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path: root/drivers/virtio/virtio_balloon.c
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2021-09-06virtio-balloon: Use virtio_find_vqs() helperXianting Tian
Use the helper virtio_find_vqs(). Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210723054259.2779-1-xianting.tian@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-06-29virtio_balloon: specify page reporting order if neededGavin Shan
The page reporting won't be triggered if the freeing page can't come up with a free area, whose size is equal or bigger than the threshold (page reporting order). The default page reporting order, equal to @pageblock_order, is too huge on some architectures to trigger page reporting. One example is ARM64 when 64KB base page size is used. PAGE_SIZE: 64KB pageblock_order: 13 (512MB) MAX_ORDER: 14 This specifies the page reporting order to 5 (2MB) for this specific case so that page reporting can be triggered. Link: https://lkml.kernel.org/r/20210625014710.42954-5-gshan@redhat.com Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-03virtio-balloon: fix a typo in comment of virtballoon_migratepage()Liu Xiang
Typo: compation --> compaction Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com> Link: https://lore.kernel.org/r/20210327031710.16151-1-liu.xiang@zlingsmart.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-12-15mm, page_poison: remove CONFIG_PAGE_POISONING_NO_SANITYVlastimil Babka
CONFIG_PAGE_POISONING_NO_SANITY skips the check on page alloc whether the poison pattern was corrupted, suggesting a use-after-free. The motivation to introduce it in commit 8823b1dbc05f ("mm/page_poison.c: enable PAGE_POISONING as a separate option") was to simply sanitize freed pages, optimally together with CONFIG_PAGE_POISONING_ZERO. These days we have an init_on_free=1 boot option, which makes this use case of page poisoning redundant. For sanitizing, writing zeroes is sufficient, there is pretty much no benefit from writing the 0xAA poison pattern to freed pages, without checking it back on alloc. Thus, remove this option and suggest init_on_free instead in the main config's help. Link: https://lkml.kernel.org/r/20201113104033.22907-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <labbott@kernel.org> Cc: Mateusz Nosek <mateusznosek0@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm, page_poison: use static key more efficientlyVlastimil Babka
Commit 11c9c7edae06 ("mm/page_poison.c: replace bool variable with static key") changed page_poisoning_enabled() to a static key check. However, the function is not inlined, so each check still involves a function call with overhead not eliminated when page poisoning is disabled. Analogically to how debug_pagealloc is handled, this patch converts page_poisoning_enabled() back to boolean check, and introduces page_poisoning_enabled_static() for fast paths. Both functions are inlined. The function kernel_poison_pages() is also called unconditionally and does the static key check inside. Remove it from there and put it to callers. Also split it to two functions kernel_poison_pages() and kernel_unpoison_pages() instead of the confusing bool parameter. Also optimize the check that enables page poisoning instead of debug_pagealloc for architectures without proper debug_pagealloc support. Move the check to init_mem_debugging_and_hardening() to enable a single static key instead of having two static branches in page_poisoning_enabled_static(). Link: https://lkml.kernel.org/r/20201113104033.22907-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <labbott@kernel.org> Cc: Mateusz Nosek <mateusznosek0@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-21virtio-balloon: Constify id_tableRikard Falkeborn
id_table is not modified, so make it const to allow the compiler to put it in read-only memory. Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Link: https://lore.kernel.org/r/20200911203509.26505-2-rikard.falkeborn@gmail.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-08-05virtio_balloon: use LE config space accessesMichael S. Tsirkin
Balloon is LE, it's cleaner to access it as such directly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_balloon: fix sparse warningMichael S. Tsirkin
balloon uses virtio32_to_cpu instead of cpu_to_virtio32 to convert a native endian number to virtio. No practical difference but makes sparse warn. Fix it up. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2020-08-03virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORMMichael S. Tsirkin
Rename the bit to match latest virtio spec. Add a compat macro to avoid breaking existing userspace. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-07-29virtio_balloon: fix up endian-ness for free cmd idMichael S. Tsirkin
free cmd id is read using virtio endian, spec says all fields in balloon are LE. Fix it up. Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-07-29virtio-balloon: Document byte ordering of poison_valAlexander Duyck
The poison_val field in the virtio_balloon_config is treated as a little-endian field by the host. Since we are currently only having to deal with a single byte poison value this isn't a problem, however if the value should ever expand it would cause byte ordering issues. Document that in the code so that we know that if the value should ever expand we need to byte swap the value on big-endian architectures. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200713203539.17140.71425.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-06-04virtio-balloon: Disable free page reporting if page poison reporting is not ↵Alexander Duyck
enabled We should disable free page reporting if page poisoning is enabled but we cannot report it via the balloon interface. This way we can avoid the possibility of corrupting guest memory. Normally the page poisoning feature should always be present when free page reporting is enabled on the hypervisor, however this allows us to correctly handle a case of the virtio-balloon device being possibly misconfigured. Fixes: 5d757c8d518d ("virtio-balloon: add support for providing free page reports to host") Cc: stable@vger.kernel.org Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200508173732.17877.85060.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17virtio-balloon: Avoid using the word 'report' when referring to free page ↵Alexander Duyck
hinting It can be confusing to have multiple features within the same driver that are using the same verbage. As such this patch is creating a union of free_page_report_cmd_id with free_page_hint_cmd_id so that we can clean-up the userspace code a bit in terms of readability while maintaining the functionality of legacy code. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200415174318.13597.99753.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17virtio-balloon: make virtballoon_free_page_report() staticJason Yan
Fix the following sparse warning: drivers/virtio/virtio_balloon.c:168:5: warning: symbol 'virtballoon_free_page_report' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20200409085047.45483-1-yanaijie@huawei.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-07virtio-balloon: switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOMDavid Hildenbrand
Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some other slab cache that should be shrunk when under memory pressure. The shrinker does not have a concept of priorities yet, so this behavior cannot be configured. Eventually once that is in place, we might want to switch back after doing proper testing. There was a report that this results in undesired side effects when inflating the balloon to shrink the page cache. [1] "When inflating the balloon against page cache (i.e. no free memory remains) vmscan.c will both shrink page cache, but also invoke the shrinkers -- including the balloon's shrinker. So the balloon driver allocates memory which requires reclaim, vmscan gets this memory by shrinking the balloon, and then the driver adds the memory back to the balloon. Basically a busy no-op." The name "deflate on OOM" makes it pretty clear when deflation should happen - after other approaches to reclaim memory failed, not while reclaiming. This allows to minimize the footprint of a guest - memory will only be taken out of the balloon when really needed. Keep using the shrinker for VIRTIO_BALLOON_F_FREE_PAGE_HINT, because this has no such side effects. Always register the shrinker with VIRTIO_BALLOON_F_FREE_PAGE_HINT now. We are always allowed to reuse free pages that are still to be processed by the guest. The hypervisor takes care of identifying and resolving possible races between processing a hinting request and the guest reusing a page. In contrast to pre commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker"), don't add a module parameter to configure the number of pages to deflate on OOM. Can be re-added if really needed. Also, pay attention that leak_balloon() returns the number of 4k pages - convert it properly in virtio_balloon_oom_notify(). Testing done by Tyler for future reference: Test setup: VM with 16 CPU, 64GB RAM. Running Debian 10. We have a 42 GB file full of random bytes that we continually cat to /dev/null. This fills the page cache as the file is read. Meanwhile, we trigger the balloon to inflate, with a target size of 53 GB. This setup causes the balloon inflation to pressure the page cache as the page cache is also trying to grow. Afterwards we shrink the balloon back to zero (so total deflate == total inflate). Without this patch (kernel 4.19.0-5): Inflation never reaches the target until we stop the "cat file > /dev/null" process. Total inflation time was 542 seconds. The longest period that made no net forward progress was 315 seconds. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 154828377 balloon_deflate 154828377 With this patch (kernel 5.6.0-rc4+): Total inflation duration was 63 seconds. No deflate-queue activity occurs when pressuring the page-cache. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 12968539 balloon_deflate 12968539 Conclusion: This patch fixes the issue. In the test it reduced inflate/deflate activity by 12x, and reduced inflation time by 8.6x. But more importantly, if we hadn't killed the "cat file > /dev/null" process then, without the patch, the inflation process would never reach the target. [1] https://www.spinics.net/lists/linux-virtualization/msg40863.html Link: http://lkml.kernel.org/r/20200311135523.18512-2-david@redhat.com Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Tyler Sanderson <tysand@google.com> Tested-by: Tyler Sanderson <tysand@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Nadav Amit <namit@vmware.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: add support for providing free page reports to hostAlexander Duyck
Add support for the page reporting feature provided by virtio-balloon. Reporting differs from the regular balloon functionality in that is is much less durable than a standard memory balloon. Instead of creating a list of pages that cannot be accessed the pages are only inaccessible while they are being indicated to the virtio interface. Once the interface has acknowledged them they are placed back into their respective free lists and are once again accessible by the guest system. Unlike a standard balloon we don't inflate and deflate the pages. Instead we perform the reporting, and once the reporting is completed it is assumed that the page has been dropped from the guest and will be faulted back in the next time the page is accessed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: pull page poisoning config out of free page hintingAlexander Duyck
Currently the page poisoning setting wasn't being enabled unless free page hinting was enabled. However we will need the page poisoning tracking logic as well for free page reporting. As such pull it out and make it a separate bit of config in the probe function. In addition we need to add support for the more recent init_on_free feature which expects a behavior similar to page poisoning in that we expect the page to be pre-zeroed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224646.29318.695.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-08virtio_balloon: Adjust label in virtballoon_probeNathan Chancellor
Clang warns when CONFIG_BALLOON_COMPACTION is unset: ../drivers/virtio/virtio_balloon.c:963:1: warning: unused label 'out_del_vqs' [-Wunused-label] out_del_vqs: ^~~~~~~~~~~~ 1 warning generated. Move the label within the preprocessor block since it is only used when CONFIG_BALLOON_COMPACTION is set. Fixes: 1ad6f58ea936 ("virtio_balloon: Fix memory leaks on errors in virtballoon_probe()") Link: https://github.com/ClangBuiltLinux/linux/issues/886 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20200216004039.23464-1-natechancellor@gmail.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-02-06virtio_balloon: Fix memory leaks on errors in virtballoon_probe()David Hildenbrand
We forget to put the inode and unmount the kernfs used for compaction. Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Liang Li <liang.z.li@intel.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200205163402.42627-3-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-06virtio-balloon: Fix memory leak when unloading while hinting is in progressDavid Hildenbrand
When unloading the driver while hinting is in progress, we will not release the free page blocks back to MM, resulting in a memory leak. Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Liang Li <liang.z.li@intel.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200205163402.42627-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-06virtio_balloon: prevent pfn array overflowMichael S. Tsirkin
Make sure, at build time, that pfn array is big enough to hold a single page. It happens to be true since the PAGE_SHIFT value at the moment is 20, which is 1M - exactly 256 4K balloon pages. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-02-06virtio-balloon: initialize all vq callbacksDaniel Verkamp
Ensure that elements of the callbacks array that correspond to unavailable features are set to NULL; previously, they would be left uninitialized. Since the corresponding names array elements were explicitly set to NULL, the uninitialized callback pointers would not actually be dereferenced; however, the uninitialized callbacks elements would still be read in vp_find_vqs_msix() and used to calculate the number of MSI-X vectors required. Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-12-11virtio_balloon: divide/multiply instead of shiftsMichael S. Tsirkin
We managed to get confused about the shift direction at least once. Let's switch to division/multiplcation instead. Add a number of pages macro for this purpose. We still keep the order macro around too since this is what alloc/free pages want. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-12-11virtio_balloon: name cleanupsMichael S. Tsirkin
free_page_order is a confusing name. It's not a page order actually, it's the order of the block of memory we are hinting. Rename to hint_block_order. Also, rename SIZE to BYTES to make it clear it's the block size in bytes. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-12-11virtio-balloon: fix managed page counts when migrating pages between zonesDavid Hildenbrand
In case we have to migrate a ballon page to a newpage of another zone, the managed page count of both zones is wrong. Paired with memory offlining (which will adjust the managed page count), we can trigger kernel crashes and all kinds of different symptoms. One way to reproduce: 1. Start a QEMU guest with 4GB, no NUMA 2. Hotplug a 1GB DIMM and online the memory to ZONE_NORMAL 3. Inflate the balloon to 1GB 4. Unplug the DIMM (be quick, otherwise unmovable data ends up on it) 5. Observe /proc/zoneinfo Node 0, zone Normal pages free 16810 min 24848885473806 low 18471592959183339 high 36918337032892872 spanned 262144 present 262144 managed 18446744073709533486 6. Do anything that requires some memory (e.g., inflate the balloon some more). The OOM goes crazy and the system crashes [ 238.324946] Out of memory: Killed process 537 (login) total-vm:27584kB, anon-rss:860kB, file-rss:0kB, shmem-rss:00 [ 238.338585] systemd invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0 [ 238.339420] CPU: 0 PID: 1 Comm: systemd Tainted: G D W 5.4.0-next-20191204+ #75 [ 238.340139] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu4 [ 238.341121] Call Trace: [ 238.341337] dump_stack+0x8f/0xd0 [ 238.341630] dump_header+0x61/0x5ea [ 238.341942] oom_kill_process.cold+0xb/0x10 [ 238.342299] out_of_memory+0x24d/0x5a0 [ 238.342625] __alloc_pages_slowpath+0xd12/0x1020 [ 238.343024] __alloc_pages_nodemask+0x391/0x410 [ 238.343407] pagecache_get_page+0xc3/0x3a0 [ 238.343757] filemap_fault+0x804/0xc30 [ 238.344083] ? ext4_filemap_fault+0x28/0x42 [ 238.344444] ext4_filemap_fault+0x30/0x42 [ 238.344789] __do_fault+0x37/0x1a0 [ 238.345087] __handle_mm_fault+0x104d/0x1ab0 [ 238.345450] handle_mm_fault+0x169/0x360 [ 238.345790] do_user_addr_fault+0x20d/0x490 [ 238.346154] do_page_fault+0x31/0x210 [ 238.346468] async_page_fault+0x43/0x50 [ 238.346797] RIP: 0033:0x7f47eba4197e [ 238.347110] Code: Bad RIP value. [ 238.347387] RSP: 002b:00007ffd7c0c1890 EFLAGS: 00010293 [ 238.347834] RAX: 0000000000000002 RBX: 000055d196a20a20 RCX: 00007f47eba4197e [ 238.348437] RDX: 0000000000000033 RSI: 00007ffd7c0c18c0 RDI: 0000000000000004 [ 238.349047] RBP: 00007ffd7c0c1c20 R08: 0000000000000000 R09: 0000000000000033 [ 238.349660] R10: 00000000ffffffff R11: 0000000000000293 R12: 0000000000000001 [ 238.350261] R13: ffffffffffffffff R14: 0000000000000000 R15: 00007ffd7c0c18c0 [ 238.350878] Mem-Info: [ 238.351085] active_anon:3121 inactive_anon:51 isolated_anon:0 [ 238.351085] active_file:12 inactive_file:7 isolated_file:0 [ 238.351085] unevictable:0 dirty:0 writeback:0 unstable:0 [ 238.351085] slab_reclaimable:5565 slab_unreclaimable:10170 [ 238.351085] mapped:3 shmem:111 pagetables:155 bounce:0 [ 238.351085] free:720717 free_pcp:2 free_cma:0 [ 238.353757] Node 0 active_anon:12484kB inactive_anon:204kB active_file:48kB inactive_file:28kB unevictable:0kB iss [ 238.355979] Node 0 DMA free:11556kB min:36kB low:48kB high:60kB reserved_highatomic:0KB active_anon:152kB inactivB [ 238.358345] lowmem_reserve[]: 0 2955 2884 2884 2884 [ 238.358761] Node 0 DMA32 free:2677864kB min:7004kB low:10028kB high:13052kB reserved_highatomic:0KB active_anon:0B [ 238.361202] lowmem_reserve[]: 0 0 72057594037927865 72057594037927865 72057594037927865 [ 238.361888] Node 0 Normal free:193448kB min:99395541895224kB low:73886371836733356kB high:147673348131571488kB reB [ 238.364765] lowmem_reserve[]: 0 0 0 0 0 [ 238.365101] Node 0 DMA: 7*4kB (U) 5*8kB (UE) 6*16kB (UME) 2*32kB (UM) 1*64kB (U) 2*128kB (UE) 3*256kB (UME) 2*512B [ 238.366379] Node 0 DMA32: 0*4kB 1*8kB (U) 2*16kB (UM) 2*32kB (UM) 2*64kB (UM) 1*128kB (U) 1*256kB (U) 1*512kB (U)B [ 238.367654] Node 0 Normal: 1985*4kB (UME) 1321*8kB (UME) 844*16kB (UME) 524*32kB (UME) 300*64kB (UME) 138*128kB (B [ 238.369184] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [ 238.369915] 130 total pagecache pages [ 238.370241] 0 pages in swap cache [ 238.370533] Swap cache stats: add 0, delete 0, find 0/0 [ 238.370981] Free swap = 0kB [ 238.371239] Total swap = 0kB [ 238.371488] 1048445 pages RAM [ 238.371756] 0 pages HighMem/MovableOnly [ 238.372090] 306992 pages reserved [ 238.372376] 0 pages cma reserved [ 238.372661] 0 pages hwpoisoned In another instance (older kernel), I was able to observe this (negative page count :/): [ 180.896971] Offlined Pages 32768 [ 182.667462] Offlined Pages 32768 [ 184.408117] Offlined Pages 32768 [ 186.026321] Offlined Pages 32768 [ 187.684861] Offlined Pages 32768 [ 189.227013] Offlined Pages 32768 [ 190.830303] Offlined Pages 32768 [ 190.833071] Built 1 zonelists, mobility grouping on. Total pages: -36920272750453009 In another instance (older kernel), I was no longer able to start any process: [root@vm ~]# [ 214.348068] Offlined Pages 32768 [ 215.973009] Offlined Pages 32768 cat /proc/meminfo -bash: fork: Cannot allocate memory [root@vm ~]# cat /proc/meminfo -bash: fork: Cannot allocate memory Fix it by properly adjusting the managed page count when migrating if the zone changed. The managed page count of the zones now looks after unplug of the DIMM (and after deflating the balloon) just like before inflating the balloon (and plugging+onlining the DIMM). We'll temporarily modify the totalram page count. If this ever becomes a problem, we can fine tune by providing helpers that don't touch the totalram pages (e.g., adjust_zone_managed_page_count()). Please note that fixing up the managed page count is only necessary when we adjusted the managed page count when inflating - only if we don't have VIRTIO_BALLOON_F_DEFLATE_ON_OOM. With that feature, the managed page count is not touched when inflating/deflating. Reported-by: Yumei Huang <yuhuang@redhat.com> Fixes: 3dcc0571cd64 ("mm: correctly update zone->managed_pages") Cc: <stable@vger.kernel.org> # v3.11+ Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: virtualization@lists.linux-foundation.org Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-11-20virtio_balloon: fix shrinker countWei Wang
Instead of multiplying by page order, virtio balloon divided by page order. The result is that it can return 0 if there are a bit less than MAX_ORDER - 1 pages in use, and then shrinker scan won't be called. Cc: stable@vger.kernel.org Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-11-20virtio_balloon: fix shrinker scan number of pagesMichael S. Tsirkin
virtio_balloon_shrinker_scan should return number of system pages freed, but because it's calling functions that deal with balloon pages, it gets confused and sometimes returns the number of balloon pages. It does not matter practically as the exact number isn't used, but it seems better to be consistent in case someone starts using this API. Further, if we ever tried to iteratively leak pages as virtio_balloon_shrinker_scan tries to do, we'd run into issues - this is because freed_pages was accumulating total freed pages, but was also subtracted on each iteration from pages_to_free, which can result in either leaking less memory than we were supposed to free, or more if pages_to_free underruns. On a system with 4K pages we are lucky that we are never asked to leak more than 128 pages while we can leak up to 256 at a time, but it looks like a real issue for systems with page size != 4K. Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Reported-by: Khazhismel Kumykov <khazhy@google.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-07-19Merge branch 'work.mount0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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() ...
2019-05-25vfs: Convert virtio_balloon to use the new mount APIDavid Howells
Convert the virtio_balloon filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: David Howells <dhowells@redhat.com> cc: "Michael S. Tsirkin" <mst@redhat.com> cc: Jason Wang <jasowang@redhat.com> cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25mount_pseudo(): drop 'name' argument, switch to d_make_root()Al Viro
Once upon a time we used to set ->d_name of e.g. pipefs root so that d_path() on pipes would work. These days it's completely pointless - dentries of pipes are not even connected to pipefs root. However, mount_pseudo() had set the root dentry name (passed as the second argument) and callers kept inventing names to pass to it. Including those that didn't *have* any non-root dentries to start with... All of that had been pointless for about 8 years now; it's time to get rid of that cargo-culting... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 50 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-20balloon: don't bother with dentry_operationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-06virtio_balloon: remove the unnecessary 0-initializationWei Wang
We've changed to kzalloc the vb struct, so no need to 0-initialize this field one more time. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2019-03-06virtio-balloon: improve update_balloon_size_funcWei Wang
There is no need to update the balloon actual register when there is no ballooning request. This patch avoids update_balloon_size when diff is 0. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-01-14virtio-balloon: tweak config_changed implementationWei Wang
virtio-ccw has deadlock issues with reading the config space inside the interrupt context, so we tweak the virtballoon_changed implementation by moving the config read operations into the related workqueue contexts. The config_read_bitmap is used as a flag to the workqueue callbacks about the related config fields that need to be read. The cmd_id_received is also renamed to cmd_id_received_cache, and the value should be obtained via virtio_balloon_cmd_id_received. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-10-24virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISONWei Wang
The VIRTIO_BALLOON_F_PAGE_POISON feature bit is used to indicate if the guest is using page poisoning. Guest writes to the poison_val config field to tell host about the page poisoning value that is in use. Suggested-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-10-24virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINTWei Wang
Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the support of reporting hints of guest free pages to host via virtio-balloon. Currenlty, only free page blocks of MAX_ORDER - 1 are reported. They are obtained one by one from the mm free list via the regular allocation function. Host requests the guest to report free page hints by sending a new cmd id to the guest via the free_page_report_cmd_id configuration register. When the guest starts to report, it first sends a start cmd to host via the free page vq, which acks to host the cmd id received. When the guest finishes reporting free pages, a stop cmd is sent to host via the vq. Host may also send a stop cmd id to the guest to stop the reporting. VIRTIO_BALLOON_CMD_ID_STOP: Host sends this cmd to stop the guest reporting. VIRTIO_BALLOON_CMD_ID_DONE: Host sends this cmd to tell the guest that the reported pages are ready to be freed. Why does the guest free the reported pages when host tells it is ready to free? This is because freeing pages appears to be expensive for live migration. free_pages() dirties memory very quickly and makes the live migraion not converge in some cases. So it is good to delay the free_page operation when the migration is done, and host sends a command to guest about that. Why do we need the new VIRTIO_BALLOON_CMD_ID_DONE, instead of reusing VIRTIO_BALLOON_CMD_ID_STOP? This is because live migration is usually done in several rounds. At the end of each round, host needs to send a VIRTIO_BALLOON_CMD_ID_STOP cmd to the guest to stop (or say pause) the reporting. The guest resumes the reporting when it receives a new command id at the beginning of the next round. So we need a new cmd id to distinguish between "stop reporting" and "ready to free the reported pages". TODO: - Add a batch page allocation API to amortize the allocation overhead. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Liang Li <liang.z.li@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-08-22virtio_balloon: replace oom notifier with shrinkerWei Wang
The OOM notifier is getting deprecated to use for the reasons: - As a callout from the oom context, it is too subtle and easy to generate bugs and corner cases which are hard to track; - It is called too late (after the reclaiming has been performed). Drivers with large amuont of reclaimable memory is expected to release them at an early stage of memory pressure; - The notifier callback isn't aware of oom contrains; Link: https://lkml.org/lkml/2018/7/12/314 This patch replaces the virtio-balloon oom notifier with a shrinker to release balloon pages on memory pressure. The balloon pages are given back to mm adaptively by returning the number of pages that the reclaimer is asking for (i.e. sc->nr_to_scan). Currently the max possible value of sc->nr_to_scan passed to the balloon shrinker is SHRINK_BATCH, which is 128. This is smaller than the limitation that only VIRTIO_BALLOON_ARRAY_PFNS_MAX (256) pages can be returned via one invocation of leak_balloon. But this patch still considers the case that SHRINK_BATCH or shrinker->batch could be changed to a value larger than VIRTIO_BALLOON_ARRAY_PFNS_MAX, which will need to do multiple invocations of leak_balloon. Historically, the feature VIRTIO_BALLOON_F_DEFLATE_ON_OOM has been used to release balloon pages on OOM. We continue to use this feature bit for the shrinker, so the shrinker is only registered when this feature bit has been negotiated with host. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-08-22virtio-balloon: kzalloc the vb structWei Wang
Zero all the vb fields at alloaction, so that we don't need to zero-initialize each field one by one later. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-08-22virtio-balloon: remove BUG() in init_vqsWei Wang
It's a bit overkill to use BUG when failing to add an entry to the stats_vq in init_vqs. So remove it and just return the error to the caller to bail out nicely. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-07-30virtio_balloon: fix another race between migration and ballooningJiang Biao
Kernel panic when with high memory pressure, calltrace looks like, PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java" #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30 #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8 #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46 #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc #6 [ffff881ec7ed7838] __node_set at ffffffff81680300 #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5 #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8 [exception RIP: _raw_spin_lock_irqsave+47] RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8 RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008 RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098 R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 It happens in the pagefault and results in double pagefault during compacting pages when memory allocation fails. Analysed the vmcore, the page leads to second pagefault is corrupted with _mapcount=-256, but private=0. It's caused by the race between migration and ballooning, and lock missing in virtballoon_migratepage() of virtio_balloon driver. This patch fix the bug. Fixes: e22504296d4f64f ("virtio_balloon: introduce migration primitives to balloon pages") Cc: stable@vger.kernel.org Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Huang Chong <huang.chong@zte.com.cn> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-04-10virtio_balloon: export hugetlb page allocation countsJonathan Helman
Export the number of successful and failed hugetlb page allocations via the virtio balloon driver. These 2 counts come directly from the vm_events HTLB_BUDDY_PGALLOC and HTLB_BUDDY_PGALLOC_FAIL. Signed-off-by: Jonathan Helman <jonathan.helman@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com>
2018-01-31virtio_balloon: include disk/file caches memory statisticsTomáš Golembiovský
Add a new field VIRTIO_BALLOON_S_CACHES to virtio_balloon memory statistics protocol. The value represents all disk/file caches. In this case it corresponds to the sum of values Buffers+Cached+SwapCached from /proc/meminfo. Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-12-01virtio_balloon: fix increment of vb->num_pfns in fill_balloon()Jan Stancek
commit c7cdff0e8647 ("virtio_balloon: fix deadlock on OOM") changed code to increment vb->num_pfns before call to set_page_pfns(), which used to happen only after. This patch fixes boot hang for me on ppc64le KVM guests. Fixes: c7cdff0e8647 ("virtio_balloon: fix deadlock on OOM") Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-11-14virtio_balloon: fix deadlock on OOMMichael S. Tsirkin
fill_balloon doing memory allocations under balloon_lock can cause a deadlock when leak_balloon is called from virtballoon_oom_notify and tries to take same lock. To fix, split page allocation and enqueue and do allocations outside the lock. Here's a detailed analysis of the deadlock by Tetsuo Handa: In leak_balloon(), mutex_lock(&vb->balloon_lock) is called in order to serialize against fill_balloon(). But in fill_balloon(), alloc_page(GFP_HIGHUSER[_MOVABLE] | __GFP_NOMEMALLOC | __GFP_NORETRY) is called with vb->balloon_lock mutex held. Since GFP_HIGHUSER[_MOVABLE] implies __GFP_DIRECT_RECLAIM | __GFP_IO | __GFP_FS, despite __GFP_NORETRY is specified, this allocation attempt might indirectly depend on somebody else's __GFP_DIRECT_RECLAIM memory allocation. And such indirect __GFP_DIRECT_RECLAIM memory allocation might call leak_balloon() via virtballoon_oom_notify() via blocking_notifier_call_chain() callback via out_of_memory() when it reached __alloc_pages_may_oom() and held oom_lock mutex. Since vb->balloon_lock mutex is already held by fill_balloon(), it will cause OOM lockup. Thread1 Thread2 fill_balloon() takes a balloon_lock balloon_page_enqueue() alloc_page(GFP_HIGHUSER_MOVABLE) direct reclaim (__GFP_FS context) takes a fs lock waits for that fs lock alloc_page(GFP_NOFS) __alloc_pages_may_oom() takes the oom_lock out_of_memory() blocking_notifier_call_chain() leak_balloon() tries to take that balloon_lock and deadlocks Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-07-25virtio-balloon: coding format cleanupWei Wang
Clean up the comment format. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-07-25virtio-balloon: deflate via a page listLiang Li
This patch saves the deflated pages to a list, instead of the PFN array. Accordingly, the balloon_pfn_to_page() function is removed. Signed-off-by: Liang Li <liang.z.li@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-06-18virtio_balloon: disable VIOMMU supportMichael S. Tsirkin
virtio balloon bypasses the DMA API entirely so does not support the VIOMMU right now. It's not clear we need that support, for now let's just make sure we don't pretend to support it. Cc: stable@vger.kernel.org Cc: Wei Wang <wei.w.wang@intel.com> Fixes: 1a937693993f ("virtio: new feature to detect IOMMU device quirk") Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2017-05-02virtio: wrap find_vqsMichael S. Tsirkin
We are going to add more parameters to find_vqs, let's wrap the call so we don't need to tweak all drivers every time. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-28virtio_balloon: prevent uninitialized variable useArnd Bergmann
The latest gcc-7.0.1 snapshot reports a new warning: virtio/virtio_balloon.c: In function 'update_balloon_stats': virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:260:26: error: 'events[3]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:261:56: error: 'events[18]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:262:56: error: 'events[17]' is used uninitialized in this function [-Werror=uninitialized] This seems absolutely right, so we should add an extra check to prevent copying uninitialized stack data into the statistics. >From all I can tell, this has been broken since the statistics code was originally added in 2.6.34. Fixes: 9564e138b1f6 ("virtio: Add memory statistics reporting to the balloon driver (V4)") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>