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We currently initialize the memmap such that PG_reserved is set and the
refcount of the page is 1. In virtio-mem code, we have to manually clear
that PG_reserved flag to make memory offlining with partially hotplugged
memory blocks possible: has_unmovable_pages() would otherwise bail out on
such pages.
We want to avoid PG_reserved where possible and move to typed pages
instead. Further, we want to further enlighten memory offlining code
about PG_offline: offline pages in an online memory section. One example
is handling managed page count adjustments in a cleaner way during memory
offlining.
So let's initialize the pages with PG_offline instead of PG_reserved.
generic_online_page()->__free_pages_core() will now clear that flag before
handing that memory to the buddy.
Note that the page refcount is still 1 and would forbid offlining of such
memory except when special care is take during GOING_OFFLINE as currently
only implemented by virtio-mem.
With this change, we can now get non-PageReserved() pages in the XEN
balloon list. From what I can tell, that can already happen via
decrease_reservation(), so that should be fine.
HV-balloon should not really observe a change: partial online memory
blocks still cannot get surprise-offlined, because the refcount of these
PageOffline() pages is 1.
Update virtio-mem, HV-balloon and XEN-balloon code to be aware that
hotplugged pages are now PageOffline() instead of PageReserved() before
they are handed over to the buddy.
We'll leave the ZONE_DEVICE case alone for now.
Note that self-hosted vmemmap pages will no longer be marked as
reserved. This matches ordinary vmemmap pages allocated from the buddy
during memory hotplug. Now, really only vmemmap pages allocated from
memblock during early boot will be marked reserved. Existing
PageReserved() checks seem to be handling all relevant cases correctly
even after this change.
Link: https://lkml.kernel.org/r/20240607090939.89524-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de> [generic memory-hotplug bits]
Cc: Alexander Potapenko <glider@google.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Marco Elver <elver@google.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix issues reported by checkpatch.pl script in hv.c and
balloon.c
- Remove unnecessary parentheses
- Remove extra newlines
- Remove extra spaces
- Add spaces between comparison operators
- Remove comparison with NULL in if statements
No functional changes intended
Signed-off-by: Aditya Nagesh <adityanagesh@linux.microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1717152521-6439-1-git-send-email-adityanagesh@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1717152521-6439-1-git-send-email-adityanagesh@linux.microsoft.com>
The Hyper-V balloon driver supports hot-add of memory in addition
to ballooning. Current code hot-adds in fixed size chunks of
128 MiB (fixed constant HA_CHUNK in the code). While this works
in Hyper-V VMs with 64 GiB or less or memory where the Linux
memblock size is 128 MiB, the hot-add fails for larger memblock
sizes because add_memory() expects memory to be added in chunks
that match the memblock size. Messages like the following are
reported when Linux has a 256 MiB memblock size:
[ 312.668859] Block size [0x10000000] unaligned hotplug range:
start 0x310000000, size 0x8000000
[ 312.668880] hv_balloon: hot_add memory failed error is -22
[ 312.668984] hv_balloon: Memory hot add failed
Larger memblock sizes are usually used in VMs with more than
64 GiB of memory, depending on the alignment of the VM's
physical address space.
Fix this problem by having the Hyper-V balloon driver determine
the Linux memblock size, and process hot-add requests in that
chunk size instead of a fixed 128 MiB. Also update the hot-add
alignment requested of the Hyper-V host to match the memblock
size.
The code changes look significant, but in fact are just a
simple text substitution of a new global variable for the
previous HA_CHUNK constant. No algorithms are changed except
to initialize the new global variable and to calculate the
alignment value to pass to Hyper-V. Testing with memblock
sizes of 256 MiB and 2 GiB shows correct operation.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240503154312.142466-2-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240503154312.142466-2-mhklinux@outlook.com>
Code sequences equivalent to ALIGN(), ALIGN_DOWN(), and umin() are
currently open coded. Change these to use the kernel macro to
improve code clarity. ALIGN() and ALIGN_DOWN() require the
alignment value to be a power of 2, which is the case here.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240503154312.142466-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240503154312.142466-1-mhklinux@outlook.com>
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Merge tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- Support for SEV-SNP guests on Hyper-V (Tianyu Lan)
- Support for TDX guests on Hyper-V (Dexuan Cui)
- Use SBRM API in Hyper-V balloon driver (Mitchell Levy)
- Avoid dereferencing ACPI root object handle in VMBus driver (Maciej
Szmigiero)
- A few misecllaneous fixes (Jiapeng Chong, Nathan Chancellor, Saurabh
Sengar)
* tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits)
x86/hyperv: Remove duplicate include
x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's
x86/hyperv: Remove hv_isolation_type_en_snp
x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor
Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor
x86/hyperv: Introduce a global variable hyperv_paravisor_present
Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM
x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests
Drivers: hv: vmbus: Support fully enlightened TDX guests
x86/hyperv: Support hypercalls for fully enlightened TDX guests
x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests
x86/hyperv: Fix undefined reference to isolation_type_en_snp without CONFIG_HYPERV
x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stub
hv: hyperv.h: Replace one-element array with flexible-array member
Drivers: hv: vmbus: Don't dereference ACPI root object handle
x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES
x86/hyperv: Add smp support for SEV-SNP guest
clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest
x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest
drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest
...
This patch is intended as a proof-of-concept for the new SBRM
machinery[1]. For some brief background, the idea behind SBRM is using
the __cleanup__ attribute to automatically unlock locks (or otherwise
release resources) when they go out of scope, similar to C++ style RAII.
This promises some benefits such as making code simpler (particularly
where you have lots of goto fail; type constructs) as well as reducing
the surface area for certain kinds of bugs.
The changes in this patch should not result in any difference in how the
code actually runs (i.e., it's purely an exercise in this new syntax
sugar). In one instance SBRM was not appropriate, so I left that part
alone, but all other locking/unlocking is handled automatically in this
patch.
[1] https://lore.kernel.org/all/20230626125726.GU4253@hirez.programming.kicks-ass.net/
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: "Mitchell Levy (Microsoft)" <levymitchell0@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230807-sbrm-hyperv-v2-1-9d2ac15305bd@gmail.com
Several places in code for Hyper-V reference the
per-CPU variable hyperv_pcpu_input_arg. Older code uses a multi-line
sequence to reference the variable, and usually includes a cast.
Newer code does a much simpler direct assignment. The latter is
preferable as the complexity of the older code is unnecessary.
Update older code to use the simpler direct assignment.
Signed-off-by: Nischala Yelchuri <niyelchu@linux.microsoft.com>
Link: https://lore.kernel.org/r/1687286438-9421-1-git-send-email-niyelchu@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Merge tag 'hyperv-next-signed-20230220' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- allow Linux to run as the nested root partition for Microsoft
Hypervisor (Jinank Jain and Nuno Das Neves)
- clean up the return type of callback functions (Dawei Li)
* tag 'hyperv-next-signed-20230220' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
x86/hyperv: Fix hv_get/set_register for nested bringup
Drivers: hv: Make remove callback of hyperv driver void returned
Drivers: hv: Enable vmbus driver for nested root partition
x86/hyperv: Add an interface to do nested hypercalls
Drivers: hv: Setup synic registers in case of nested root partition
x86/hyperv: Add support for detecting nested hypervisor
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Fixes: d180e0a1be ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")
Cc: stable <stable@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230202140918.2289522-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit fc7a6209d5 ("bus: Make remove callback return
void") forces bus_type::remove be void-returned, it doesn't
make much sense for any bus based driver implementing remove
callbalk to return non-void to its caller.
As such, change the remove function for Hyper-V VMBus based
drivers to return void.
Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Link: https://lore.kernel.org/r/TYCP286MB2323A93C55526E4DF239D3ACCAFA9@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Newer versions of Hyper-V allow reporting unused guest pages in chunks
smaller than 2 Mbytes. Using smaller chunks allows reporting more
unused guest pages, but with increased overhead in the finding the
small chunks. To make this tradeoff configurable, use the existing
page_reporting_order module parameter to control the reporting order.
Drop and refine checks that restricted the minimun page reporting order
to 2Mbytes size pages. Add appropriate checks to make sure the
underlying Hyper-V versions support cold discard hints of any order
(and not just starting from 9)
Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1664517699-1085-3-git-send-email-shradhagupta@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Allow the guest to know how much it is ballooned by the host.
It is useful when debugging out of memory conditions.
When host gets back memory from the guest it is accounted
as used memory in the guest but the guest have no way to know
how much it is actually ballooned.
Expose current state, flags and max possible memory to the guest.
While at it - fix a 10+ years old typo.
Signed-off-by: Alexander Atanasov <alexander.atanasov@virtuozzo.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220711181825.52318-1-alexander.atanasov@virtuozzo.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Add missing cleanup in balloon_probe() if the call to
balloon_connect_vsp() fails. Also correctly handle cleanup in
balloon_remove() when dm_state is DM_INIT_ERROR because
balloon_resume() failed.
Signed-off-by: Shradha Gupta <shradhagupta@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220516045058.GA7933@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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>
DM_STATUS_REPORT expects the numbers of pages in the unit of 4k pages
(HV_HYP_PAGE) instead of guest pages, so to make it work when guest page
sizes are larger than 4k, convert the numbers of guest pages into the
numbers of HV_HYP_PAGEs.
Note that the numbers of guest pages are still used for tracing because
tracing is internal to the guest kernel.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220325023212.1570049-2-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 96d9d1fa5c
("Drivers: hv: balloon: account for vmbus packet header in
max_pkt_size").
Fixes: 9aa8b50b2b ("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>
Commit adae1e931a ("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: adae1e931a ("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>
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>
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>
Linux has support for free page reporting now (36e66c554b) 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>
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>
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>
'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>
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: b3bb97b8a4 ("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>
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>
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>
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>
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: f671223847 ("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>
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()
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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 6df8d9aaf3 ("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: 6df8d9aaf3 ("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>
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>
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>
