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2021-09-08virtio-mem: use a single dynamic memory group for a single virtio-mem deviceDavid Hildenbrand1-3/+19
Let's use a single dynamic memory group. Link: https://lkml.kernel.org/r/20210806124715.17090-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hui Zhu <teawater@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: Marek Kedzierski <mkedzier@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> 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>
2021-09-08mm/memory_hotplug: remove nid parameter from remove_memory() and friendsDavid Hildenbrand1-2/+2
There is only a single user remaining. We can simply lookup the nid only used for node offlining purposes when walking our memory blocks. We don't expect to remove multi-nid ranges; and if we'd ever do, we most probably don't care about removing multi-nid ranges that actually result in empty nodes. If ever required, we can detect the "multi-nid" scenario and simply try offlining all online nodes. Link: https://lkml.kernel.org/r/20210712124052.26491-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) 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: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joe Perches <joe@perches.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michel Lespinasse <michel@lespinasse.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta@ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pierre Morel <pmorel@linux.ibm.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Rich Felker <dalias@libc.org> Cc: Sergei Trofimovich <slyfox@gentoo.org> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-27virtio-mem: fix sleeping in RCU read side section in virtio_mem_online_page_cb()David Hildenbrand1-1/+8
virtio_mem_set_fake_offline() might sleep now, and we call it under rcu_read_lock(). To fix it, simply move the rcu_read_unlock() further up, as we're done with the device. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 6cc26d77613a: "virtio-mem: use page_offline_(start|end) when setting PageOffline() Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: virtualization@lists.linux-foundation.org Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-09Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-164/+174
Pull virtio,vhost,vdpa updates from Michael Tsirkin: - Doorbell remapping for ifcvf, mlx5 - virtio_vdpa support for mlx5 - Validate device input in several drivers (for SEV and friends) - ZONE_MOVABLE aware handling in virtio-mem - Misc fixes, cleanups * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits) virtio-mem: prioritize unplug from ZONE_MOVABLE in Big Block Mode virtio-mem: simplify high-level unplug handling in Big Block Mode virtio-mem: prioritize unplug from ZONE_MOVABLE in Sub Block Mode virtio-mem: simplify high-level unplug handling in Sub Block Mode virtio-mem: simplify high-level plug handling in Sub Block Mode virtio-mem: use page_zonenum() in virtio_mem_fake_offline() virtio-mem: don't read big block size in Sub Block Mode virtio/vdpa: clear the virtqueue state during probe vp_vdpa: allow set vq state to initial state after reset virtio-pci library: introduce vp_modern_get_driver_features() vdpa: support packed virtqueue for set/get_vq_state() virtio-ring: store DMA metadata in desc_extra for split virtqueue virtio: use err label in __vring_new_virtqueue() virtio_ring: introduce virtqueue_desc_add_split() virtio_ring: secure handling of mapping errors virtio-ring: factor out desc_extra allocation virtio_ring: rename vring_desc_extra_packed virtio-ring: maintain next in extra state for packed virtqueue vdpa/mlx5: Clear vq ready indication upon device reset vdpa/mlx5: Add support for doorbell bypassing ...
2021-07-08virtio-mem: prioritize unplug from ZONE_MOVABLE in Big Block ModeDavid Hildenbrand1-1/+26
Let's handle unplug in Big Block Mode similar to Sub Block Mode -- prioritize memory blocks onlined to ZONE_MOVABLE. We won't care further about big blocks with mixed zones, as it's rather a corner case that won't matter in practice. Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-8-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: simplify high-level unplug handling in Big Block ModeDavid Hildenbrand1-72/+24
Let's simplify high-level big block selection when unplugging in Big Block Mode. Combine handling of offline and online blocks. We can get rid of virtio_mem_bbm_bb_is_offline() and simply use virtio_mem_bbm_offline_remove_and_unplug_bb(), as that already tolerates offline parts. We can race with concurrent onlining/offlining either way, so we don;t have to be super correct by failing if an offline big block we'd like to unplug just got (partially) onlined. Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-7-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: prioritize unplug from ZONE_MOVABLE in Sub Block ModeDavid Hildenbrand1-20/+52
Until now, memory provided by a single virtio-mem device was usually either onlined completely to ZONE_MOVABLE (online_movable) or to ZONE_NORMAL (online_kernel); however, that will change in the future. There are two reasons why we want to track to which zone a memory blocks belongs to and prioritize ZONE_MOVABLE blocks: 1) Memory managed by ZONE_MOVABLE can more likely get unplugged, therefore, resulting in a faster memory hotunplug process. Further, we can more reliably unplug and remove complete memory blocks, removing metadata allocated for the whole memory block. 2) We want to avoid corner cases where unplugging with the current scheme (highest to lowest address) could result in accidential zone imbalances, whereby we remove too much ZONE_NORMAL memory for ZONE_MOVABLE memory of the same device. Let's track the zone via memory block states and try unplug from ZONE_MOVABLE first. Rename VIRTIO_MEM_SBM_MB_ONLINE* to VIRTIO_MEM_SBM_MB_KERNEL* to avoid even longer state names. In commit 27f852795a06 ("virtio-mem: don't special-case ZONE_MOVABLE"), we removed slightly similar tracking for fully plugged memory blocks to support unplugging from ZONE_MOVABLE at all -- as we didn't allow partially plugged memory blocks in ZONE_MOVABLE before that. That commit already mentioned "In the future, we might want to remember the zone again and use the information when (un)plugging memory." Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-6-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: simplify high-level unplug handling in Sub Block ModeDavid Hildenbrand1-46/+57
Let's simplify by introducing a new virtio_mem_sbm_unplug_any_sb(), similar to virtio_mem_sbm_plug_any_sb(), to simplify high-level memory block selection when unplugging in Sub Block Mode. Rename existing virtio_mem_sbm_unplug_any_sb() to virtio_mem_sbm_unplug_any_sb_raw(). The only change is that we now temporarily unlock the hotplug mutex around cond_resched() when processing offline memory blocks, which doesn't make a real difference as we already have to temporarily unlock in virtio_mem_sbm_unplug_any_sb_offline() when removing a memory block. Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-5-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: simplify high-level plug handling in Sub Block ModeDavid Hildenbrand1-28/+17
Let's simplify high-level memory block selection when plugging in Sub Block Mode. No need for two separate loops when selecting memory blocks for plugging memory. Avoid passing the "online" state by simply obtaining the state in virtio_mem_sbm_plug_any_sb(). Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-4-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: use page_zonenum() in virtio_mem_fake_offline()David Hildenbrand1-1/+1
Let's use page_zonenum() instead of zone_idx(page_zone()). Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-3-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-mem: don't read big block size in Sub Block ModeDavid Hildenbrand1-7/+8
We are reading a Big Block Mode value while in Sub Block Mode when initializing. Fortunately, vm->bbm.bb_size maps to some counter in the vm->sbm.mb_count array, which is 0 at that point in time. No harm done; still, this was unintended and is not future-proof. Fixes: 4ba50cd3355d ("virtio-mem: Big Block Mode (BBM) memory hotplug") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210602185720.31821-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-06-30virtio-mem: use page_offline_(start|end) when setting PageOffline()David Hildenbrand1-0/+2
Let's properly use page_offline_(start|end) to synchronize setting PageOffline(), so we won't have valid page access to unplugged memory regions from /proc/kcore. Existing balloon implementations usually allow reading inflated memory; doing so might result in unnecessary overhead in the hypervisor, which is currently the case with virtio-mem. For future virtio-mem use cases, it will be different when using shmem, huge pages, !anonymous private mappings, ... as backing storage for a VM. virtio-mem unplugged memory must no longer be accessed and access might result in undefined behavior. There will be a virtio spec extension to document this change, including a new feature flag indicating the changed behavior. We really don't want to race against PFN walkers reading random page content. Link: https://lkml.kernel.org/r/20210526093041.8800-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Aili Yao <yaoaili@kingsoft.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jiri Bohac <jbohac@suse.cz> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Roman Gushchin <guro@fb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Steven Price <steven.price@arm.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-15/+28
Merge more updates from Andrew Morton: "118 patches: - The rest of MM. Includes kfence - another runtime memory validator. Not as thorough as KASAN, but it has unmeasurable overhead and is intended to be usable in production builds. - Everything else Subsystems affected by this patch series: alpha, procfs, sysctl, misc, core-kernel, MAINTAINERS, lib, bitops, checkpatch, init, coredump, seq_file, gdb, ubsan, initramfs, and mm (thp, cma, vmstat, memory-hotplug, mlock, rmap, zswap, zsmalloc, cleanups, kfence, kasan2, and pagemap2)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits) MIPS: make userspace mapping young by default initramfs: panic with memory information ubsan: remove overflow checks kgdb: fix to kill breakpoints on initmem after boot scripts/gdb: fix list_for_each x86: fix seq_file iteration for pat/memtype.c seq_file: document how per-entry resources are managed. fs/coredump: use kmap_local_page() init/Kconfig: fix a typo in CC_VERSION_TEXT help text init: clean up early_param_on_off() macro init/version.c: remove Version_<LINUX_VERSION_CODE> symbol checkpatch: do not apply "initialise globals to 0" check to BPF progs checkpatch: don't warn about colon termination in linker scripts checkpatch: add kmalloc_array_node to unnecessary OOM message check checkpatch: add warning for avoiding .L prefix symbols in assembly files checkpatch: improve TYPECAST_INT_CONSTANT test message checkpatch: prefer ftrace over function entry/exit printks checkpatch: trivial style fixes checkpatch: ignore warning designated initializers using NR_CPUS checkpatch: improve blank line after declaration test ...
2021-02-26virtio-mem: check against mhp_get_pluggable_range() which memory we can hotplugDavid Hildenbrand1-14/+27
Right now, we only check against MAX_PHYSMEM_BITS - but turns out there are more restrictions of which memory we can actually hotplug, especially om arm64 or s390x once we support them: we might receive something like -E2BIG or -ERANGE from add_memory_driver_managed(), stopping device operation. So, check right when initializing the device which memory we can add, warning the user. Try only adding actually pluggable ranges: in the worst case, no memory provided by our device is pluggable. In the usual case, we expect all device memory to be pluggable, and in corner cases only some memory at the end of the device-managed memory region to not be pluggable. Link: https://lkml.kernel.org/r/1612149902-7867-5-git-send-email-anshuman.khandual@arm.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>
2021-02-23virtio-mem: Assign boolean values to a bool variableJiapeng Zhong1-1/+1
Fix the following coccicheck warnings: ./drivers/virtio/virtio_mem.c:2580:2-25: WARNING: Assignment of 0/1 to bool variable. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com> Link: https://lore.kernel.org/r/1611129031-82818-1-git-send-email-abaci-bugfix@linux.alibaba.com Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: Big Block Mode (BBM) - safe memory hotunplugDavid Hildenbrand1-2/+95
Let's add a safe mechanism to unplug memory, avoiding long/endless loops when trying to offline memory - similar to in SBM. Fake-offline all memory (via alloc_contig_range()) before trying to offline+remove it. Use this mode as default, but allow to enable the other mode explicitly (which could give better memory hotunplug guarantees in some environments). The "unsafe" mode can be enabled e.g., via virtio_mem.bbm_safe_unplug=0 on the cmdline. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-30-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: Big Block Mode (BBM) - basic memory hotunplugDavid Hildenbrand1-1/+155
Let's try to unplug completely offline big blocks first. Then, (if enabled via unplug_offline) try to offline and remove whole big blocks. No locking necessary - we can deal with concurrent onlining/offlining just fine. Note1: This is sub-optimal and might be dangerous in some environments: we could end up in an infinite loop when offlining (e.g., long-term pinnings), similar as with DIMMs. We'll introduce safe memory hotunplug via fake-offlining next, and use this basic mode only when explicitly enabled. Note2: Without ZONE_MOVABLE, memory unplug will be extremely unreliable with bigger block sizes. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-29-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: allow to force Big Block Mode (BBM) and set the big block sizeDavid Hildenbrand1-3/+28
Let's allow to force BBM, even if subblocks would be possible. Take care of properly calculating the first big block id, because the start address might no longer be aligned to the big block size. Also, allow to manually configure the size of Big Blocks. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-27-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: Big Block Mode (BBM) memory hotplugDavid Hildenbrand1-119/+441
Currently, we do not support device block sizes that exceed the Linux memory block size. For example, having a device block size of 1 GiB (e.g., gigantic pages in the hypervisor) won't work with 128 MiB Linux memory blocks. Let's implement Big Block Mode (BBM), whereby we add/remove at least one Linux memory block at a time. With a 1 GiB device block size, a Big Block (BB) will cover 8 Linux memory blocks. We'll keep registering the online_page_callback machinery, it will be used for safe memory hotunplug in BBM next. Note: BBM is properly prepared for variable-sized Linux memory blocks that we might see in the future. So we won't care how many Linux memory blocks a big block actually spans, and how the memory notifier is called. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-26-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: factor out adding/removing memory from LinuxDavid Hildenbrand1-34/+73
Let's use wrappers for the low-level functions that dev_dbg/dev_warn and work on addr + size, such that we can reuse them for adding/removing in other granularity. We only warn when adding memory failed, because that's something to pay attention to. We won't warn when removing failed, we'll reuse that in racy context soon (and we do have proper BUG_ON() statements in the current cases where it must never happen). Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-25-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: memory notifier callbacks are specific to Sub Block Mode (SBM)David Hildenbrand1-14/+15
Let's rename accordingly. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-24-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virito-mem: existing (un)plug functions are specific to Sub Block Mode (SBM)David Hildenbrand1-47/+43
Let's rename them accordingly. virtio_mem_plug_request() and virtio_mem_unplug_request() will be handled separately. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-23-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: memory block ids are specific to Sub Block Mode (SBM)David Hildenbrand1-23/+23
Let's move first_mb_id/next_mb_id/last_usable_mb_id accordingly. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-22-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: nb_sb_per_mb and subblock_size are specific to Sub Block Mode (SBM)David Hildenbrand1-48/+48
Let's rename to "sbs_per_mb" and "sb_size" and move accordingly. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-21-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virito-mem: subblock states are specific to Sub Block Mode (SBM)David Hildenbrand1-63/+69
Let's rename and move accordingly. While at it, rename sb_bitmap to "sb_states". Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-20-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: memory block states are specific to Sub Block Mode (SBM)David Hildenbrand1-106/+109
let's use a new "sbm" sub-struct to hold SBM-specific state and rename + move applicable definitions, functions, and variables (related to memory block states). While at it: - Drop the "_STATE" part from memory block states - Rename "nb_mb_state" to "mb_count" - "set_mb_state" / "get_mb_state" vs. "mb_set_state" / "mb_get_state" - Don't use lengthy "enum virtio_mem_smb_mb_state", simply use "uint8_t" Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-19-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virito-mem: document Sub Block Mode (SBM)David Hildenbrand1-0/+15
Let's add some documentation for the current mode - Sub Block Mode (SBM) - to prepare for a new mode - Big Block Mode (BBM). Follow-up patches will properly factor out the existing Sub Block Mode (SBM) and implement Big Block Mode (BBM). Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-18-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: generalize handling when memory is getting onlined deferredDavid Hildenbrand1-32/+63
We don't want to add too much memory when it's not getting onlined immediately, to avoid running OOM. Generalize the handling, to avoid making use of memory block states. Use a threshold of 1 GiB for now. Properly adjust the offline size when adding/removing memory. As we are not always protected by a lock when touching the offline size, use an atomic64_t. We don't care about races (e.g., someone offlining memory while we are adding more), only about consistent values. (1 GiB needs a memmap of ~16MiB - which sounds reasonable even for setups with little boot memory and (possibly) one virtio-mem device per node) We don't want to retrigger when onlining is caused immediately by our action (e.g., adding memory which immediately gets onlined), so use a flag to indicate if the workqueue is active and use that as an indicator whether to trigger a retry. This will also be especially relevant for Big Block Mode (BBM), whereby we might re-online memory in case offlining of another memory block failed. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-17-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: don't always trigger the workqueue when offlining memoryDavid Hildenbrand1-12/+28
Let's trigger from offlining code only when we're not allowed to unplug online memory. Handle the other case (memmap possibly freeing up another memory block) when actually removing memory. We now also properly handle the case when removing already offline memory blocks via virtio_mem_mb_remove(). When removing via virtio_mem_remove(), when unloading the driver, virtio_mem_retry() is a NOP and safe to use. While at it, move retry handling when offlining out of virtio_mem_notify_offline(), to share it with Big Block Mode (BBM) soon. This is a preparation for Big Block Mode (BBM), whereby we can see some temporary offlining of memory blocks without actually making progress. Imagine you have a Big Block that spans to Linux memory blocks. Assume the first Linux memory blocks has no unmovable data on it. When we would call offline_and_remove_memory() on the big block, we would 1. Try to offline the first block. Works, notifiers triggered. virtio_mem_retry() called. 2. Try to offline the second block. Does not work. 3. Re-online first block. 4. Exit to main loop, exit workqueue. 5. Retry immediately (due to virtio_mem_retry()), go to 1. The result are endless retries. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-16-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: drop last_mb_idDavid Hildenbrand1-4/+0
No longer used, let's drop it. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-15-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: generalize virtio_mem_overlaps_range()David Hildenbrand1-7/+3
Avoid using memory block ids. While at it, use uint64_t for address/size. This is a preparation for Big Block Mode (BBM). Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-14-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: generalize virtio_mem_owned_mb()David Hildenbrand1-4/+5
Avoid using memory block ids. Rename it to virtio_mem_contains_range(). This is a preparation for Big Block Mode (BBM). Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-13-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: generalize check for added memoryDavid Hildenbrand1-4/+15
Let's check by traversing busy system RAM resources instead, to avoid relying on memory block states. Don't use walk_system_ram_range(), as that works on pages and we want to use the bare addresses we have easily at hand. This is a preparation for Big Block Mode (BBM), which won't have memory block states. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-12-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: retry fake-offlining via alloc_contig_range() on ZONE_MOVABLEDavid Hildenbrand1-11/+26
ZONE_MOVABLE is supposed to give some guarantees, yet, alloc_contig_range() isn't prepared to properly deal with some racy cases properly (e.g., temporary page pinning when exiting processed, PCP). Retry 5 times for now. There is certainly room for improvement in the future. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-11-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: factor out handling of fake-offline pages in memory notifierDavid Hildenbrand1-23/+50
Let's factor out the core pieces and place the implementation next to virtio_mem_fake_offline(). We'll reuse this functionality soon. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-10-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: factor out fake-offlining into virtio_mem_fake_offline()David Hildenbrand1-10/+24
... which now matches virtio_mem_fake_online(). We'll reuse this functionality soon. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-9-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: print debug messages from virtio_mem_send_*_request()David Hildenbrand1-15/+35
Let's move the existing dev_dbg() into the functions, print if something went wrong, and also print for virtio_mem_send_unplug_all_request(). Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-8-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: factor out calculation of the bit number within the subblock bitmapDavid Hildenbrand1-5/+15
The calculation is already complicated enough, let's limit it to one location. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-7-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: use "unsigned long" for nr_pages when fake onlining/offliningDavid Hildenbrand1-4/+4
No harm done, but let's be consistent. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-6-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: drop rc2 in virtio_mem_mb_plug_and_add()David Hildenbrand1-3/+2
We can drop rc2, we don't actually need the value. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-5-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: simplify MAX_ORDER - 1 / pageblock_order handlingDavid Hildenbrand1-16/+19
Let's use pageblock_nr_pages and MAX_ORDER_NR_PAGES instead where possible to simplify. Add a comment why we have that restriction for now. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-4-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: more precise calculation in virtio_mem_mb_state_prepare_next_mb()David Hildenbrand1-4/+2
We actually need one byte less (next_mb_id is exclusive, first_mb_id is inclusive). While at it, compact the code. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-3-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18virtio-mem: determine nid only once using memory_add_physaddr_to_nid()David Hildenbrand1-17/+11
Let's determine the target nid only once in case we have none specified - usually, we'll end up with node 0 either way. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-10-23Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-1/+1
Pull virtio updates from Michael Tsirkin: "vhost, vdpa, and virtio cleanups and fixes A very quiet cycle, no new features" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: MAINTAINERS: add URL for virtio-mem vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call vringh: fix __vringh_iov() when riov and wiov are different vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK s390: virtio: PV needs VIRTIO I/O device protection virtio: let arch advertise guest's memory access restrictions vhost_vdpa: Fix duplicate included kernel.h vhost: reduce stack usage in log_used virtio-mem: Constify mem_id_table virtio_input: Constify id_table virtio-balloon: Constify id_table vdpa/mlx5: Fix failure to bring link up vdpa/mlx5: Make use of a specific 16 bit endianness API
2020-10-21virtio-mem: Constify mem_id_tableRikard Falkeborn1-1/+1
mem_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/20200911203509.26505-4-rikard.falkeborn@gmail.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-10-16virtio-mem: try to merge system ram resourcesDavid Hildenbrand1-1/+2
virtio-mem adds memory in memory block granularity, to be able to remove it in the same granularity again later, and to grow slowly on demand. This, however, results in quite a lot of resources when adding a lot of memory. Resources are effectively stored in a list-based tree. Having a lot of resources not only wastes memory, it also makes traversing that tree more expensive, and makes /proc/iomem explode in size (e.g., requiring kexec-tools to manually merge resources later when e.g., trying to create a kdump header). Before this patch, we get (/proc/iomem) when hotplugging 2G via virtio-mem on x86-64: [...] 100000000-13fffffff : System RAM 140000000-33fffffff : virtio0 140000000-147ffffff : System RAM (virtio_mem) 148000000-14fffffff : System RAM (virtio_mem) 150000000-157ffffff : System RAM (virtio_mem) 158000000-15fffffff : System RAM (virtio_mem) 160000000-167ffffff : System RAM (virtio_mem) 168000000-16fffffff : System RAM (virtio_mem) 170000000-177ffffff : System RAM (virtio_mem) 178000000-17fffffff : System RAM (virtio_mem) 180000000-187ffffff : System RAM (virtio_mem) 188000000-18fffffff : System RAM (virtio_mem) 190000000-197ffffff : System RAM (virtio_mem) 198000000-19fffffff : System RAM (virtio_mem) 1a0000000-1a7ffffff : System RAM (virtio_mem) 1a8000000-1afffffff : System RAM (virtio_mem) 1b0000000-1b7ffffff : System RAM (virtio_mem) 1b8000000-1bfffffff : System RAM (virtio_mem) 3280000000-32ffffffff : PCI Bus 0000:00 With this patch, we get (/proc/iomem): [...] fffc0000-ffffffff : Reserved 100000000-13fffffff : System RAM 140000000-33fffffff : virtio0 140000000-1bfffffff : System RAM (virtio_mem) 3280000000-32ffffffff : PCI Bus 0000:00 Of course, with more hotplugged memory, it gets worse. When unplugging memory blocks again, try_remove_memory() (via offline_and_remove_memory()) will properly split the resource up again. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.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: Dave Jiang <dave.jiang@intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Grall <julien@xen.org> Cc: Kees Cook <keescook@chromium.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> 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: 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: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20200911103459.10306-7-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>
2020-10-13virtio-mem: don't special-case ZONE_MOVABLEDavid Hildenbrand1-39/+8
When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather unclear, which is why we special-cased ZONE_MOVABLE such that partially plugged blocks would never end up in ZONE_MOVABLE. Now that the semantics are much clearer (and will be documented in a follow-up patch including the new virtio-mem behavior), let's allow to online partially plugged memory blocks to ZONE_MOVABLE and also consider memory blocks that were onlined to ZONE_MOVABLE when unplugging memory. While unplugged memory pages are, in general, unmovable, they can be skipped when offlining memory. virtio-mem only unplugs fairly big chunks (in the megabyte range) and rather tries to shrink the memory region than randomly choosing memory. In theory, if all other pages in the movable zone would be movable, virtio-mem would only shrink that zone and not create any kind of fragmentation. In the future, we might want to remember the zone again and use the information when (un)plugging memory. For now, let's keep it simple. Note: Support for defragmentation is planned, to deal with fragmentation after unplug due to memory chunks within memory blocks that could not get unplugged before (e.g., somebody pinning pages within ZONE_MOVABLE for a longer time). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Qian Cai <cai@lca.pw> Link: http://lkml.kernel.org/r/20200816125333.7434-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-05virtio_mem: convert to LE accessorsMichael S. Tsirkin1-15/+15
Virtio mem is modern-only. Use LE accessors for config space. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>