kernel/linux.git/drivers/misc/vmw_balloon.c, branch v5.15.208

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2026-01-19T12:10:10+00:00

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ] Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

2023-03-11T12:57:38+00:00

[ Upstream commit 209cdbd07cfaa4b7385bad4eeb47e5ec1887d33d ] 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 Cc: VMware PV-Drivers Reviewers Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20230202141100.2291188-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

drivers: vmw_balloon: remove dentry pointer for debugfs

2021-03-10T08:21:02+00:00

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 Cc: "VMware, Inc." Cc: Arnd Bergmann Cc: linux-kernel@vger.kernel.org Acked-by: Nadav Amit Link: https://lore.kernel.org/r/20210216151209.3954129-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

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

2019-12-10T09:15:48+00:00

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

vmw_balloon: Fix offline page marking with compaction

2019-08-28T20:57:07+00:00

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 Reported-by: Thomas Hellstrom Signed-off-by: Nadav Amit Link: https://lore.kernel.org/r/20190820160121.452-1-namit@vmware.com Signed-off-by: Greg Kroah-Hartman

Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2019-07-19T17:42:02+00:00

Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...

Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2019-07-12T19:24:03+00:00

Pull driver core and debugfs updates from Greg KH: "Here is the "big" driver core and debugfs changes for 5.3-rc1 It's a lot of different patches, all across the tree due to some api changes and lots of debugfs cleanups. Other than the debugfs cleanups, in this set of changes we have: - bus iteration function cleanups - scripts/get_abi.pl tool to display and parse Documentation/ABI entries in a simple way - cleanups to Documenatation/ABI/ entries to make them parse easier due to typos and other minor things - default_attrs use for some ktype users - driver model documentation file conversions to .rst - compressed firmware file loading - deferred probe fixes All of these have been in linux-next for a while, with a bunch of merge issues that Stephen has been patient with me for" * tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits) debugfs: make error message a bit more verbose orangefs: fix build warning from debugfs cleanup patch ubifs: fix build warning after debugfs cleanup patch driver: core: Allow subsystems to continue deferring probe drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT arch_topology: Remove error messages on out-of-memory conditions lib: notifier-error-inject: no need to check return value of debugfs_create functions swiotlb: no need to check return value of debugfs_create functions ceph: no need to check return value of debugfs_create functions sunrpc: no need to check return value of debugfs_create functions ubifs: no need to check return value of debugfs_create functions orangefs: no need to check return value of debugfs_create functions nfsd: no need to check return value of debugfs_create functions lib: 842: no need to check return value of debugfs_create functions debugfs: provide pr_fmt() macro debugfs: log errors when something goes wrong drivers: s390/cio: Fix compilation warning about const qualifiers drivers: Add generic helper to match by of_node driver_find_device: Unify the match function with class_find_device() bus_find_device: Unify the match callback with class_find_device ...

vmw_balloon: no need to check return value of debugfs_create functions

2019-06-12T11:37:03+00:00

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 Cc: "VMware, Inc." Cc: Arnd Bergmann Cc: linux-kernel@vger.kernel.org Acked-by: Nadav Amit Signed-off-by: Greg Kroah-Hartman

vmw_balloon: Split refused pages

2019-05-24T18:19:17+00:00

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 Signed-off-by: Nadav Amit Signed-off-by: Greg Kroah-Hartman

vmw_balloon: Add memory shrinker

2019-05-24T18:19:17+00:00

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 Signed-off-by: Nadav Amit Signed-off-by: Greg Kroah-Hartman