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2022-04-20Drivers: hv: balloon: Disable balloon and hot-add accordinglyBoqun Feng1-2/+34
[ Upstream commit be5802795cf8d0b881745fa9ba7790293b382280 ] Currently there are known potential issues for balloon and hot-add on ARM64: * Unballoon requests from Hyper-V should only unballoon ranges that are guest page size aligned, otherwise guests cannot handle because it's impossible to partially free a page. This is a problem when guest page size > 4096 bytes. * Memory hot-add requests from Hyper-V should provide the NUMA node id of the added ranges or ARM64 should have a functional memory_add_physaddr_to_nid(), otherwise the node id is missing for add_memory(). These issues require discussions on design and implementation. In the meanwhile, post_status() is working and essential to guest monitoring. Therefore instead of disabling the entire hv_balloon driver, the ballooning (when page size > 4096 bytes) and hot-add are disabled accordingly for now. Once the issues are fixed, they can be re-enable in these cases. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20220325023212.1570049-3-boqun.feng@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08hv_balloon: rate-limit "Unhandled message" warningAnssi Hannula1-1/+1
[ Upstream commit 1d7286729aa616772be334eb908e11f527e1e291 ] For a couple of times I have encountered a situation where hv_balloon: Unhandled message: type: 12447 is being flooded over 1 million times per second with various values, filling the log and consuming cycles, making debugging difficult. Add rate limiting to the message. Most other Hyper-V drivers already have similar rate limiting in their message callbacks. The cause of the floods in my case was probably fixed by 96d9d1fa5cd5 ("Drivers: hv: balloon: account for vmbus packet header in max_pkt_size"). Fixes: 9aa8b50b2b3d ("Drivers: hv: Add Hyper-V balloon driver") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20220222141400.98160-1-anssi.hannula@bitwise.fi Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-01Drivers: hv: balloon: account for vmbus packet header in max_pkt_sizeYanming Liu1-0/+7
[ Upstream commit 96d9d1fa5cd505078534113308ced0aa56d8da58 ] Commit adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer") introduced a notion of maximum packet size in vmbus channel and used that size to initialize a buffer holding all incoming packet along with their vmbus packet header. hv_balloon uses the default maximum packet size VMBUS_DEFAULT_MAX_PKT_SIZE which matches its maximum message size, however vmbus_open expects this size to also include vmbus packet header. This leads to 4096 bytes dm_unballoon_request messages being truncated to 4080 bytes. When the driver tries to read next packet it starts from a wrong read_index, receives garbage and prints a lot of "Unhandled message: type: <garbage>" in dmesg. Allocate the buffer with HV_HYP_PAGE_SIZE more bytes to make room for the header. Fixes: adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer") Suggested-by: Michael Kelley (LINUX) <mikelley@microsoft.com> Suggested-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Yanming Liu <yanminglr@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20220119202052.3006981-1-yanminglr@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-25Drivers: hv: balloon: Use VMBUS_RING_SIZE() wrapper for dm_ring_sizeBoqun Feng1-1/+1
commit 8a7eb2d476c6823cd44d8c25a6230a52417d7ef8 upstream. Baihua reported an error when boot an ARM64 guest with PAGE_SIZE=64k and BALLOON is enabled: hv_vmbus: registering driver hv_balloon hv_vmbus: probe failed for device 1eccfd72-4b41-45ef-b73a-4a6e44c12924 (-22) The cause of this is that the ringbuffer size for hv_balloon is not adjusted with VMBUS_RING_SIZE(), which makes the size not large enough for ringbuffers on guest with PAGE_SIZE=64k. Therefore use VMBUS_RING_SIZE() to calculate the ringbuffer size. Note that the old size (20 * 1024) counts a 4k header in the total size, while VMBUS_RING_SIZE() expects the parameter as the payload size, so use 16 * 1024. Cc: <stable@vger.kernel.org> # 5.15.x Reported-by: Baihua Lu <baihua.lu@microsoft.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20211101150026.736124-1-boqun.feng@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14hv_balloon: Remove redundant assignment to region_startJiapeng Chong1-1/+0
Variable region_start is set to pg_start but this value is never read as it is overwritten later on, hence it is a redundant assignment and can be removed. Cleans up the following clang-analyzer warning: drivers/hv/hv_balloon.c:1013:3: warning: Value stored to 'region_start' is never read [clang-analyzer-deadcode.DeadStores]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/1619691681-86256-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-24x86/Hyper-V: Support for free page reportingSunil Muthuswamy1-0/+89
Linux has support for free page reporting now (36e66c554b5c) for virtualized environment. On Hyper-V when virtually backed VMs are configured, Hyper-V will advertise cold memory discard capability, when supported. This patch adds the support to hook into the free page reporting infrastructure and leverage the Hyper-V cold memory discard hint hypercall to report/free these pages back to the host. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Tested-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-26mm/memory_hotplug: MEMHP_MERGE_RESOURCE -> MHP_MERGE_RESOURCEDavid Hildenbrand1-1/+1
Let's make "MEMHP_MERGE_RESOURCE" consistent with "MHP_NONE", "mhp_t" and "mhp_flags". As discussed recently [1], "mhp" is our internal acronym for memory hotplug now. [1] https://lore.kernel.org/linux-mm/c37de2d0-28a1-4f7d-f944-cfd7d81c334d@redhat.com/ Link: https://lkml.kernel.org/r/20210126115829.10909-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-13hv_balloon: do adjust_managed_page_count() when ballooning/un-ballooningVitaly Kuznetsov1-1/+4
Unlike virtio_balloon/virtio_mem/xen balloon drivers, Hyper-V balloon driver does not adjust managed pages count when ballooning/un-ballooning and this leads to incorrect stats being reported, e.g. unexpected 'free' output. Note, the calculation in post_status() seems to remain correct: ballooned out pages are never 'available' and we manually add dm->num_pages_ballooned to 'commited'. Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201202161245.2406143-3-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-13hv_balloon: simplify math in alloc_balloon_pages()Vitaly Kuznetsov1-1/+1
'alloc_unit' in alloc_balloon_pages() is either '512' for 2M allocations or '1' for 4k allocations. So 1 << get_order(alloc_unit << PAGE_SHIFT) equals to 'alloc_unit' and the for loop basically sets all them offline. Simplify the math to improve the readability. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201202161245.2406143-2-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-05Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
2020-10-19hv_balloon: disable warning when floor reachedOlaf Hering1-1/+1
It is not an error if the host requests to balloon down, but the VM refuses to do so. Without this change a warning is logged in dmesg every five minutes. Fixes: b3bb97b8a49f3 ("Drivers: hv: balloon: Add logging for dynamic memory operations") Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201008071216.16554-1-olaf@aepfle.de Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-16hv_balloon: try to merge system ram resourcesDavid Hildenbrand1-1/+1
Let's try to merge system ram resources we add, to minimize the number of resources in /proc/iomem. We don't care about the boundaries of individual chunks we added. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Liu <wei.liu@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Grall <julien@xen.org> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <lenb@kernel.org> Cc: Leonardo Bras <leobras.c@gmail.com> Cc: Libor Pechacek <lpechacek@suse.cz> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Link: https://lkml.kernel.org/r/20200911103459.10306-9-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/memory_hotplug: prepare passing flags to add_memory() and friendsDavid Hildenbrand1-1/+1
We soon want to pass flags, e.g., to mark added System RAM resources. mergeable. Prepare for that. This patch is based on a similar patch by Oscar Salvador: https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@suse.de Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Juergen Gross <jgross@suse.com> # Xen related part Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Wei Liu <wei.liu@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Libor Pechacek <lpechacek@suse.cz> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Leonardo Bras <leobras.c@gmail.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Julien Grall <julien@xen.org> Cc: Kees Cook <keescook@chromium.org> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richardw.yang@linux.intel.com> Link: https://lkml.kernel.org/r/20200911103459.10306-5-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07hv_balloon: don't check for memhp_auto_online manuallyDavid Hildenbrand1-15/+10
We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-26hv_balloon: Balloon up according to request page numberTianyu Lan1-10/+3
Current code has assumption that balloon request memory size aligns with 2MB. But actually Hyper-V doesn't guarantee such alignment. When balloon driver receives non-aligned balloon request, it produces warning and balloon up more memory than requested in order to keep 2MB alignment. Remove the warning and balloon up memory according to actual requested memory size. Fixes: f6712238471a ("hv: hv_balloon: avoid memory leak on alloc_error of 2MB memory block") Cc: stable@vger.kernel.org Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-3/+1
Merge updates from Andrew Morton: "Incoming: - a small number of updates to scripts/, ocfs2 and fs/buffer.c - most of MM I still have quite a lot of material (mostly not MM) staged after linux-next due to -next dependencies. I'll send those across next week as the preprequisites get merged up" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits) mm/page_io.c: annotate refault stalls from swap_readpage mm/Kconfig: fix trivial help text punctuation mm/Kconfig: fix indentation mm/memory_hotplug.c: remove __online_page_set_limits() mm: fix typos in comments when calling __SetPageUptodate() mm: fix struct member name in function comments mm/shmem.c: cast the type of unmap_start to u64 mm: shmem: use proper gfp flags for shmem_writepage() mm/shmem.c: make array 'values' static const, makes object smaller userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register() userfaultfd: wrap the common dst_vma check into an inlined function userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb() userfaultfd: use vma_pagesize for all huge page size calculation mm/madvise.c: use PAGE_ALIGN[ED] for range checking mm/madvise.c: replace with page_size() in madvise_inject_error() mm/mmap.c: make vma_merge() comment more easy to understand mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops autonuma: reduce cache footprint when scanning page tables autonuma: fix watermark checking in migrate_balanced_pgdat() ...
2019-12-01mm/memory_hotplug.c: remove __online_page_set_limits()Souptick Joarder1-1/+0
__online_page_set_limits() is a dummy function - remove it and all callers. Link: http://lkml.kernel.org/r/8e1bc9d3b492f6bde16e95ebc1dee11d6aefabd7.1567889743.git.jrdr.linux@gmail.com Link: http://lkml.kernel.org/r/854db2cf8145d9635249c95584d9a91fd774a229.1567889743.git.jrdr.linux@gmail.com Link: http://lkml.kernel.org/r/9afe6c5a18158f3884a6b302ac2c772f3da49ccc.1567889743.git.jrdr.linux@gmail.com Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01hv_balloon: use generic_online_page()David Hildenbrand1-2/+1
Let's use the generic onlining function - which will now also take care of calling kernel_map_pages(). Link: http://lkml.kernel.org/r/20190909114830.662-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Qian Cai <cai@lca.pw> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-22hv_balloon: Add the support of hibernationDexuan Cui1-2/+85
When hibernation is enabled, we must ignore the balloon up/down and hot-add requests from the host, if any. Signed-off-by: Dexuan Cui <decui@microsoft.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-22Drivers: hv: balloon: Remove dependencies on guest page sizeHimadri Pandya1-13/+12
Hyper-V assumes page size to be 4K. This might not be the case for ARM64 architecture. Hence use hyper-v specific page size and page shift definitions to avoid conflicts between different host and guest page sizes on ARM64. Also, remove some old and incorrect comments and redefine ballooning granularities to handle larger page sizes correctly. Signed-off-by: Himadri Pandya <himadri18.07@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31hv_balloon: Reorganize the probe functionDexuan Cui1-58/+66
Move the code that negotiates with the host to a new function balloon_connect_vsp() and improve the error handling. This makes the code more readable and paves the way for the support of hibernation in future. Makes no real logic change here. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31hv_balloon: Use a static page for the balloon_up send bufferDexuan Cui1-15/+4
It's unnecessary to dynamically allocate the buffer. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 280Thomas Gleixner1-11/+1
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 version 2 as published by the free software foundation 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 good title or non infringement see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141900.459653302@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-06hv_balloon: mark inflated pages PG_offlineDavid Hildenbrand1-2/+12
Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06mm/page_alloc.c: memory hotplug: free pages as higher orderArun KS1-3/+4
When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-09hv_balloon: avoid touching uninitialized struct page during tail onliningVitaly Kuznetsov1-4/+6
Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-28mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS1-1/+1
totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm: reference totalram_pages and managed_pages once per functionArun KS1-9/+10
Patch series "mm: convert totalram_pages, totalhigh_pages and managed pages to atomic", v5. This series converts totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. This patch (of 4): This is in preparation to a later patch which converts totalram_pages and zone->managed_pages to atomic variables. Please note that re-reading the value might lead to a different value and as such it could lead to unexpected behavior. There are no known bugs as a result of the current code but it is better to prevent from them in principle. Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-15hv_balloon: Replace spin_is_locked() with lockdepLance Roy1-1/+1
lockdep_assert_held() is better suited to checking locking requirements, since it won't get confused when someone else holds the lock. This is also a step towards possibly removing spin_is_locked(). Signed-off-by: Lance Roy <ldr709@gmail.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03use the new async probing feature for the hyperv driversArjan van de Ven1-0/+3
Recent kernels support asynchronous probing; most hyperv drivers can be probed async easily so set the required flag for this. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-06hv_balloon: trace post_statusVitaly Kuznetsov1-0/+6
Hyper-V balloon driver makes non-trivial calculations to convert Linux's representation of free/used memory to what Hyper-V host expects to see. Add a tracepoint to see what's being sent and where the data comes from. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-06hv_balloon: fix bugs in num_pages_onlined accountingVitaly Kuznetsov1-13/+69
Our num_pages_onlined accounting is buggy: 1) In case we're offlining a memory block which was present at boot (e.g. when there was no hotplug at all) we subtract 32k from 0 and as num_pages_onlined is unsigned get a very big positive number. 2) Commit 6df8d9aaf3af ("Drivers: hv: balloon: Correctly update onlined page count") made num_pages_onlined counter accurate on onlining but totally incorrect on offlining for partly populated regions: no matter how many pages were onlined and what was actually added to num_pages_onlined counter we always subtract the full region (32k) so again, num_pages_onlined can wrap around zero. By onlining/offlining the same partly populated region multiple times we can make the situation worse. Solve these issues by doing accurate accounting on offlining: walk HAS list, check for covered range and gaps. Fixes: 6df8d9aaf3af ("Drivers: hv: balloon: Correctly update onlined page count") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-06hv_balloon: simplify hv_online_page()/hv_page_online_one()Vitaly Kuznetsov1-22/+5
Instead of doing pfn_to_page() and continuosly casting page to unsigned long just cache the pfn of the page with page_to_pfn(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-06hv_balloon: fix printk loglevelVitaly Kuznetsov1-6/+6
We have a mix of different ideas of which loglevel should be used. Unify on the following: - pr_info() for normal operation - pr_warn() for 'strange' host behavior - pr_err() for all errors. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16Drivers: hv: balloon: Initialize last_post_time on startupAlex Ng1-0/+1
When left uninitialized, this sometimes fails the following check in post_status(): if (!time_after(now, (last_post_time + HZ))) { return; } This causes unnecessary delays in reporting memory pressure to host after booting up. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16Drivers: hv: balloon: Show the max dynamic memory assignedAlex Ng1-2/+2
Previously we were only showing max number of pages. We should make it more clear that this value is the max amount of dynamic memory that the Hyper-V host is willing to assign to this guest. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16Drivers: hv: balloon: Correctly update onlined page countAlex Ng1-4/+3
Previously, num_pages_onlined was updated using value from memory online notifier. This is incorrect because they assume that all hot-added pages are online, even though we only online the amount that's backed by the host. We should update num_pages_onlined only when the balloon driver marks a page as online. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17vmbus: remove useless return'sStephen Hemminger1-2/+0
No need for empty return at end of void function Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-31Drivers: hv: balloon: add a fall through comment to hv_memory_notifier()Vitaly Kuznetsov1-0/+1
Coverity scan gives a warning when there is fall through in a switch without a comment. This fall through is intentional as ol_waitevent needs to be completed to unblock hv_mem_hot_add() allowing it to process next requests regardless of the result of if we were able to online this block. Reported-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07Drivers: hv: balloon: Fix info request to show max page countAlex Ng1-2/+7
Balloon driver was only printing the size of the info blob and not the actual content. This fixes it so that the info blob (max page count as configured in Hyper-V) is printed out. Signed-off-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07Drivers: hv: balloon: Add logging for dynamic memory operationsAlex Ng1-3/+28
Added logging to help troubleshoot common ballooning, hot add, and versioning issues. Signed-off-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07Drivers: hv: balloon: Disable hot add when CONFIG_MEMORY_HOTPLUG is not setAlex Ng1-0/+4
If the guest does not support memory hotplugging, it should respond to the host with zero pages added and successful result code. This signals to the host that hotplugging is not supported and the host will avoid sending future hot-add requests. Signed-off-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: balloon: Use available memory value in pressure reportAlex Ng1-8/+5
Reports for available memory should use the si_mem_available() value. The previous freeram value does not include available page cache memory. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: balloon: replace ha_region_mutex with spinlockVitaly Kuznetsov1-45/+53
lockdep reports possible circular locking dependency when udev is used for memory onlining: systemd-udevd/3996 is trying to acquire lock: ((memory_chain).rwsem){++++.+}, at: [<ffffffff810d137e>] __blocking_notifier_call_chain+0x4e/0xc0 but task is already holding lock: (&dm_device.ha_region_mutex){+.+.+.}, at: [<ffffffffa015382e>] hv_memory_notifier+0x5e/0xc0 [hv_balloon] ... which is probably a false positive because we take and release ha_region_mutex from memory notifier chain depending on the arg. No real deadlocks were reported so far (though I'm not really sure about preemptible kernels...) but we don't really need to hold the mutex for so long. We use it to protect ha_region_list (and its members) and the num_pages_onlined counter. None of these operations require us to sleep and nothing is slow, switch to using spinlock with interrupts disabled. While on it, replace list_for_each -> list_for_each_entry as we actually need entries in all these cases, drop meaningless list_empty() checks. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: balloon: don't wait for ol_waitevent when memhp_auto_online is ↵Vitaly Kuznetsov1-6/+9
enabled With the recently introduced in-kernel memory onlining (MEMORY_HOTPLUG_DEFAULT_ONLINE) these is no point in waiting for pages to come online in the driver and we can get rid of the waiting. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: balloon: account for gaps in hot add regionsVitaly Kuznetsov1-37/+94
I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: balloon: keep track of where ha_region startsVitaly Kuznetsov1-2/+5
Windows 2012 (non-R2) does not specify hot add region in hot add requests and the logic in hot_add_req() is trying to find a 128Mb-aligned region covering the request. It may also happen that host's requests are not 128Mb aligned and the created ha_region will start before the first specified PFN. We can't online these non-present pages but we don't remember the real start of the region. This is a regression introduced by the commit 5abbbb75d733 ("Drivers: hv: hv_balloon: don't lose memory when onlining order is not natural"). While the idea of keeping the 'moving window' was wrong (as there is no guarantee that hot add requests come ordered) we should still keep track of covered_start_pfn. This is not a revert, the logic is different. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01Drivers: hv: balloon: reset host_specified_ha_regionVitaly Kuznetsov1-0/+1
We set host_specified_ha_region = true on certain request but this is a global state which stays 'true' forever. We need to reset it when we receive a request where ha_region is not specified. I did not see any real issues, the bug was found by code inspection. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01Drivers: hv: balloon: don't crash when memory is added in non-sorted orderVitaly Kuznetsov1-2/+2
When we iterate through all HA regions in handle_pg_range() we have an assumption that all these regions are sorted in the list and the 'start_pfn >= has->end_pfn' check is enough to find the proper region. Unfortunately it's not the case with WS2016 where host can hot-add regions in a different order. We end up modifying the wrong HA region and crashing later on pages online. Modify the check to make sure we found the region we were searching for while iterating. Fix the same check in pfn_covered() as well. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05Drivers: hv: balloon: Enable dynamic memory protocol negotiation with ↵Alex Ng1-6/+20
Windows 10 hosts Support Win10 protocol for Dynamic Memory. Thia patch allows guests on Win10 hosts to hot-add memory even when dynamic memory is not enabled on the guest. Signed-off-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-05 01:33:51 +0300