching is
disabled, this leads to double freeing the last page that is sent to the
hypervisor.

The following error occurs during rmmod when kernel checkers are on, and
the balloon is not empty:

[ 42.307653] ------------[ cut here ]------------
[ 42.307657] Kernel BUG at ffffffffba1e4b28 [verbose debug info unavailable]
[ 42.307720] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 42.312512] Modules linked in: vmw_vsock_vmci_transport vsock ppdev joydev vmw_balloon(-) input_leds serio_raw vmw_vmci parport_pc shpchp parport i2c_piix4 nfit mac_hid autofs4 vmwgfx drm_kms_helper hid_generic syscopyarea sysfillrect usbhid sysimgblt fb_sys_fops hid ttm mptspi scsi_transport_spi ahci mptscsih drm psmouse vmxnet3 libahci mptbase pata_acpi
[ 42.312766] CPU: 10 PID: 1527 Comm: rmmod Not tainted 4.12.0+ #5
[ 42.312803] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2016
[ 42.313042] task: ffff9bf9680f8000 task.stack: ffffbfefc1638000
[ 42.313290] RIP: 0010:__free_pages+0x38/0x40
[ 42.313510] RSP: 0018:ffffbfefc163be98 EFLAGS: 00010246
[ 42.313731] RAX: 000000000000003e RBX: ffffffffc02b9720 RCX: 0000000000000006
[ 42.313972] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9bf97e08e0a0
[ 42.314201] RBP: ffffbfefc163be98 R08: 0000000000000000 R09: 0000000000000000
[ 42.314435] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffc02b97e4
[ 42.314505] R13: ffffffffc02b9748 R14: ffffffffc02b9728 R15: 0000000000000200
[ 42.314550] FS: 00007f3af5fec700(0000) GS:ffff9bf97e080000(0000) knlGS:0000000000000000
[ 42.314599] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 42.314635] CR2: 00007f44f6f4ab24 CR3: 00000003a7d12000 CR4: 00000000000006e0
[ 42.314864] Call Trace:
[ 42.315774] vmballoon_pop+0x102/0x130 [vmw_balloon]
[ 42.315816] vmballoon_exit+0x42/0xd64 [vmw_balloon]
[ 42.315853] SyS_delete_module+0x1e2/0x250
[ 42.315891] entry_SYSCALL_64_fastpath+0x23/0xc2
[ 42.315924] RIP: 0033:0x7f3af5b0e8e7
[ 42.315949] RSP: 002b:00007fffe6ce0148 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 42.315996] RAX: ffffffffffffffda RBX: 000055be676401e0 RCX: 00007f3af5b0e8e7
[ 42.316951] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055be67640248
[ 42.317887] RBP: 0000000000000003 R08: 0000000000000000 R09: 1999999999999999
[ 42.318845] R10: 0000000000000883 R11: 0000000000000206 R12: 00007fffe6cdf130
[ 42.319755] R13: 0000000000000000 R14: 0000000000000000 R15: 000055be676401e0
[ 42.320606] Code: c0 74 1c f0 ff 4f 1c 74 02 5d c3 85 f6 74 07 e8 0f d8 ff ff 5d c3 31 f6 e8 c6 fb ff ff 5d c3 48 c7 c6 c8 0f c5 ba e8 58 be 02 00 <0f> 0b 66 0f 1f 44 00 00 66 66 66 66 90 48 85 ff 75 01 c3 55 48
[ 42.323462] RIP: __free_pages+0x38/0x40 RSP: ffffbfefc163be98
[ 42.325735] ---[ end trace 872e008e33f81508 ]---

To solve the bug, we eliminate the dual purpose of balloon.page.

Fixes: f220a80f0c2e ("VMware balloon: add batching to the vmw_balloon.")
Cc: stable@vger.kernel.org
Reported-by: Oleksandr Natalenko <onatalen@redhat.com>
Signed-off-by: Gil Kupfer <gilkup@gmail.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/virt: Add enum for hypervisors to replace x86_hyper

The x86_hyper pointer is only used for checking whether a virtual
device is supporting the hypervisor the system is running on.

Use an enum for that purpose instead and drop the x86_hyper pointer.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Xavier Deguillard <xdeguillard@vmware.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: akataria@vmware.com
Cc: arnd@arndb.de
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: dmitry.torokhov@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: linux-graphics-maintainer@vmware.com
Cc: linux-input@vger.kernel.org
Cc: moltmann@vmware.com
Cc: pbonzini@redhat.com
Cc: pv-drivers@vmware.com
Cc: rkrcmar@redhat.com
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM

__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep. Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep. The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

VMware balloon: Enable notification via VMCI

Get notified immediately when a balloon target is set, instead of waiting for
up to one second.

The up-to 1 second gap could be long enough to cause swapping inside of the
VM that receives the VM.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Tested-by: Siva Sankar Reddy B <sankars@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Treat init like reset

Unify the behavior of the first start of the balloon and a reset. Also on
unload, declare that the balloon driver does not have any capabilities
anymore.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Support 2m page ballooning.

2m ballooning significantly reduces the hypervisor side (and guest side)
overhead of ballooning and unballooning.

hypervisor only:
balloon unballoon
4 KB 2 GB/s 2.6 GB/s
2 MB 54 GB/s 767 GB/s

Use 2 MB pages as the hypervisor is alwys 64bit and 2 MB is the smallest
supported super-page size.

The code has to run on older versions of ESX and old balloon drivers run on
newer version of ESX. Hence match the capabilities with the host before 2m
page ballooning could be enabled.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Do not limit the amount of frees and allocations in non-sleep mode.

When VMware's hypervisor requests a VM to reclaim memory this is preferrably done
via ballooning. If the balloon driver does not return memory fast enough, more
drastic methods, such as hypervisor-level swapping are needed. These other methods
cause performance issues, e.g. hypervisor-level swapping requires the hypervisor to
swap in a page syncronously while the virtual CPU is blocked.

Hence it is in the interest of the VM to balloon memory as fast as possible. The
problem with doing this is that the VM might end up doing nothing else than
ballooning and the user might notice that the VM is stalled, esp. when the VM has
only a single virtual CPU.

This is less of a problem if the VM and the hypervisor perform balloon operations
faster. Also the balloon driver yields regularly, hence on a single virtual CPU
the Linux scheduler should be able to properly time-slice between ballooning and
other tasks.

Testing Done: quickly ballooned a lot of pages while wathing if there are any
perceived hickups (periods of non-responsiveness) in the execution of the
linux VM. No such hickups were seen.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Show capabilities of balloon and resulting capabilities in the debug-fs node.

This helps with debugging vmw_balloon behavior, as it is clear what
functionality is enabled.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Update balloon target on each lock/unlock.

Instead of waiting for the next GET_TARGET command, we can react faster
by exploiting the fact that each hypervisor call also returns the
balloon target.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: add batching to the vmw_balloon.

Introduce a new capability to the driver that allow sending 512 pages in
one hypervisor call. This reduce the cost of the driver when reclaiming
memory.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: Add support for balloon capabilities.

In order to extend the balloon protocol, the hypervisor and the guest
driver need to agree on a set of supported functionality to use.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VMware balloon: partially inline vmballoon_reserve_page.

This split the function in two: the allocation part is inlined into the
inflate function and the lock part is kept into his own function.

This change is needed in order to be able to allocate more than one page
before doing the hypervisor call.

Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS: add entry for VMware Balloon driver

Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: vmw_balloon: Remove braces to fix build for clang.

Based on a patch from: PaX Team <pageexec at freemail.hu> in a mailing
list message at:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120507/142707.html

Clang chokes on the notation "inl (%dx)" but works for "inl %dx"; GNU as accepts both forms.

CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vmw_balloon: fix for a -Wuninitialized warning

Fix for a -Wuninitialized compiler warning. Changed return value of
vmballoon_send_lock_page() from bool to int to be able to distinguish
between the error cases to avoid uninitialized use of hv_status in
vmballoon_reserve_page()

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/vmw_balloon.c: fix typo in code comment

Fix typo in code comment.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop

In vmballoon_reserve_page(), flags has been passed from the callee
function (vmballoon_inflate here). So, we can determine can_sleep outside
the loop.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Vmware balloon: switch to using sysem-wide freezable workqueue

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: Dmitry Torokhov <dtor@vmware.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'

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: Tejun Heo <tj@kernel.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Dmitry 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>

VMware balloon: stop locking pages when hypervisor tells us enough

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: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmware balloon: rename module

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: Dmitry Torokhov <dtor@vmware.com>
Acked-by: Bhavesh Davda <bhavesh@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>