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* virtio_balloon: transitional interfaceMichael S. Tsirkin2015-04-151-6/+15
| | | | | | | | | | | Virtio 1.0 doesn't include a modern balloon device. But it's not a big change to support a transitional balloon device: this has the advantage of supporting existing drivers, transparently. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-balloon: do not call blocking ops when !TASK_RUNNINGMichael S. Tsirkin2015-03-101-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | virtio balloon has this code: wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 || vb->need_stats_update || kthread_should_stop() || freezing(current)); Which is a problem because towards_target() call might block after wait_event_interruptible sets task state to TAST_INTERRUPTIBLE, causing the task_struct::state collision typical of nesting of sleeping primitives See also http://lwn.net/Articles/628628/ or Thomas's bug report http://article.gmane.org/gmane.linux.kernel.virtualization/24846 for a fuller explanation. To fix, rewrite using wait_woken. Cc: stable@vger.kernel.org Reported-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_balloon: set DRIVER_OK before using deviceMichael S. Tsirkin2015-03-101-0/+2
| | | | | | | | | | | | | | | | | virtio spec requires that all drivers set DRIVER_OK before using devices. While balloon isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio balloon might violate this rule: probe calls kthread_run before setting DRIVER_OK, which might run immediately and cause balloon to inflate/deflate. To fix, call virtio_device_ready before running the kthread. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* virtio_balloon: coding style fixesMichael S. Tsirkin2015-01-211-2/+1
| | | | | | | | | | | Most of our code has struct foo { } Fix two instances where balloon is inconsistent. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio/balloon: verify device has config spaceMichael S. Tsirkin2015-01-211-0/+6
| | | | | | | | | | Some devices might not implement config space access (e.g. remoteproc used not to - before 3.9). virtio/balloon needs config space access so make it fail gracefully if not there. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_balloon: free some memory from balloon on OOMRaushaniya Maksudova2014-11-111-0/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Excessive virtio_balloon inflation can cause invocation of OOM-killer, when Linux is under severe memory pressure. Various mechanisms are responsible for correct virtio_balloon memory management. Nevertheless it is often the case that these control tools does not have enough time to react on fast changing memory load. As a result OS runs out of memory and invokes OOM-killer. The balancing of memory by use of the virtio balloon should not cause the termination of processes while there are pages in the balloon. Now there is no way for virtio balloon driver to free some memory at the last moment before some process will be get killed by OOM-killer. This does not provide a security breach as balloon itself is running inside guest OS and is working in the cooperation with the host. Thus some improvements from guest side should be considered as normal. To solve the problem, introduce a virtio_balloon callback which is expected to be called from the oom notifier call chain in out_of_memory() function. If virtio balloon could release some memory, it will make the system to return and retry the allocation that forced the out of memory killer to run. Allocate virtio feature bit for this: it is not set by default, the the guest will not deflate virtio balloon on OOM without explicit permission from host. Signed-off-by: Raushaniya Maksudova <rmaksudova@parallels.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_balloon: return the amount of freed memory from leak_balloon()Raushaniya Maksudova2014-11-111-1/+4
| | | | | | | | | | | This value would be useful in the next patch to provide the amount of the freed memory for OOM killer. Signed-off-by: Raushaniya Maksudova <rmaksudova@parallels.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2014-10-181-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio updates from Rusty Russell: "One cc: stable commit, the rest are a series of minor cleanups which have been sitting in MST's tree during my vacation. I changed a function name and made one trivial change, then they spent two days in linux-next" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits) virtio-rng: refactor probe error handling virtio_scsi: drop scan callback virtio_balloon: enable VQs early on restore virtio_scsi: fix race on device removal virito_scsi: use freezable WQ for events virtio_net: enable VQs early on restore virtio_console: enable VQs early on restore virtio_scsi: enable VQs early on restore virtio_blk: enable VQs early on restore virtio_scsi: move kick event out from virtscsi_init virtio_net: fix use after free on allocation failure 9p/trans_virtio: enable VQs early virtio_console: enable VQs early virtio_blk: enable VQs early virtio_net: enable VQs early virtio: add API to enable VQs early virtio_net: minor cleanup virtio-net: drop config_mutex virtio_net: drop config_enable virtio-blk: drop config_mutex ...
| * virtio_balloon: enable VQs early on restoreMichael S. Tsirkin2014-10-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | virtio spec requires drivers to set DRIVER_OK before using VQs. This is set automatically after resume returns, virtio balloon violated this rule by adding bufs, which causes the VQ to be used directly within restore. To fix, call virtio_device_ready before using VQ. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | mm/balloon_compaction: add vmstat counters and kpageflags bitKonstantin Khlebnikov2014-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always mark pages with PageBalloon even if balloon compaction is disabled and expose this mark in /proc/kpageflags as KPF_BALLOON. Also this patch adds three counters into /proc/vmstat: "balloon_inflate", "balloon_deflate" and "balloon_migrate". They accumulate balloon activity. Current size of balloon is (balloon_inflate - balloon_deflate) pages. All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON. It should be selected by ballooning driver which wants use this feature. Currently virtio-balloon is the only user. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/balloon_compaction: remove balloon mapping and flag AS_BALLOON_MAPKonstantin Khlebnikov2014-10-091-47/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | Now ballooned pages are detected using PageBalloon(). Fake mapping is no longer required. This patch links ballooned pages to balloon device using field page->private instead of page->mapping. Also this patch embeds balloon_dev_info directly into struct virtio_balloon. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/balloon_compaction: redesign ballooned pages managementKonstantin Khlebnikov2014-10-091-8/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha Levin reported KASAN splash inside isolate_migratepages_range(). Problem is in the function __is_movable_balloon_page() which tests AS_BALLOON_MAP in page->mapping->flags. This function has no protection against anonymous pages. As result it tried to check address space flags inside struct anon_vma. Further investigation shows more problems in current implementation: * Special branch in __unmap_and_move() never works: balloon_page_movable() checks page flags and page_count. In __unmap_and_move() page is locked, reference counter is elevated, thus balloon_page_movable() always fails. As a result execution goes to the normal migration path. virtballoon_migratepage() returns MIGRATEPAGE_BALLOON_SUCCESS instead of MIGRATEPAGE_SUCCESS, move_to_new_page() thinks this is an error code and assigns newpage->mapping to NULL. Newly migrated page lose connectivity with balloon an all ability for further migration. * lru_lock erroneously required in isolate_migratepages_range() for isolation ballooned page. This function releases lru_lock periodically, this makes migration mostly impossible for some pages. * balloon_page_dequeue have a tight race with balloon_page_isolate: balloon_page_isolate could be executed in parallel with dequeue between picking page from list and locking page_lock. Race is rare because they use trylock_page() for locking. This patch fixes all of them. Instead of fake mapping with special flag this patch uses special state of page->_mapcount: PAGE_BALLOON_MAPCOUNT_VALUE = -256. Buddy allocator uses PAGE_BUDDY_MAPCOUNT_VALUE = -128 for similar purpose. Storing mark directly in struct page makes everything safer and easier. PagePrivate is used to mark pages present in page list (i.e. not isolated, like PageLRU for normal pages). It replaces special rules for reference counter and makes balloon migration similar to migration of normal pages. This flag is protected by page_lock together with link to the balloon device. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Link: http://lkml.kernel.org/p/53E6CEAA.9020105@oracle.com Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: <stable@vger.kernel.org> [3.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio_balloon: don't crash if virtqueue is broken.Rusty Russell2014-03-131-5/+3
| | | | | | | | A bad implementation of virtio might cause us to mark the virtqueue broken: we'll dev_err() in that case, and the device is useless, but let's not BUG(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_balloon: don't softlockup on huge balloon changes.Rusty Russell2014-03-131-0/+6
| | | | | | | | | | | | | | | When adding or removing 100G from a balloon: BUG: soft lockup - CPU#0 stuck for 22s! [vballoon:367] We have a wait_event_interruptible(), but the condition is always true (more ballooning to do) so we don't ever sleep. We also have a wait_event() for the host to ack, but that is also always true as QEMU is synchronous for balloon operations. Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com> Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2014-01-221-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio update from Rusty Russell: "A few simple fixes. Quiet cycle" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: drivers: virtio: Mark function virtballoon_migratepage() as static in virtio_balloon.c virtio-scsi: Fix hotcpu_notifier use-after-free with virtscsi_freeze virtio: pci: remove unnecessary pci_set_drvdata()
| * drivers: virtio: Mark function virtballoon_migratepage() as static in ↵Rashika Kheria2014-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | virtio_balloon.c Mark the function virtballoon_migratepage() as static in virtio_balloon.c because it is not used outside this file. This eliminates the following warning in virtio_balloon.c: drivers/virtio/virtio_balloon.c:372:5: warning: no previous prototype for ‘virtballoon_migratepage’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | virtio_balloon: update_balloon_size(): update correct fieldLuiz Capitulino2013-12-051-1/+1
|/ | | | | | | | | | | | | According to the virtio spec, the device configuration field that should be updated after an inflation or deflation operation is the 'actual' field, not the 'num_pages' one. Commit 855e0c5288177bcb193f6f6316952d2490478e1c swapped them in update_balloon_size(). Fix it. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Fixes: 855e0c5288177bcb193f6f6316952d2490478e1c
* virtio: use size-based config accessors.Rusty Russell2013-10-171-6/+4
| | | | | | | | | This lets the transport do endian conversion if necessary, and insulates the drivers from the difference. Most drivers can use the simple helpers virtio_cread() and virtio_cwrite(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: pm: use CONFIG_PM_SLEEP instead of CONFIG_PMAaron Lu2013-09-231-2/+2
| | | | | | | | | | | The freeze and restore functions defined in virtio drivers are used for suspend and hibernate, so CONFIG_PM_SLEEP is more appropriate than CONFIG_PM. This patch replace all CONFIG_PM with CONFIG_PM_SLEEP for virtio drivers that implement freeze and restore callbacks. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2013-07-101-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio updates from Rusty Russell: "No real surprises" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: MAINTAINERS: add tools/virtio/ under virtio tools/virtio: move module license stub to module.h virtio: include asm/barrier explicitly virtio: VIRTIO_F_ANY_LAYOUT feature lguest: fix example launcher compilation for broken glibc headers. virtio-net: fix the race between channels setting and refill tools/lguest: real barriers. tools/lguest: fix missing rmb(). virtio_balloon: leak_balloon(): only tell host if we got pages deflated virtio-pci: fix leaks of msix_affinity_masks Fix comment typo "CONFIG_PAE"
| * virtio_balloon: leak_balloon(): only tell host if we got pages deflatedLuiz Capitulino2013-07-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | balloon_page_dequeue() can return NULL. If it does for the first page being freed then leak_balloon() will create a scatter list with len=0. Which in turn seems to generate an invalid virtio request. I didn't get this in practice, I found it by code review. On the other hand, such an invalid virtio request will cause errors in QEMU and fill_balloon() also performs the same check implemented by this commit. This bug was introduced in e2250429. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org # 3.9
* | mm: correctly update zone->managed_pagesJiang Liu2013-07-031-3/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() from xen/balloon driver bacause adjust_managed_page_count() has already adjusted totalhigh_pages. This patch also fixes two bugs: 1) enhances virtio_balloon driver to adjust totalhigh_pages when reserve/unreserve pages. 2) enhance memory_hotplug.c to adjust totalhigh_pages when hot-removing memory. We still need to deal with modifications of totalram_pages in file arch/powerpc/platforms/pseries/cmm.c, but need help from PPC experts. [akpm@linux-foundation.org: remove ifdef, per Wanpeng Li, virtio_balloon.c cleanup, per Sergei] [akpm@linux-foundation.org: export adjust_managed_page_count() to modules, for drivers/virtio/virtio_balloon.c] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio_balloon: use simplified virtqueue accessors.Rusty Russell2013-03-201-3/+3
| | | | | | We never add buffers with input and output parts, so use the new accessors. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: use module_virtio_driver.Rusty Russell2013-02-131-12/+1
| | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Drivers: virtio: remove __dev* attributes.Greg Kroah-Hartman2013-01-031-2/+2
| | | | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2012-12-201-4/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio update from Rusty Russell: "Some nice cleanups, and even a patch my wife did as a "live" demo for Latinoware 2012. There's a slightly non-trivial merge in virtio-net, as we cleaned up the virtio add_buf interface while DaveM accepted the mq virtio-net patches." * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (27 commits) virtio_console: Add support for remoteproc serial virtio_console: Merge struct buffer_token into struct port_buffer virtio: add drv_to_virtio to make code clearly virtio: use dev_to_virtio wrapper in virtio virtio-mmio: Fix irq parsing in command line parameter virtio_console: Free buffers from out-queue upon close virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>( virtio_console: Use kmalloc instead of kzalloc virtio_console: Free buffer if splice fails virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0 virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0 virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0 virtio: net: make it clear that virtqueue_add_buf() no longer returns > 0 virtio: console: make it clear that virtqueue_add_buf() no longer returns > 0 virtio: make virtqueue_add_buf() returning 0 on success, not capacity. virtio: console: don't rely on virtqueue_add_buf() returning capacity. virtio_net: don't rely on virtqueue_add_buf() returning capacity. virtio-net: remove unused skb_vnet_hdr->num_sg field virtio-net: correct capacity math on ring full virtio: move queue_index and num_free fields into core struct virtqueue. ...
| * virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>(Joe Perches2012-12-181-4/+3
| | | | | | | | | | | | | | | | | | dev_<level> calls take less code than dev_printk(KERN_<LEVEL> and reducing object size is good. Convert if (printk_ratelimit()) dev_printk to dev_<level>_ratelimited. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | virtio_balloon: introduce migration primitives to balloon pagesRafael Aquini2012-12-111-19/+132
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memory fragmentation introduced by ballooning might reduce significantly the number of 2MB contiguous memory blocks that can be used within a guest, thus imposing performance penalties associated with the reduced number of transparent huge pages that could be used by the guest workload. Besides making balloon pages movable at allocation time and introducing the necessary primitives to perform balloon page migration/compaction, this patch also introduces the following locking scheme, in order to enhance the syncronization methods for accessing elements of struct virtio_balloon, thus providing protection against concurrent access introduced by parallel memory migration threads. - balloon_lock (mutex) : synchronizes the access demand to elements of struct virtio_balloon and its queue operations; [yongjun_wei@trendmicro.com.cn: fix missing unlock on error in fill_balloon()] [akpm@linux-foundation.org: avoid having multiple return points in fill_balloon()] [akpm@linux-foundation.org: fix printk warning]Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <andi@firstfloor.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio-balloon: fix add/get API useMichael S. Tsirkin2012-07-091-14/+10
| | | | | | | | | | | | | | | | | Since ee7cd8981e15bcb365fc762afe3fc47b8242f630 'virtio: expose added descriptors immediately.', in virtio balloon virtqueue_get_buf might now run concurrently with virtqueue_kick. I audited both and this seems safe in practice but this is not guaranteed by the API. Additionally, a spurious interrupt might in theory make virtqueue_get_buf run in parallel with virtqueue_add_buf, which is racy. While we might try to protect against spurious callbacks it's easier to fix the driver: balloon seems to be the only one (mis)using the API like this, so let's just fix balloon. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed unused var)
* virtio: balloon: separate out common code between remove and freeze functionsAmit Shah2012-05-221-14/+12
| | | | | | | | The remove and freeze functions have a lot of shared code; put it into a common function that gets called by both. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: drop restore_common()Amit Shah2012-05-221-6/+1
| | | | | | | | | | | | restore_common() was used when there were different thaw and freeze PM callbacks implemented. We removed thaw in commit f38f8387cbdc4138a492ce9f2a5f04fd3cd3cf33. restore_common() can be removed and virtballoon_restore() can itself do the restore ops. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: let host know of updated balloon size before module removalAmit Shah2012-05-171-0/+1
| | | | | | | | | | | | | When the balloon module is removed, we deflate the balloon, reclaiming all the pages that were given to the host. However, we don't update the config values for the new balloon size, resulting in the host showing outdated balloon values. The size update is done after each leak and fill operation, only the module removal case was left out. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: fix handling of PAGE_SIZE != 4kMichael S. Tsirkin2012-04-151-10/+41
| | | | | | | | | | | | | | | | | | | As reported by David Gibson, current code handles PAGE_SIZE != 4k completely wrong which can lead to guest memory corruption errors: - page_to_balloon_pfn is wrong: e.g. on system with 64K page size it gives the same pfn value for 16 different pages. - we also need to convert back to linux pfns when we free. - for each linux page we need to tell host about multiple balloon pages, but code only adds one pfn to the array. This patch fixes all that, tested with a 64k ppc64 kernel. Reported-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: Fix endian bugDavid Gibson2012-04-151-2/+5
| | | | | | | | | | | | | | Although virtio config space fields are usually in guest-native endian, the spec for the virtio balloon device explicitly states that both fields in its config space are little-endian. However, the current virtio_balloon driver does not have a suitable endian swap for the 'num_pages' field, although it does have one for the 'actual' field. This patch corrects the bug, adding sparse annotation while we're at it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: drop thaw PM operationAmit Shah2012-03-311-6/+0
| | | | | | | The thaw operation was used by the balloon driver, but after the last commit there's no reason to have separate thaw and restore callbacks. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio: balloon: Allow stats update after restore from S4Amit Shah2012-03-311-8/+0
| | | | | | | | | There's no reason stats update after restore can't work. If a host requested for stats, and before servicing the request, the guest entered S4, upon restore, the stats request can still be processed and sent off to the host. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio: balloon: leak / fill balloon across S4Amit Shah2012-03-011-11/+22
| | | | | | | | | | | | | | | | | | | | | | commit e562966dbaf49e7804097cd991e5d3a8934fc148 added support for S4 to the balloon driver. The freeze function did nothing to free the pages, since reclaiming the pages from the host to immediately give them back (if S4 was successful) seemed wasteful. Also, if S4 wasn't successful, the guest would have to re-fill the balloon. On restore, the pages were supposed to be marked freed and the free page counters were incremented to reflect the balloon was totally deflated. However, this wasn't done right. The pages that were earlier taken away from the guest during a balloon inflation operation were just shown as used pages after a successful restore from S4. Just a fancy way of leaking lots of memory. Instead of trying that, just leak the balloon on freeze and fill it on restore/thaw paths. This works properly now. The optimisation to not leak can be added later on after a bit of refactoring of the code. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: Add freeze, restore handlers to support S4Amit Shah2012-01-121-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handling balloon hibernate / restore is tricky. If the balloon was inflated before going into the hibernation state, upon resume, the host will not have any memory of that. Any pages that were passed on to the host earlier would most likely be invalid, and the host will have to re-balloon to the previous value to get in the pre-hibernate state. So the only sane thing for the guest to do here is to discard all the pages that were put in the balloon. When to discard the pages is the next question. One solution is to deflate the balloon just before writing the image to the disk (in the freeze() PM callback). However, asking for pages from the host just to discard them immediately after seems wasteful of resources. Hence, it makes sense to do this by just fudging our counters soon after wakeup. This means we don't deflate the balloon before sleep, and also don't put unnecessary pressure on the host. This also helps in the thaw case: if the freeze fails for whatever reason, the balloon should continue to remain in the inflated state. This was tested by issuing 'swapoff -a' and trying to go into the S4 state. That fails, and the balloon stays inflated, as expected. Both the host and the guest are happy. Finally, in the restore() callback, we empty the list of pages that were previously given off to the host, add the appropriate number of pages to the totalram_pages counter, reset the num_pages counter to 0, and all is fine. As a last step, delete the vqs on the freeze callback to prepare for hibernation, and re-create them in the restore and thaw callbacks to resume normal operation. The kthread doesn't race with any operations here, since it's frozen before the freeze() call and is thawed after the thaw() and restore() callbacks, so we're safe with that. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: Move vq initialization into separate functionAmit Shah2012-01-121-18/+30
| | | | | | | The probe and PM restore functions will share this code. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: rename virtqueue_add_buf_gfp to virtqueue_add_bufRusty Russell2012-01-121-3/+4
| | | | | | | | | Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Christoph Hellwig <hch@lst.de>
* virtio-balloon: Trivial cleanupsSasha Levin2012-01-121-3/+3
| | | | | | | | | | Trivial changes to remove forgotten junk, format comments, and correct names. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Add module.h to drivers/virtio users.Paul Gortmaker2011-10-311-0/+1
| | | | | | | | Up to now, the module.h header was as hard to keep out as sunlight. But we are cleaning that up. Fix the virtio users who simply expect module.h to be there in every C file. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* virtio balloon: kill tell-host-first logicDave Hansen2011-05-301-13/+8
| | | | | | | | | | | | | | | | | | | | | | | The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST feature bit. Whenever the bit is set, the guest kernel must always tell the host before we free pages back to the allocator. Without this feature, we might free a page (and have another user touch it) while the hypervisor is unprepared for it. But, if the bit is _not_ set, we are under no obligation to reverse the order; we're under no obligation to do _anything_. As of now, qemu-kvm defines the bit, but doesn't set it. This patch makes the "tell host first" logic the only case. This should make everybody happy, and reduce the amount of untested or untestable code in the kernel. This _also_ means that we don't have to preserve a pfn list after the pages are freed, which should let us get rid of some temporary storage (vb->pfns) eventually. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_balloon: use virtqueue_xxx wrappersMichael S. Tsirkin2010-05-191-9/+8
| | | | | | | Switch virtio_balloon to new virtqueue_xxx wrappers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Fix GFP flags passed from the virtio balloon driverBalbir Singh2010-04-221-1/+2
| | | | | | | | | | | | | | | The virtio balloon driver can dig into the reservation pools of the OS to satisfy a balloon request. This is not advisable and other balloon drivers (drivers/xen/balloon.c) avoid this as well. The patch also adds changes to avoid printing a warning if allocation fails, since we retry after sometime anyway. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: kvm <kvm@vger.kernel.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* virtio: fix balloon without VIRTIO_BALLOON_F_STATS_VQRusty Russell2010-02-241-0/+1
| | | | | | | | | | | | | | | | | | | | | When running under qemu-kvm-0.11.0: BUG: unable to handle kernel paging request at 56e58955 ... Process vballoon (pid: 1297, ti=c7976000 task=c70a6ca0 task.ti=c7 ... Call Trace: [<c88253a3>] ? balloon+0x1b3/0x440 [virtio_balloon] [<c041c2d7>] ? schedule+0x327/0x9d0 [<c88251f0>] ? balloon+0x0/0x440 [virtio_balloon] [<c014a2d4>] ? kthread+0x74/0x80 [<c014a260>] ? kthread+0x0/0x80 [<c0103b36>] ? kernel_thread_helper+0x6/0x30 need_stats_update should be zero-initialized. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Adam Litke <agl@us.ibm.com>
* virtio: Fix scheduling while atomic in virtio_balloon statsAdam Litke2010-02-241-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | This is a fix for my earlier patch: "virtio: Add memory statistics reporting to the balloon driver (V4)". I discovered that all_vm_events() can sleep and therefore stats collection cannot be done in interrupt context. One solution is to handle the interrupt by noting that stats need to be collected and waking the existing vballoon kthread which will complete the work via stats_handle_request(). Rusty, is this a saner way of doing business? There is one issue that I would like a broader opinion on. In stats_request, I update vb->need_stats_update and then wake up the kthread. The kthread uses vb->need_stats_update as a condition variable. Do I need a memory barrier between the update and wake_up to ensure that my kthread sees the correct value? My testing suggests that it is not needed but I would like some confirmation from the experts. Signed-off-by: Adam Litke <agl@us.ibm.com> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Add memory statistics reporting to the balloon driver (V4)Adam Litke2010-02-241-8/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor fixes)
* virtio: fix section mismatch warningsJeff Mahoney2010-01-161-3/+3
| | | | | | | | | | | | | | Fix fixes the following warnings by renaming the driver structures to be suffixed with _driver. WARNING: drivers/virtio/virtio_balloon.o(.data+0x88): Section mismatch in reference from the variable virtio_balloon to the function .devexit.text:virtballoon_remove() WARNING: drivers/char/hw_random/virtio-rng.o(.data+0x88): Section mismatch in reference from the variable virtio_rng to the function .devexit.text:virtrng_remove() Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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