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2024-07-03driver core: have match() callback in struct bus_type take a const *Greg Kroah-Hartman2-3/+3
In the match() callback, the struct device_driver * should not be changed, so change the function callback to be a const *. This is one step of many towards making the driver core safe to have struct device_driver in read-only memory. Because the match() callback is in all busses, all busses are modified to handle this properly. This does entail switching some container_of() calls to container_of_const() to properly handle the constant *. For some busses, like PCI and USB and HV, the const * is cast away in the match callback as those busses do want to modify those structures at this point in time (they have a local lock in the driver structure.) That will have to be changed in the future if they wish to have their struct device * in read-only-memory. Cc: Rafael J. Wysocki <rafael@kernel.org> Reviewed-by: Alex Elder <elder@kernel.org> Acked-by: Sumit Garg <sumit.garg@linaro.org> Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-23drivers/xen: Improve the late XenStore init protocolHenry Wang1-13/+23
Currently, the late XenStore init protocol is only triggered properly for the case that HVM_PARAM_STORE_PFN is ~0ULL (invalid). For the case that XenStore interface is allocated but not ready (the connection status is not XENSTORE_CONNECTED), Linux should also wait until the XenStore is set up properly. Introduce a macro to describe the XenStore interface is ready, use it in xenbus_probe_initcall() to select the code path of doing the late XenStore init protocol or not. Since now we have more than one condition for XenStore late init, rework the check in xenbus_probe() for the free_irq(). Take the opportunity to enhance the check of the allocated XenStore interface can be properly mapped, and return error early if the memremap() fails. Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later as HVM domain") Signed-off-by: Henry Wang <xin.wang2@amd.com> Signed-off-by: Michal Orzel <michal.orzel@amd.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20240517011516.1451087-1-xin.wang2@amd.com Signed-off-by: Juergen Gross <jgross@suse.com>
2024-05-17xen/xenbus: Use *-y instead of *-objs in MakefileAndy Shevchenko1-8/+6
*-objs suffix is reserved rather for (user-space) host programs while usually *-y suffix is used for kernel drivers (although *-objs works for that purpose for now). Let's correct the old usages of *-objs in Makefiles. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20240508152658.1445809-1-andriy.shevchenko@linux.intel.com Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-12xen/xenbus: document will_handle argument for xenbus_watch_path()SeongJae Park1-6/+9
Commit 2e85d32b1c86 ("xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()") added will_handle argument to xenbus_watch_path() and its wrapper, xenbus_watch_pathfmt(), but didn't document it on the kerneldoc comments of the function. This is causing warnings that reported by kernel test robot. Add the documentation to fix it. Fixes: 2e85d32b1c86 ("xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202401121154.FI8jDGun-lkp@intel.com/ Signed-off-by: SeongJae Park <sj@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20240112185903.83737-1-sj@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
2024-01-09xen/xenbus: client: fix kernel-doc commentsRandy Dunlap1-25/+34
Correct function kernel-doc notation to prevent warnings from scripts/kernel-doc. xenbus_client.c:134: warning: No description found for return value of 'xenbus_watch_path' xenbus_client.c:177: warning: No description found for return value of 'xenbus_watch_pathfmt' xenbus_client.c:258: warning: missing initial short description on line: * xenbus_switch_state xenbus_client.c:267: warning: No description found for return value of 'xenbus_switch_state' xenbus_client.c:308: warning: missing initial short description on line: * xenbus_dev_error xenbus_client.c:327: warning: missing initial short description on line: * xenbus_dev_fatal xenbus_client.c:350: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps xenbus_client.c:457: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Allocate an event channel for the given xenbus_device, assigning the newly xenbus_client.c:486: warning: expecting prototype for Free an existing event channel. Returns 0 on success or(). Prototype was for xenbus_free_evtchn() instead xenbus_client.c:502: warning: missing initial short description on line: * xenbus_map_ring_valloc xenbus_client.c:517: warning: No description found for return value of 'xenbus_map_ring_valloc' xenbus_client.c:602: warning: missing initial short description on line: * xenbus_unmap_ring xenbus_client.c:614: warning: No description found for return value of 'xenbus_unmap_ring' xenbus_client.c:715: warning: missing initial short description on line: * xenbus_unmap_ring_vfree xenbus_client.c:727: warning: No description found for return value of 'xenbus_unmap_ring_vfree' xenbus_client.c:919: warning: missing initial short description on line: * xenbus_read_driver_state xenbus_client.c:926: warning: No description found for return value of 'xenbus_read_driver_state' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: xen-devel@lists.xenproject.org Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20231206181724.27767-1-rdunlap@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-02Merge tag 'mm-stable-2023-11-01-14-33' of ↵Linus Torvalds1-7/+10
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Kemeng Shi has contributed some compation maintenance work in the series 'Fixes and cleanups to compaction' - Joel Fernandes has a patchset ('Optimize mremap during mutual alignment within PMD') which fixes an obscure issue with mremap()'s pagetable handling during a subsequent exec(), based upon an implementation which Linus suggested - More DAMON/DAMOS maintenance and feature work from SeongJae Park i the following patch series: mm/damon: misc fixups for documents, comments and its tracepoint mm/damon: add a tracepoint for damos apply target regions mm/damon: provide pseudo-moving sum based access rate mm/damon: implement DAMOS apply intervals mm/damon/core-test: Fix memory leaks in core-test mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval - In the series 'Do not try to access unaccepted memory' Adrian Hunter provides some fixups for the recently-added 'unaccepted memory' feature. To increase the feature's checking coverage. 'Plug a few gaps where RAM is exposed without checking if it is unaccepted memory' - In the series 'cleanups for lockless slab shrink' Qi Zheng has done some maintenance work which is preparation for the lockless slab shrinking code - Qi Zheng has redone the earlier (and reverted) attempt to make slab shrinking lockless in the series 'use refcount+RCU method to implement lockless slab shrink' - David Hildenbrand contributes some maintenance work for the rmap code in the series 'Anon rmap cleanups' - Kefeng Wang does more folio conversions and some maintenance work in the migration code. Series 'mm: migrate: more folio conversion and unification' - Matthew Wilcox has fixed an issue in the buffer_head code which was causing long stalls under some heavy memory/IO loads. Some cleanups were added on the way. Series 'Add and use bdev_getblk()' - In the series 'Use nth_page() in place of direct struct page manipulation' Zi Yan has fixed a potential issue with the direct manipulation of hugetlb page frames - In the series 'mm: hugetlb: Skip initialization of gigantic tail struct pages if freed by HVO' has improved our handling of gigantic pages in the hugetlb vmmemmep optimizaton code. This provides significant boot time improvements when significant amounts of gigantic pages are in use - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code rationalization and folio conversions in the hugetlb code - Yin Fengwei has improved mlock()'s handling of large folios in the series 'support large folio for mlock' - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has added statistics for memcg v1 users which are available (and useful) under memcg v2 - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable) prctl so that userspace may direct the kernel to not automatically propagate the denial to child processes. The series is named 'MDWE without inheritance' - Kefeng Wang has provided the series 'mm: convert numa balancing functions to use a folio' which does what it says - In the series 'mm/ksm: add fork-exec support for prctl' Stefan Roesch makes is possible for a process to propagate KSM treatment across exec() - Huang Ying has enhanced memory tiering's calculation of memory distances. This is used to permit the dax/kmem driver to use 'high bandwidth memory' in addition to Optane Data Center Persistent Memory Modules (DCPMM). The series is named 'memory tiering: calculate abstract distance based on ACPI HMAT' - In the series 'Smart scanning mode for KSM' Stefan Roesch has optimized KSM by teaching it to retain and use some historical information from previous scans - Yosry Ahmed has fixed some inconsistencies in memcg statistics in the series 'mm: memcg: fix tracking of pending stats updates values' - In the series 'Implement IOCTL to get and optionally clear info about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap which permits us to atomically read-then-clear page softdirty state. This is mainly used by CRIU - Hugh Dickins contributed the series 'shmem,tmpfs: general maintenance', a bunch of relatively minor maintenance tweaks to this code - Matthew Wilcox has increased the use of the VMA lock over file-backed page faults in the series 'Handle more faults under the VMA lock'. Some rationalizations of the fault path became possible as a result - In the series 'mm/rmap: convert page_move_anon_rmap() to folio_move_anon_rmap()' David Hildenbrand has implemented some cleanups and folio conversions - In the series 'various improvements to the GUP interface' Lorenzo Stoakes has simplified and improved the GUP interface with an eye to providing groundwork for future improvements - Andrey Konovalov has sent along the series 'kasan: assorted fixes and improvements' which does those things - Some page allocator maintenance work from Kemeng Shi in the series 'Two minor cleanups to break_down_buddy_pages' - In thes series 'New selftest for mm' Breno Leitao has developed another MM self test which tickles a race we had between madvise() and page faults - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups and an optimization to the core pagecache code - Nhat Pham has added memcg accounting for hugetlb memory in the series 'hugetlb memcg accounting' - Cleanups and rationalizations to the pagemap code from Lorenzo Stoakes, in the series 'Abstract vma_merge() and split_vma()' - Audra Mitchell has fixed issues in the procfs page_owner code's new timestamping feature which was causing some misbehaviours. In the series 'Fix page_owner's use of free timestamps' - Lorenzo Stoakes has fixed the handling of new mappings of sealed files in the series 'permit write-sealed memfd read-only shared mappings' - Mike Kravetz has optimized the hugetlb vmemmap optimization in the series 'Batch hugetlb vmemmap modification operations' - Some buffer_head folio conversions and cleanups from Matthew Wilcox in the series 'Finish the create_empty_buffers() transition' - As a page allocator performance optimization Huang Ying has added automatic tuning to the allocator's per-cpu-pages feature, in the series 'mm: PCP high auto-tuning' - Roman Gushchin has contributed the patchset 'mm: improve performance of accounted kernel memory allocations' which improves their performance by ~30% as measured by a micro-benchmark - folio conversions from Kefeng Wang in the series 'mm: convert page cpupid functions to folios' - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about kmemleak' - Qi Zheng has improved our handling of memoryless nodes by keeping them off the allocation fallback list. This is done in the series 'handle memoryless nodes more appropriately' - khugepaged conversions from Vishal Moola in the series 'Some khugepaged folio conversions'" [ bcachefs conflicts with the dynamically allocated shrinkers have been resolved as per Stephen Rothwell in https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/ with help from Qi Zheng. The clone3 test filtering conflict was half-arsed by yours truly ] * tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits) mm/damon/sysfs: update monitoring target regions for online input commit mm/damon/sysfs: remove requested targets when online-commit inputs selftests: add a sanity check for zswap Documentation: maple_tree: fix word spelling error mm/vmalloc: fix the unchecked dereference warning in vread_iter() zswap: export compression failure stats Documentation: ubsan: drop "the" from article title mempolicy: migration attempt to match interleave nodes mempolicy: mmap_lock is not needed while migrating folios mempolicy: alloc_pages_mpol() for NUMA policy without vma mm: add page_rmappable_folio() wrapper mempolicy: remove confusing MPOL_MF_LAZY dead code mempolicy: mpol_shared_policy_init() without pseudo-vma mempolicy trivia: use pgoff_t in shared mempolicy tree mempolicy trivia: slightly more consistent naming mempolicy trivia: delete those ancient pr_debug()s mempolicy: fix migrate_pages(2) syscall return nr_failed kernfs: drop shared NUMA mempolicy hooks hugetlbfs: drop shared NUMA mempolicy pretence mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets() ...
2023-10-16xen/xenbus: Add __counted_by for struct read_buffer and use struct_size()Gustavo A. R. Silva1-2/+2
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jason Andryuk <jandryuk@gmail.com> Link: https://lore.kernel.org/r/ZSRMosLuJJS5Y/io@work Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-16xenbus: fix error exit in xenbus_init()Juergen Gross1-1/+1
In case an error occurs in xenbus_init(), xen_store_domain_type should be set to XS_UNKNOWN. Fix one instance where this action is missing. Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later as HVM domain") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Link: https://lore.kernel.org/r/202304200845.w7m4kXZr-lkp@intel.com/ Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/20230822091138.4765-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-04xenbus/backend: dynamically allocate the xen-backend shrinkerQi Zheng1-7/+10
Use new APIs to dynamically allocate the xen-backend shrinker. Link: https://lkml.kernel.org/r/20230911094444.68966-6-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22xen/xenbus: Avoid a lockdep warning when adding a watchPetr Pavlu1-2/+2
The following lockdep warning appears during boot on a Xen dom0 system: [ 96.388794] ====================================================== [ 96.388797] WARNING: possible circular locking dependency detected [ 96.388799] 6.4.0-rc5-default+ #8 Tainted: G EL [ 96.388803] ------------------------------------------------------ [ 96.388804] xenconsoled/1330 is trying to acquire lock: [ 96.388808] ffffffff82acdd10 (xs_watch_rwsem){++++}-{3:3}, at: register_xenbus_watch+0x45/0x140 [ 96.388847] but task is already holding lock: [ 96.388849] ffff888100c92068 (&u->msgbuffer_mutex){+.+.}-{3:3}, at: xenbus_file_write+0x2c/0x600 [ 96.388862] which lock already depends on the new lock. [ 96.388864] the existing dependency chain (in reverse order) is: [ 96.388866] -> #2 (&u->msgbuffer_mutex){+.+.}-{3:3}: [ 96.388874] __mutex_lock+0x85/0xb30 [ 96.388885] xenbus_dev_queue_reply+0x48/0x2b0 [ 96.388890] xenbus_thread+0x1d7/0x950 [ 96.388897] kthread+0xe7/0x120 [ 96.388905] ret_from_fork+0x2c/0x50 [ 96.388914] -> #1 (xs_response_mutex){+.+.}-{3:3}: [ 96.388923] __mutex_lock+0x85/0xb30 [ 96.388930] xenbus_backend_ioctl+0x56/0x1c0 [ 96.388935] __x64_sys_ioctl+0x90/0xd0 [ 96.388942] do_syscall_64+0x5c/0x90 [ 96.388950] entry_SYSCALL_64_after_hwframe+0x72/0xdc [ 96.388957] -> #0 (xs_watch_rwsem){++++}-{3:3}: [ 96.388965] __lock_acquire+0x1538/0x2260 [ 96.388972] lock_acquire+0xc6/0x2b0 [ 96.388976] down_read+0x2d/0x160 [ 96.388983] register_xenbus_watch+0x45/0x140 [ 96.388990] xenbus_file_write+0x53d/0x600 [ 96.388994] vfs_write+0xe4/0x490 [ 96.389003] ksys_write+0xb8/0xf0 [ 96.389011] do_syscall_64+0x5c/0x90 [ 96.389017] entry_SYSCALL_64_after_hwframe+0x72/0xdc [ 96.389023] other info that might help us debug this: [ 96.389025] Chain exists of: xs_watch_rwsem --> xs_response_mutex --> &u->msgbuffer_mutex [ 96.413429] Possible unsafe locking scenario: [ 96.413430] CPU0 CPU1 [ 96.413430] ---- ---- [ 96.413431] lock(&u->msgbuffer_mutex); [ 96.413432] lock(xs_response_mutex); [ 96.413433] lock(&u->msgbuffer_mutex); [ 96.413434] rlock(xs_watch_rwsem); [ 96.413436] *** DEADLOCK *** [ 96.413436] 1 lock held by xenconsoled/1330: [ 96.413438] #0: ffff888100c92068 (&u->msgbuffer_mutex){+.+.}-{3:3}, at: xenbus_file_write+0x2c/0x600 [ 96.413446] An ioctl call IOCTL_XENBUS_BACKEND_SETUP (record #1 in the report) results in calling xenbus_alloc() -> xs_suspend() which introduces ordering xs_watch_rwsem --> xs_response_mutex. The xenbus_thread() operation (record #2) creates xs_response_mutex --> &u->msgbuffer_mutex. An XS_WATCH write to the xenbus file then results in a complain about the opposite lock order &u->msgbuffer_mutex --> xs_watch_rwsem. The dependency xs_watch_rwsem --> xs_response_mutex is spurious. Avoid it and the warning by changing the ordering in xs_suspend(), first acquire xs_response_mutex and then xs_watch_rwsem. Reverse also the unlocking order in xs_suspend_cancel() for consistency, but keep xs_resume() as is because it needs to have xs_watch_rwsem unlocked only after exiting xs suspend and re-adding all watches. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20230607123624.15739-1-petr.pavlu@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21xen: xenbus: Use helper function IS_ERR_OR_NULL()Li Zetao1-1/+1
Use IS_ERR_OR_NULL() to detect an error pointer or a null pointer open-coding to simplify the code. Signed-off-by: Li Zetao <lizetao1@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20230817014736.3094289-1-lizetao1@huawei.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-07-25xenbus: check xen_domain in xenbus_probe_initcallStefano Stabellini1-0/+3
The same way we already do in xenbus_init. Fixes the following warning: [ 352.175563] Trying to free already-free IRQ 0 [ 352.177355] WARNING: CPU: 1 PID: 88 at kernel/irq/manage.c:1893 free_irq+0xbf/0x350 [...] [ 352.213951] Call Trace: [ 352.214390] <TASK> [ 352.214717] ? __warn+0x81/0x170 [ 352.215436] ? free_irq+0xbf/0x350 [ 352.215906] ? report_bug+0x10b/0x200 [ 352.216408] ? prb_read_valid+0x17/0x20 [ 352.216926] ? handle_bug+0x44/0x80 [ 352.217409] ? exc_invalid_op+0x13/0x60 [ 352.217932] ? asm_exc_invalid_op+0x16/0x20 [ 352.218497] ? free_irq+0xbf/0x350 [ 352.218979] ? __pfx_xenbus_probe_thread+0x10/0x10 [ 352.219600] xenbus_probe+0x7a/0x80 [ 352.221030] xenbus_probe_thread+0x76/0xc0 Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later as HVM domain") Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com> Tested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2307211609140.3118466@ubuntu-linux-20-04-desktop Signed-off-by: Juergen Gross <jgross@suse.com>
2023-01-27driver core: make struct bus_type.uevent() take a const *Greg Kroah-Hartman2-6/+6
The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-23Merge tag 'for-linus-6.0-rc7-tag' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix from Juergen Gross: "A single fix for an issue in the xenbus driver (initialization of multi-page rings for Xen PV devices)" * tag 'for-linus-6.0-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/xenbus: fix xenbus_setup_ring()
2022-09-16xen/xenbus: fix xenbus_setup_ring()Juergen Gross1-3/+6
Commit 4573240f0764 ("xen/xenbus: eliminate xenbus_grant_ring()") introduced an error for initialization of multi-page rings. Cc: stable@vger.kernel.org Fixes: 4573240f0764 ("xen/xenbus: eliminate xenbus_grant_ring()") Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-08-27Merge tag 'for-linus-6.0-rc3-tag' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: - two minor cleanups - a fix of the xen/privcmd driver avoiding a possible NULL dereference in an error case * tag 'for-linus-6.0-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/privcmd: fix error exit of privcmd_ioctl_dm_op() xen: move from strlcpy with unused retval to strscpy xen: x86: remove setting the obsolete config XEN_MAX_DOMAIN_MEMORY
2022-08-25xen: move from strlcpy with unused retval to strscpyWolfram Sang1-1/+1
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/20220818210122.7613-1-wsa+renesas@sang-engineering.com Signed-off-by: Juergen Gross <jgross@suse.com>
2022-08-14Merge tag 'for-linus-6.0-rc1b-tag' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: - fix the handling of the "persistent grants" feature negotiation between Xen blkfront and Xen blkback drivers - a cleanup of xen.config and adding xen.config to Xen section in MAINTAINERS - support HVMOP_set_evtchn_upcall_vector, which is more compliant to "normal" interrupt handling than the global callback used up to now - further small cleanups * tag 'for-linus-6.0-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: MAINTAINERS: add xen config fragments to XEN HYPERVISOR sections xen: remove XEN_SCRUB_PAGES in xen.config xen/pciback: Fix comment typo xen/xenbus: fix return type in xenbus_file_read() xen-blkfront: Apply 'feature_persistent' parameter when connect xen-blkback: Apply 'feature_persistent' parameter when connect xen-blkback: fix persistent grants negotiation x86/xen: Add support for HVMOP_set_evtchn_upcall_vector
2022-08-12xen/xenbus: fix return type in xenbus_file_read()Dan Carpenter1-2/+2
This code tries to store -EFAULT in an unsigned int. The xenbus_file_read() function returns type ssize_t so the negative value is returned as a positive value to the user. This change forces another change to the min() macro. Originally, the min() macro used "unsigned" type which checkpatch complains about. Also unsigned type would break if "len" were not capped at MAX_RW_COUNT. Use size_t for the min(). (No effect on runtime for the min_t() change). Fixes: 2fb3683e7b16 ("xen: Add xenbus device driver") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/YutxJUaUYRG/VLVc@kili Signed-off-by: Juergen Gross <jgross@suse.com>
2022-07-03mm: shrinkers: provide shrinkers with namesRoman Gushchin1-1/+1
Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-01xen: replace xen_remap() with memremap()Juergen Gross1-4/+4
xen_remap() is used to establish mappings for frames not under direct control of the kernel: for Xenstore and console ring pages, and for grant pages of non-PV guests. Today xen_remap() is defined to use ioremap() on x86 (doing uncached mappings), and ioremap_cache() on Arm (doing cached mappings). Uncached mappings for those use cases are bad for performance, so they should be avoided if possible. As all use cases of xen_remap() don't require uncached mappings (the mapped area is always physical RAM), a mapping using the standard WB cache mode is fine. As sparse is flagging some of the xen_remap() use cases to be not appropriate for iomem(), as the result is not annotated with the __iomem modifier, eliminate xen_remap() completely and replace all use cases with memremap() specifying the MEMREMAP_WB caching mode. xen_unmap() can be replaced with memunmap(). Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20220530082634.6339-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2022-05-27xen: switch gnttab_end_foreign_access() to take a struct page pointerJuergen Gross1-1/+1
Instead of a virtual kernel address use a pointer of the associated struct page as second parameter of gnttab_end_foreign_access(). Most users have that pointer available already and are creating the virtual address from it, risking problems in case the memory is located in highmem. gnttab_end_foreign_access() itself won't need to get the struct page from the address again. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-05-19xen: add support for initializing xenstore later as HVM domainLuca Miccio1-20/+71
When running as dom0less guest (HVM domain on ARM) the xenstore event channel is available at domain creation but the shared xenstore interface page only becomes available later on. In that case, wait for a notification on the xenstore event channel, then complete the xenstore initialization later, when the shared page is actually available. The xenstore page has few extra field. Add them to the shared struct. One of the field is "connection", when the connection is ready, it is zero. If the connection is not-zero, wait for a notification. Signed-off-by: Luca Miccio <lucmiccio@gmail.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20220513211938.719341-2-sstabellini@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
2022-05-19xen/xenbus: eliminate xenbus_grant_ring()Juergen Gross1-46/+19
There is no external user of xenbus_grant_ring() left, so merge it into the only caller xenbus_setup_ring(). Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-05-19xen/xenbus: add xenbus_setup_ring() service functionJuergen Gross1-0/+69
Most PV device frontends share very similar code for setting up shared ring buffers: - allocate page(s) - init the ring admin data - give the backend access to the ring via grants Tearing down the ring requires similar actions in all frontends again: - remove grants - free the page(s) Provide service functions xenbus_setup_ring() and xenbus_teardown_ring() for that purpose. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-03-07xen/xenbus: don't let xenbus_grant_ring() remove grants in error caseJuergen Gross1-13/+11
Letting xenbus_grant_ring() tear down grants in the error case is problematic, as the other side could already have used these grants. Calling gnttab_end_foreign_access_ref() without checking success is resulting in an unclear situation for any caller of xenbus_grant_ring() as in the error case the memory pages of the ring page might be partially mapped. Freeing them would risk unwanted foreign access to them, while not freeing them would leak memory. In order to remove the need to undo any gnttab_grant_foreign_access() calls, use gnttab_alloc_grant_references() to make sure no further error can occur in the loop granting access to the ring pages. It should be noted that this way of handling removes leaking of grant entries in the error case, too. This is CVE-2022-23040 / part of XSA-396. Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
2021-11-24xen: detect uninitialized xenbus in xenbus_initStefano Stabellini1-0/+23
If the xenstore page hasn't been allocated properly, reading the value of the related hvm_param (HVM_PARAM_STORE_PFN) won't actually return error. Instead, it will succeed and return zero. Instead of attempting to xen_remap a bad guest physical address, detect this condition and return early. Note that although a guest physical address of zero for HVM_PARAM_STORE_PFN is theoretically possible, it is not a good choice and zero has never been validly used in that capacity. Also recognize all bits set as an invalid value. For 32-bit Linux, any pfn above ULONG_MAX would get truncated. Pfns above ULONG_MAX should never be passed by the Xen tools to HVM guests anyway, so check for this condition and return early. Cc: stable@vger.kernel.org Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20211123210748.1910236-1-sstabellini@kernel.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-11-23xen: add "not_essential" flag to struct xenbus_driverJuergen Gross1-11/+3
When booting the xenbus driver will wait for PV devices to have connected to their backends before continuing. The timeout is different between essential and non-essential devices. Non-essential devices are identified by their nodenames directly in the xenbus driver, which requires to update this list in case a new device type being non-essential is added (this was missed for several types in the past). In order to avoid this problem, add a "not_essential" flag to struct xenbus_driver which can be set to "true" by the respective frontend. Set this flag for the frontends currently regarded to be not essential (vkbs and vfb) and use it for testing in the xenbus driver. Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20211022064800.14978-2-jgross@suse.com Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-11-16xen: don't continue xenstore initialization in case of errorsStefano Stabellini1-1/+3
In case of errors in xenbus_init (e.g. missing xen_store_gfn parameter), we goto out_error but we forget to reset xen_store_domain_type to XS_UNKNOWN. As a consequence xenbus_probe_initcall and other initcalls will still try to initialize xenstore resulting into a crash at boot. [ 2.479830] Call trace: [ 2.482314] xb_init_comms+0x18/0x150 [ 2.486354] xs_init+0x34/0x138 [ 2.489786] xenbus_probe+0x4c/0x70 [ 2.498432] xenbus_probe_initcall+0x2c/0x7c [ 2.503944] do_one_initcall+0x54/0x1b8 [ 2.507358] kernel_init_freeable+0x1ac/0x210 [ 2.511617] kernel_init+0x28/0x130 [ 2.516112] ret_from_fork+0x10/0x20 Cc: <Stable@vger.kernel.org> Cc: jbeulich@suse.com Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Link: https://lore.kernel.org/r/20211115222719.2558207-1-sstabellini@kernel.org Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-09-02Merge tag 'for-linus-5.15-rc1-tag' of ↵Linus Torvalds1-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - some small cleanups - a fix for a bug when running as Xen PV guest which could result in not all memory being transferred in case of a migration of the guest - a small series for getting rid of code for supporting very old Xen hypervisor versions nobody should be using since many years now - a series for hardening the Xen block frontend driver - a fix for Xen PV boot code issuing warning messages due to a stray preempt_disable() on the non-boot processors * tag 'for-linus-5.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: remove stray preempt_disable() from PV AP startup code xen/pcifront: Removed unnecessary __ref annotation x86: xen: platform-pci-unplug: use pr_err() and pr_warn() instead of raw printk() drivers/xen/xenbus/xenbus_client.c: fix bugon.cocci warnings xen/blkfront: don't trust the backend response data blindly xen/blkfront: don't take local copy of a request from the ring page xen/blkfront: read response from backend only once xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guests xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests xen: check required Xen features xen: fix setting of max_pfn in shared_info
2021-08-30drivers/xen/xenbus/xenbus_client.c: fix bugon.cocci warningsJing Yangyang1-6/+3
Use BUG_ON instead of a if condition followed by BUG. Generated by: scripts/coccinelle/misc/bugon.cocci Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Jing Yangyang <jing.yangyang@zte.com.cn> Reviewed-by: SeongJae Park <sjpark@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20210825062451.69998-1-deng.changcheng@zte.com.cn Signed-off-by: Juergen Gross <jgross@suse.com>
2021-07-21bus: Make remove callback return voidUwe Kleine-König2-4/+2
The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix <trix@redhat.com> (For fpga) Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts) Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb) Acked-by: Pali Rohár <pali@kernel.org> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media) Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform) Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-By: Vinod Koul <vkoul@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> (For xen) Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd) Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb) Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus) Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio) Acked-by: Maximilian Luz <luzmaximilian@gmail.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack) Acked-by: Geoff Levand <geoff@infradead.org> (For ps3) Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt) Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th) Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia) Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI) Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr) Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid) Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa) Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire) Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid) Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox) Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss) Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC) Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-05xen: Use DEVICE_ATTR_*() macroYueHaibing1-8/+7
Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(), which makes the code a bit shorter and easier to read. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210526141019.13752-1-yuehaibing@huawei.com Signed-off-by: Juergen Gross <jgross@suse.com>
2021-02-23xen/events: add per-xenbus device event statistics and settingsJuergen Gross1-0/+66
Add syfs nodes for each xenbus device showing event statistics (number of events and spurious events, number of associated event channels) and for setting a spurious event threshold in case a frontend is sending too many events without being rogue on purpose. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>