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2024-02-13xen/events: close evtchn after mapping cleanupMaximilian Heyne
shutdown_pirq and startup_pirq are not taking the irq_mapping_update_lock because they can't due to lock inversion. Both are called with the irq_desc->lock being taking. The lock order, however, is first irq_mapping_update_lock and then irq_desc->lock. This opens multiple races: - shutdown_pirq can be interrupted by a function that allocates an event channel: CPU0 CPU1 shutdown_pirq { xen_evtchn_close(e) __startup_pirq { EVTCHNOP_bind_pirq -> returns just freed evtchn e set_evtchn_to_irq(e, irq) } xen_irq_info_cleanup() { set_evtchn_to_irq(e, -1) } } Assume here event channel e refers here to the same event channel number. After this race the evtchn_to_irq mapping for e is invalid (-1). - __startup_pirq races with __unbind_from_irq in a similar way. Because __startup_pirq doesn't take irq_mapping_update_lock it can grab the evtchn that __unbind_from_irq is currently freeing and cleaning up. In this case even though the event channel is allocated, its mapping can be unset in evtchn_to_irq. The fix is to first cleanup the mappings and then close the event channel. In this way, when an event channel gets allocated it's potential previous evtchn_to_irq mappings are guaranteed to be unset already. This is also the reverse order of the allocation where first the event channel is allocated and then the mappings are setup. On a 5.10 kernel prior to commit 3fcdaf3d7634 ("xen/events: modify internal [un]bind interfaces"), we hit a BUG like the following during probing of NVMe devices. The issue is that during nvme_setup_io_queues, pci_free_irq is called for every device which results in a call to shutdown_pirq. With many nvme devices it's therefore likely to hit this race during boot because there will be multiple calls to shutdown_pirq and startup_pirq are running potentially in parallel. ------------[ cut here ]------------ blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled kernel BUG at drivers/xen/events/events_base.c:499! invalid opcode: 0000 [#1] SMP PTI CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1 Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006 Workqueue: nvme-reset-wq nvme_reset_work RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0 Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00 RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006 RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? show_trace_log_lvl+0x1c1/0x2d9 ? show_trace_log_lvl+0x1c1/0x2d9 ? set_affinity_irq+0xdc/0x1c0 ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0x90/0x110 ? bind_evtchn_to_cpu+0xdf/0xf0 ? do_error_trap+0x65/0x80 ? bind_evtchn_to_cpu+0xdf/0xf0 ? exc_invalid_op+0x4e/0x70 ? bind_evtchn_to_cpu+0xdf/0xf0 ? asm_exc_invalid_op+0x12/0x20 ? bind_evtchn_to_cpu+0xdf/0xf0 ? bind_evtchn_to_cpu+0xc5/0xf0 set_affinity_irq+0xdc/0x1c0 irq_do_set_affinity+0x1d7/0x1f0 irq_setup_affinity+0xd6/0x1a0 irq_startup+0x8a/0xf0 __setup_irq+0x639/0x6d0 ? nvme_suspend+0x150/0x150 request_threaded_irq+0x10c/0x180 ? nvme_suspend+0x150/0x150 pci_request_irq+0xa8/0xf0 ? __blk_mq_free_request+0x74/0xa0 queue_request_irq+0x6f/0x80 nvme_create_queue+0x1af/0x200 nvme_create_io_queues+0xbd/0xf0 nvme_setup_io_queues+0x246/0x320 ? nvme_irq_check+0x30/0x30 nvme_reset_work+0x1c8/0x400 process_one_work+0x1b0/0x350 worker_thread+0x49/0x310 ? process_one_work+0x350/0x350 kthread+0x11b/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x22/0x30 Modules linked in: ---[ end trace a11715de1eee1873 ]--- Fixes: d46a78b05c0e ("xen: implement pirq type event channels") Cc: stable@vger.kernel.org Co-debugged-by: Andrew Panyakin <apanyaki@amazon.com> Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20240124163130.31324-1-mheyne@amazon.de Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-13xen/gntalloc: Replace UAPI 1-element arrayKees Cook
Without changing the structure size (since it is UAPI), add a proper flexible array member, and reference it in the kernel so that it will not be trip the array-bounds sanitizer[1]. Link: https://github.com/KSPP/linux/issues/113 [1] Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: xen-devel@lists.xenproject.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20240206170320.work.437-kees@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-13xen: balloon: make balloon_subsys constRicardo B. Marliere
Now that the driver core can properly handle constant struct bus_type, move the balloon_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240203-bus_cleanup-xen-v1-2-c2f5fe89ed95@marliere.net Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-13xen: pcpu: make xen_pcpu_subsys constRicardo B. Marliere
Now that the driver core can properly handle constant struct bus_type, move the xen_pcpu_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240203-bus_cleanup-xen-v1-1-c2f5fe89ed95@marliere.net Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-13xen/privcmd: Use memdup_array_user() in alloc_ioreq()Markus Elfring
* The function “memdup_array_user” was added with the commit 313ebe47d75558511aa1237b6e35c663b5c0ec6f ("string.h: add array-wrappers for (v)memdup_user()"). Thus use it accordingly. This issue was detected by using the Coccinelle software. * Delete a label which became unnecessary with this refactoring. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/41e333f7-1f3a-41b6-a121-a3c0ae54e36f@web.de Signed-off-by: Juergen Gross <jgross@suse.com>
2024-02-12xen/xenbus: document will_handle argument for xenbus_watch_path()SeongJae Park
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>
2024-01-17Merge tag 'for-linus-6.8-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - update some Xen PV interface related headers - fix some kernel-doc comments in the xenbus driver - fix the Xen gntdev driver to not access the struct page of pages imported from a DMA-buf * tag 'for-linus-6.8-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/gntdev: Fix the abuse of underlying struct page in DMA-buf import xen/xenbus: client: fix kernel-doc comments xen: update PV-device interface headers
2024-01-10xen/gntdev: Fix the abuse of underlying struct page in DMA-buf importOleksandr Tyshchenko
DO NOT access the underlying struct page of an sg table exported by DMA-buf in dmabuf_imp_to_refs(), this is not allowed. Please see drivers/dma-buf/dma-buf.c:mangle_sg_table() for details. Fortunately, here (for special Xen device) we can avoid using pages and calculate gfns directly from dma addresses provided by the sg table. Suggested-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Acked-by: Daniel Vetter <daniel@ffwll.ch> Link: https://lore.kernel.org/r/20240107103426.2038075-1-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
2024-01-09xen/xenbus: client: fix kernel-doc commentsRandy Dunlap
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>
2024-01-08Merge tag 'vfs-6.8.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual fses. Features: - Add Jan Kara as VFS reviewer - Show correct device and inode numbers in proc/<pid>/maps for vma files on stacked filesystems. This is now easily doable thanks to the backing file work from the last cycles. This comes with selftests Cleanups: - Remove a redundant might_sleep() from wait_on_inode() - Initialize pointer with NULL, not 0 - Clarify comment on access_override_creds() - Rework and simplify eventfd_signal() and eventfd_signal_mask() helpers - Process aio completions in batches to avoid needless wakeups - Completely decouple struct mnt_idmap from namespaces. We now only keep the actual idmapping around and don't stash references to namespaces - Reformat maintainer entries to indicate that a given subsystem belongs to fs/ - Simplify fput() for files that were never opened - Get rid of various pointless file helpers - Rename various file helpers - Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from last cycle - Make relatime_need_update() return bool - Use GFP_KERNEL instead of GFP_USER when allocating superblocks - Replace deprecated ida_simple_*() calls with their current ida_*() counterparts Fixes: - Fix comments on user namespace id mapping helpers. They aren't kernel doc comments so they shouldn't be using /** - s/Retuns/Returns/g in various places - Add missing parameter documentation on can_move_mount_beneath() - Rename i_mapping->private_data to i_mapping->i_private_data - Fix a false-positive lockdep warning in pipe_write() for watch queues - Improve __fget_files_rcu() code generation to improve performance - Only notify writer that pipe resizing has finished after setting pipe->max_usage otherwise writers are never notified that the pipe has been resized and hang - Fix some kernel docs in hfsplus - s/passs/pass/g in various places - Fix kernel docs in ntfs - Fix kcalloc() arguments order reported by gcc 14 - Fix uninitialized value in reiserfs" * tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits) reiserfs: fix uninit-value in comp_keys watch_queue: fix kcalloc() arguments order ntfs: dir.c: fix kernel-doc function parameter warnings fs: fix doc comment typo fs tree wide selftests/overlayfs: verify device and inode numbers in /proc/pid/maps fs/proc: show correct device and inode numbers in /proc/pid/maps eventfd: Remove usage of the deprecated ida_simple_xx() API fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation fs/hfsplus: wrapper.c: fix kernel-doc warnings fs: add Jan Kara as reviewer fs/inode: Make relatime_need_update return bool pipe: wakeup wr_wait after setting max_usage file: remove __receive_fd() file: stop exposing receive_fd_user() fs: replace f_rcuhead with f_task_work file: remove pointless wrapper file: s/close_fd_get_file()/file_close_fd()/g Improve __fget_files_rcu() code generation (and thus __fget_light()) file: massage cleanup of files that failed to open fs/pipe: Fix lockdep false-positive in watchqueue pipe_write() ...
2023-11-28eventfd: simplify eventfd_signal()Christian Brauner
Ever since the eventfd type was introduced back in 2007 in commit e1ad7468c77d ("signal/timer/event: eventfd core") the eventfd_signal() function only ever passed 1 as a value for @n. There's no point in keeping that additional argument. Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org Acked-by: Xu Yilun <yilun.xu@intel.com> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> # ocxl Acked-by: Eric Farman <farman@linux.ibm.com> # s390 Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-11-28xen/events: fix error code in xen_bind_pirq_msi_to_irq()Dan Carpenter
Return -ENOMEM if xen_irq_init() fails. currently the code returns an uninitialized variable or zero. Fixes: 5dd9ad32d775 ("xen/events: drop xen_allocate_irqs_dynamic()") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Juergen Gross <jgross@ssue.com> Link: https://lore.kernel.org/r/3b9ab040-a92e-4e35-b687-3a95890a9ace@moroto.mountain Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-17xen: privcmd: Replace zero-length array with flex-array member and use ↵Gustavo A. R. Silva
__counted_by Fake flexible arrays (zero-length and one-element arrays) are deprecated, and should be replaced by flexible-array members. So, replace zero-length array with a flexible-array member in `struct privcmd_kernel_ioreq`. Also annotate array `ports` with `__counted_by()` to 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). This fixes multiple -Warray-bounds warnings: drivers/xen/privcmd.c:1239:30: warning: array subscript i is outside array bounds of 'struct ioreq_port[0]' [-Warray-bounds=] drivers/xen/privcmd.c:1240:30: warning: array subscript i is outside array bounds of 'struct ioreq_port[0]' [-Warray-bounds=] drivers/xen/privcmd.c:1241:30: warning: array subscript i is outside array bounds of 'struct ioreq_port[0]' [-Warray-bounds=] drivers/xen/privcmd.c:1245:33: warning: array subscript i is outside array bounds of 'struct ioreq_port[0]' [-Warray-bounds=] drivers/xen/privcmd.c:1258:67: warning: array subscript i is outside array bounds of 'struct ioreq_port[0]' [-Warray-bounds=] This results in no differences in binary output. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/ZVZlg3tPMPCRdteh@work Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-17swiotlb-xen: provide the "max_mapping_size" methodKeith Busch
There's a bug that when using the XEN hypervisor with bios with large multi-page bio vectors on NVMe, the kernel deadlocks [1]. The deadlocks are caused by inability to map a large bio vector - dma_map_sgtable always returns an error, this gets propagated to the block layer as BLK_STS_RESOURCE and the block layer retries the request indefinitely. XEN uses the swiotlb framework to map discontiguous pages into contiguous runs that are submitted to the PCIe device. The swiotlb framework has a limitation on the length of a mapping - this needs to be announced with the max_mapping_size method to make sure that the hardware drivers do not create larger mappings. Without max_mapping_size, the NVMe block driver would create large mappings that overrun the maximum mapping size. Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Link: https://lore.kernel.org/stable/ZTNH0qtmint%2FzLJZ@mail-itl/ [1] Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Suggested-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/151bef41-e817-aea9-675-a35fdac4ed@redhat.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-15xen/events: remove some info_for_irq() calls in pirq handlingJuergen Gross
Instead of the IRQ number user the struct irq_info pointer as parameter in the internal pirq related functions. This allows to drop some calls of info_for_irq(). Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-15xen/events: modify internal [un]bind interfacesJuergen Gross
Modify the internal bind- and unbind-interfaces to take a struct irq_info parameter. When allocating a new IRQ pass the pointer from the allocating function further up. This will reduce the number of info_for_irq() calls and make the code more efficient. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-15xen/events: drop xen_allocate_irqs_dynamic()Juergen Gross
Instead of having a common function for allocating a single IRQ or a consecutive number of IRQs, split up the functionality into the callers of xen_allocate_irqs_dynamic(). This allows to handle any allocation error in xen_irq_init() gracefully instead of panicing the system. Let xen_irq_init() return the irq_info pointer or NULL in case of an allocation error. Additionally set the IRQ into irq_info already at allocation time, as otherwise the IRQ would be '0' (which is a valid IRQ number) until being set. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-14xen/events: remove some simple helpers from events_base.cJuergen Gross
The helper functions type_from_irq() and cpu_from_irq() are just one line functions used only internally. Open code them where needed. At the same time modify and rename get_evtchn_to_irq() to return a struct irq_info instead of the IRQ number. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-14xen/events: reduce externally visible helper functionsJuergen Gross
get_evtchn_to_irq() has only one external user while irq_from_evtchn() provides the same functionality and is exported for a wider user base. Modify the only external user of get_evtchn_to_irq() to use irq_from_evtchn() instead and make get_evtchn_to_irq() static. evtchn_from_irq() and irq_from_virq() have a single external user and can easily be combined to a new helper irq_evtchn_from_virq() allowing to drop irq_from_virq() and to make evtchn_from_irq() static. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-13xen/events: remove unused functionsJuergen Gross
There are no users of xen_irq_from_pirq() and xen_set_irq_pending(). Remove those functions. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-13xen/events: fix delayed eoi list handlingJuergen Gross
When delaying eoi handling of events, the related elements are queued into the percpu lateeoi list. In case the list isn't empty, the elements should be sorted by the time when eoi handling is to happen. Unfortunately a new element will never be queued at the start of the list, even if it has a handling time lower than all other list elements. Fix that by handling that case the same way as for an empty list. Fixes: e99502f76271 ("xen/events: defer eoi in case of excessive number of events") Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-13xen/shbuf: eliminate 17 kernel-doc warningsRandy Dunlap
Don't use kernel-doc markers ("/**") for comments that are not in kernel-doc format. This prevents multiple kernel-doc warnings: xen-front-pgdir-shbuf.c:25: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * This structure represents the structure of a shared page xen-front-pgdir-shbuf.c:37: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Shared buffer ops which are differently implemented xen-front-pgdir-shbuf.c:65: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Get granted reference to the very first page of the xen-front-pgdir-shbuf.c:85: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Map granted references of the shared buffer. xen-front-pgdir-shbuf.c:106: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Unmap granted references of the shared buffer. xen-front-pgdir-shbuf.c:127: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Free all the resources of the shared buffer. xen-front-pgdir-shbuf.c:154: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Get the number of pages the page directory consumes itself. xen-front-pgdir-shbuf.c:164: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Calculate the number of grant references needed to share the buffer xen-front-pgdir-shbuf.c:176: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Calculate the number of grant references needed to share the buffer xen-front-pgdir-shbuf.c:194: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Unmap the buffer previously mapped with grant references xen-front-pgdir-shbuf.c:242: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Map the buffer with grant references provided by the backend. xen-front-pgdir-shbuf.c:324: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Fill page directory with grant references to the pages of the xen-front-pgdir-shbuf.c:354: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Fill page directory with grant references to the pages of the xen-front-pgdir-shbuf.c:393: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Grant references to the frontend's buffer pages. xen-front-pgdir-shbuf.c:422: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Grant all the references needed to share the buffer. xen-front-pgdir-shbuf.c:470: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Allocate all required structures to mange shared buffer. xen-front-pgdir-shbuf.c:510: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Allocate a new instance of a shared buffer. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Closes: lore.kernel.org/r/202311060203.yQrpPZhm-lkp@intel.com Acked-by: Juergen Gross <jgross@suse.com> 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 Link: https://lore.kernel.org/r/20231106055631.21520-1-rdunlap@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-13acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0Roger Pau Monne
The Processor capability bits notify ACPI of the OS capabilities, and so ACPI can adjust the return of other Processor methods taking the OS capabilities into account. When Linux is running as a Xen dom0, the hypervisor is the entity in charge of processor power management, and hence Xen needs to make sure the capabilities reported by _OSC/_PDC match the capabilities of the driver in Xen. Introduce a small helper to sanitize the buffer when running as Xen dom0. When Xen supports HWP, this serves as the equivalent of commit a21211672c9a ("ACPI / processor: Request native thermal interrupt handling via _OSC") to avoid SMM crashes. Xen will set bit ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the _OSC/_PDC call will apply it. [ jandryuk: Mention Xen HWP's need. Support _OSC & _PDC ] Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk <jandryuk@gmail.com> Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-13xen/events: avoid using info_for_irq() in xen_send_IPI_one()Juergen Gross
xen_send_IPI_one() is being used by cpuhp_report_idle_dead() after it calls rcu_report_dead(), meaning that any RCU usage by xen_send_IPI_one() is a bad idea. Unfortunately xen_send_IPI_one() is using notify_remote_via_irq() today, which is using irq_get_chip_data() via info_for_irq(). And irq_get_chip_data() in turn is using a maple-tree lookup requiring RCU. Avoid this problem by caching the ipi event channels in another percpu variable, allowing the use notify_remote_via_evtchn() in xen_send_IPI_one(). Fixes: 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management") Reported-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-11-02Merge tag 'mm-stable-2023-11-01-14-33' of ↵Linus Torvalds
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() ...
2023-11-02Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "Updates to the usual drivers (ufs, megaraid_sas, lpfc, target, ibmvfc, scsi_debug) plus the usual assorted minor fixes and updates. The major change this time around is a prep patch for rethreading of the driver reset handler API not to take a scsi_cmd structure which starts to reduce various drivers' dependence on scsi_cmd in error handling" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (132 commits) scsi: ufs: core: Leave space for '\0' in utf8 desc string scsi: ufs: core: Conversion to bool not necessary scsi: ufs: core: Fix race between force complete and ISR scsi: megaraid: Fix up debug message in megaraid_abort_and_reset() scsi: aic79xx: Fix up NULL command in ahd_done() scsi: message: fusion: Initialize return value in mptfc_bus_reset() scsi: mpt3sas: Fix loop logic scsi: snic: Remove useless code in snic_dr_clean_pending_req() scsi: core: Add comment to target_destroy in scsi_host_template scsi: core: Clean up scsi_dev_queue_ready() scsi: pmcraid: Add missing scsi_device_put() in pmcraid_eh_target_reset_handler() scsi: target: core: Fix kernel-doc comment scsi: pmcraid: Fix kernel-doc comment scsi: core: Handle depopulation and restoration in progress scsi: ufs: core: Add support for parsing OPP scsi: ufs: core: Add OPP support for scaling clocks and regulators scsi: ufs: dt-bindings: common: Add OPP table scsi: scsi_debug: Add param to control sdev's allow_restart scsi: scsi_debug: Add debugfs interface to fail target reset scsi: scsi_debug: Add new error injection type: Reset LUN failed ...
2023-11-01Merge tag 'sysctl-6.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "To help make the move of sysctls out of kernel/sysctl.c not incur a size penalty sysctl has been changed to allow us to not require the sentinel, the final empty element on the sysctl array. Joel Granados has been doing all this work. On the v6.6 kernel we got the major infrastructure changes required to support this. For v6.7-rc1 we have all arch/ and drivers/ modified to remove the sentinel. Both arch and driver changes have been on linux-next for a bit less than a month. It is worth re-iterating the value: - this helps reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array - the extra 64-byte penalty is no longer inncurred now when we move sysctls out from kernel/sysctl.c to their own files For v6.8-rc1 expect removal of all the sentinels and also then the unneeded check for procname == NULL. The last two patches are fixes recently merged by Krister Johansen which allow us again to use softlockup_panic early on boot. This used to work but the alias work broke it. This is useful for folks who want to detect softlockups super early rather than wait and spend money on cloud solutions with nothing but an eventual hung kernel. Although this hadn't gone through linux-next it's also a stable fix, so we might as well roll through the fixes now" * tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits) watchdog: move softlockup_panic back to early_param proc: sysctl: prevent aliased sysctls from getting passed to init intel drm: Remove now superfluous sentinel element from ctl_table array Drivers: hv: Remove now superfluous sentinel element from ctl_table array raid: Remove now superfluous sentinel element from ctl_table array fw loader: Remove the now superfluous sentinel element from ctl_table array sgi-xp: Remove the now superfluous sentinel element from ctl_table array vrf: Remove the now superfluous sentinel element from ctl_table array char-misc: Remove the now superfluous sentinel element from ctl_table array infiniband: Remove the now superfluous sentinel element from ctl_table array macintosh: Remove the now superfluous sentinel element from ctl_table array parport: Remove the now superfluous sentinel element from ctl_table array scsi: Remove now superfluous sentinel element from ctl_table array tty: Remove now superfluous sentinel element from ctl_table array xen: Remove now superfluous sentinel element from ctl_table array hpet: Remove now superfluous sentinel element from ctl_table array c-sky: Remove now superfluous sentinel element from ctl_talbe array powerpc: Remove now superfluous sentinel element from ctl_table arrays riscv: Remove now superfluous sentinel element from ctl_table array x86/vdso: Remove now superfluous sentinel element from ctl_table array ...
2023-11-01Merge tag 'for-linus-6.7-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - two small cleanup patches - a fix for PCI passthrough under Xen - a four patch series speeding up virtio under Xen with user space backends * tag 'for-linus-6.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-pciback: Consider INTx disabled when MSI/MSI-X is enabled xen: privcmd: Add support for ioeventfd xen: evtchn: Allow shared registration of IRQ handers xen: irqfd: Use _IOW instead of the internal _IOC() macro xen: Make struct privcmd_irqfd's layout architecture independent xen/xenbus: Add __counted_by for struct read_buffer and use struct_size() xenbus: fix error exit in xenbus_init()
2023-10-30Merge tag 'locking-core-2023-10-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Info Molnar: "Futex improvements: - Add the 'futex2' syscall ABI, which is an attempt to get away from the multiplex syscall and adds a little room for extentions, while lifting some limitations. - Fix futex PI recursive rt_mutex waiter state bug - Fix inter-process shared futexes on no-MMU systems - Use folios instead of pages Micro-optimizations of locking primitives: - Improve arch_spin_value_unlocked() on asm-generic ticket spinlock architectures, to improve lockref code generation - Improve the x86-32 lockref_get_not_zero() main loop by adding build-time CMPXCHG8B support detection for the relevant lockref code, and by better interfacing the CMPXCHG8B assembly code with the compiler - Introduce arch_sync_try_cmpxchg() on x86 to improve sync_try_cmpxchg() code generation. Convert some sync_cmpxchg() users to sync_try_cmpxchg(). - Micro-optimize rcuref_put_slowpath() Locking debuggability improvements: - Improve CONFIG_DEBUG_RT_MUTEXES=y to have a fast-path as well - Enforce atomicity of sched_submit_work(), which is de-facto atomic but was un-enforced previously. - Extend <linux/cleanup.h>'s no_free_ptr() with __must_check semantics - Fix ww_mutex self-tests - Clean up const-propagation in <linux/seqlock.h> and simplify the API-instantiation macros a bit RT locking improvements: - Provide the rt_mutex_*_schedule() primitives/helpers and use them in the rtmutex code to avoid recursion vs. rtlock on the PI state. - Add nested blocking lockdep asserts to rt_mutex_lock(), rtlock_lock() and rwbase_read_lock() .. plus misc fixes & cleanups" * tag 'locking-core-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits) futex: Don't include process MM in futex key on no-MMU locking/seqlock: Fix grammar in comment alpha: Fix up new futex syscall numbers locking/seqlock: Propagate 'const' pointers within read-only methods, remove forced type casts locking/lockdep: Fix string sizing bug that triggers a format-truncation compiler-warning locking/seqlock: Change __seqprop() to return the function pointer locking/seqlock: Simplify SEQCOUNT_LOCKNAME() locking/atomics: Use atomic_try_cmpxchg_release() to micro-optimize rcuref_put_slowpath() locking/atomic, xen: Use sync_try_cmpxchg() instead of sync_cmpxchg() locking/atomic/x86: Introduce arch_sync_try_cmpxchg() locking/atomic: Add generic support for sync_try_cmpxchg() and its fallback locking/seqlock: Fix typo in comment futex/requeue: Remove unnecessary ‘NULL’ initialization from futex_proxy_trylock_atomic() locking/local, arch: Rewrite local_add_unless() as a static inline function locking/debug: Fix debugfs API return value checks to use IS_ERR() locking/ww_mutex/test: Make sure we bail out instead of livelock locking/ww_mutex/test: Fix potential workqueue corruption locking/ww_mutex/test: Use prng instead of rng to avoid hangs at bootup futex: Add sys_futex_requeue() futex: Add flags2 argument to futex_requeue() ...
2023-10-16xen-pciback: Consider INTx disabled when MSI/MSI-X is enabledMarek Marczykowski-Górecki
Linux enables MSI-X before disabling INTx, but keeps MSI-X masked until the table is filled. Then it disables INTx just before clearing MASKALL bit. Currently this approach is rejected by xen-pciback. According to the PCIe spec, device cannot use INTx when MSI/MSI-X is enabled (in other words: enabling MSI/MSI-X implicitly disables INTx). Change the logic to consider INTx disabled if MSI/MSI-X is enabled. This applies to three places: - checking currently enabled interrupts type, - transition to MSI/MSI-X - where INTx would be implicitly disabled, - clearing INTx disable bit - which can be allowed even if MSI/MSI-X is enabled, as device should consider INTx disabled anyway in that case Fixes: 5e29500eba2a ("xen-pciback: Allow setting PCI_MSIX_FLAGS_MASKALL too") Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Acked-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20231016131348.1734721-1-marmarek@invisiblethingslab.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-16xen: privcmd: Add support for ioeventfdViresh Kumar
Virtio guests send VIRTIO_MMIO_QUEUE_NOTIFY notification when they need to notify the backend of an update to the status of the virtqueue. The backend or another entity, polls the MMIO address for updates to know when the notification is sent. It works well if the backend does this polling by itself. But as we move towards generic backend implementations, we end up implementing this in a separate user-space program. Generally, the Virtio backends are implemented to work with the Eventfd based mechanism. In order to make such backends work with Xen, another software layer needs to do the polling and send an event via eventfd to the backend once the notification from guest is received. This results in an extra context switch. This is not a new problem in Linux though. It is present with other hypervisors like KVM, etc. as well. The generic solution implemented in the kernel for them is to provide an IOCTL call to pass the address to poll and eventfd, which lets the kernel take care of polling and raise an event on the eventfd, instead of handling this in user space (which involves an extra context switch). This patch adds similar support for xen. Inspired by existing implementations for KVM, etc.. This also copies ioreq.h header file (only struct ioreq and related macros) from Xen's source tree (Top commit 5d84f07fe6bf ("xen/pci: drop remaining uses of bool_t")). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/b20d83efba6453037d0c099912813c79c81f7714.1697439990.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-16xen: evtchn: Allow shared registration of IRQ handersViresh Kumar
Currently the handling of events is supported either in the kernel or userspace, but not both. In order to support fast delivery of interrupts from the guest to the backend, we need to handle the Queue notify part of Virtio protocol in kernel and the rest in userspace. Update the interrupt handler registration flag to IRQF_SHARED for event channels, which would allow multiple entities to bind their interrupt handler for the same event channel port. Also increment the reference count of irq_info when multiple entities try to bind event channel to irqchip, so the unbinding happens only after all the users are gone. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/99b1edfd3147c6b5d22a5139dab5861e767dc34a.1697439990.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-16xen: Make struct privcmd_irqfd's layout architecture independentViresh Kumar
Using indirect pointers in an ioctl command argument means that the layout is architecture specific, in particular we can't use the same one from 32-bit compat tasks. The general recommendation is to have __u64 members and use u64_to_user_ptr() to access it from the kernel if we are unable to avoid the pointers altogether. Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") Reported-by: Arnd Bergmann <arnd@kernel.org> Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/ Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/a4ef0d4a68fc858b34a81fd3f9877d9b6898eb77.1697439990.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-16xen/xenbus: Add __counted_by for struct read_buffer and use struct_size()Gustavo A. R. Silva
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 Gross
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>
2023-10-13scsi: target: Have drivers report if they support direct submissionsMike Christie
In some cases, like with multiple LUN targets or where the target has to respond to transport level requests from the receiving context it can be better to defer cmd submission to a helper thread. If the backend driver blocks on something like request/tag allocation it can block the entire target submission path and other LUs and transport IO on that session. In other cases like single LUN targets with storage that can support all the commands that the target can queue, then it's best to submit the cmd to the backend from the target's cmd receiving context. Subsequent commits will allow the user to config what they prefer, but drivers like loop can't directly submit because they can be called from a context that can't sleep. And, drivers like vhost-scsi can support direct submission, but need to keep their default behavior of deferring execution to avoid possible regressions where the backend can block. Make the drivers tell LIO core if they support direct submissions and their current default, so we can prevent users from misconfiguring the system and initialize devices correctly. Signed-off-by: Mike Christie <michael.christie@oracle.com> Link: https://lore.kernel.org/r/20230928020907.5730-2-michael.christie@oracle.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-10-11xen: Remove now superfluous sentinel element from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel from balloon_table Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-10-09locking/atomic, xen: Use sync_try_cmpxchg() instead of sync_cmpxchg()Uros Bizjak
Use sync_try_cmpxchg() instead of sync_cmpxchg(*ptr, old, new) == old in clear_masked_cond(), clear_linked() and gnttab_end_foreign_access_ref_v1(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg), improving the cmpxchg loop in gnttab_end_foreign_access_ref_v1() from: 174: eb 0e jmp 184 <...> 176: 89 d0 mov %edx,%eax 178: f0 66 0f b1 31 lock cmpxchg %si,(%rcx) 17d: 66 39 c2 cmp %ax,%dx 180: 74 11 je 193 <...> 182: 89 c2 mov %eax,%edx 184: 89 d6 mov %edx,%esi 186: 66 83 e6 18 and $0x18,%si 18a: 74 ea je 176 <...> to: 614: 89 c1 mov %eax,%ecx 616: 66 83 e1 18 and $0x18,%cx 61a: 75 11 jne 62d <...> 61c: f0 66 0f b1 0a lock cmpxchg %cx,(%rdx) 621: 75 f1 jne 614 <...> No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org
2023-10-09xen/events: replace evtchn_rwlock with RCUJuergen Gross
In unprivileged Xen guests event handling can cause a deadlock with Xen console handling. The evtchn_rwlock and the hvc_lock are taken in opposite sequence in __hvc_poll() and in Xen console IRQ handling. Normally this is no problem, as the evtchn_rwlock is taken as a reader in both paths, but as soon as an event channel is being closed, the lock will be taken as a writer, which will cause read_lock() to block: CPU0 CPU1 CPU2 (IRQ handling) (__hvc_poll()) (closing event channel) read_lock(evtchn_rwlock) spin_lock(hvc_lock) write_lock(evtchn_rwlock) [blocks] spin_lock(hvc_lock) [blocks] read_lock(evtchn_rwlock) [blocks due to writer waiting, and not in_interrupt()] This issue can be avoided by replacing evtchn_rwlock with RCU in xen_free_irq(). Note that RCU is used only to delay freeing of the irq_info memory. There is no RCU based dereferencing or replacement of pointers involved. In order to avoid potential races between removing the irq_info reference and handling of interrupts, set the irq_info pointer to NULL only when freeing its memory. The IRQ itself must be freed at that time, too, as otherwise the same IRQ number could be allocated again before handling of the old instance would have been finished. This is XSA-441 / CVE-2023-34324. Fixes: 54c9de89895e ("xen/events: add a new "late EOI" evtchn framework") Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-04xenbus/backend: dynamically allocate the xen-backend shrinkerQi Zheng
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>
2023-09-19xen: simplify evtchn_do_upcall() call mazeJuergen Gross
There are several functions involved for performing the functionality of evtchn_do_upcall(): - __xen_evtchn_do_upcall() doing the real work - xen_hvm_evtchn_do_upcall() just being a wrapper for __xen_evtchn_do_upcall(), exposed for external callers - xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but without any user Simplify this maze by: - removing the unused xen_evtchn_do_upcall() - removing xen_hvm_evtchn_do_upcall() as the only left caller of __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to xen_evtchn_do_upcall() Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-29Merge tag 'dma-mapping-6.6-2023-08-29' of ↵Linus Torvalds
git://git.infradead.org/users/hch/dma-mapping Pull dma-maping updates from Christoph Hellwig: - allow dynamic sizing of the swiotlb buffer, to cater for secure virtualization workloads that require all I/O to be bounce buffered (Petr Tesarik) - move a declaration to a header (Arnd Bergmann) - check for memory region overlap in dma-contiguous (Binglei Wang) - remove the somewhat dangerous runtime swiotlb-xen enablement and unexport is_swiotlb_active (Christoph Hellwig, Juergen Gross) - per-node CMA improvements (Yajun Deng) * tag 'dma-mapping-6.6-2023-08-29' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: optimize get_max_slots() swiotlb: move slot allocation explanation comment where it belongs swiotlb: search the software IO TLB only if the device makes use of it swiotlb: allocate a new memory pool when existing pools are full swiotlb: determine potential physical address limit swiotlb: if swiotlb is full, fall back to a transient memory pool swiotlb: add a flag whether SWIOTLB is allowed to grow swiotlb: separate memory pool data from other allocator data swiotlb: add documentation and rename swiotlb_do_find_slots() swiotlb: make io_tlb_default_mem local to swiotlb.c swiotlb: bail out of swiotlb_init_late() if swiotlb is already allocated dma-contiguous: check for memory region overlap dma-contiguous: support numa CMA for specified node dma-contiguous: support per-numa CMA for all architectures dma-mapping: move arch_dma_set_mask() declaration to header swiotlb: unexport is_swiotlb_active x86: always initialize xen-swiotlb when xen-pcifront is enabling xen/pci: add flag for PCI passthrough being possible
2023-08-22xen: privcmd: Add support for irqfdViresh Kumar
Xen provides support for injecting interrupts to the guests via the HYPERVISOR_dm_op() hypercall. The same is used by the Virtio based device backend implementations, in an inefficient manner currently. Generally, the Virtio backends are implemented to work with the Eventfd based mechanism. In order to make such backends work with Xen, another software layer needs to poll the Eventfds and raise an interrupt to the guest using the Xen based mechanism. This results in an extra context switch. This is not a new problem in Linux though. It is present with other hypervisors like KVM, etc. as well. The generic solution implemented in the kernel for them is to provide an IOCTL call to pass the interrupt details and eventfd, which lets the kernel take care of polling the eventfd and raising of the interrupt, instead of handling this in user space (which involves an extra context switch). This patch adds support to inject a specific interrupt to guest using the eventfd mechanism, by preventing the extra context switch. Inspired by existing implementations for KVM, etc.. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/8e724ac1f50c2bc1eb8da9b3ff6166f1372570aa.1692697321.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-22xen/xenbus: Avoid a lockdep warning when adding a watchPetr Pavlu
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: Fix one kernel-doc commentYang Li
Use colon to separate parameter name from their specific meaning. silence the warning: drivers/xen/grant-table.c:1051: warning: Function parameter or member 'nr_pages' not described in 'gnttab_free_pages' Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=6030 Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Acked-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20230731030037.123946-1-yang.lee@linux.alibaba.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21xen: xenbus: Use helper function IS_ERR_OR_NULL()Li Zetao
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>
2023-08-21xen: Switch to use kmemdup() helperRuan Jinjie
Use kmemdup() helper instead of open-coding to simplify the code. Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Chen Jiahao <chenjiahao16@huawei.com> Link: https://lore.kernel.org/r/20230815092434.1206386-1-ruanjinjie@huawei.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21xen-pciback: Remove unused function declarationsYue Haibing
Commit a92336a1176b ("xen/pciback: Drop two backends, squash and cleanup some code.") declared but never implemented these functions. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20230808150912.43416-1-yuehaibing@huawei.com Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-01swiotlb: make io_tlb_default_mem local to swiotlb.cPetr Tesarik
SWIOTLB implementation details should not be exposed to the rest of the kernel. This will allow to make changes to the implementation without modifying non-swiotlb code. To avoid breaking existing users, provide helper functions for the few required fields. As a bonus, using a helper function to initialize struct device allows to get rid of an #ifdef in driver core. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-27xen: speed up grant-table reclaimDemi Marie Obenour
When a grant entry is still in use by the remote domain, Linux must put it on a deferred list. Normally, this list is very short, because the PV network and block protocols expect the backend to unmap the grant first. However, Qubes OS's GUI protocol is subject to the constraints of the X Window System, and as such winds up with the frontend unmapping the window first. As a result, the list can grow very large, resulting in a massive memory leak and eventual VM freeze. To partially solve this problem, make the number of entries that the VM will attempt to free at each iteration tunable. The default is still 10, but it can be overridden via a module parameter. This is Cc: stable because (when combined with appropriate userspace changes) it fixes a severe performance and stability problem for Qubes OS users. Cc: stable@vger.kernel.org Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20230726165354.1252-1-demi@invisiblethingslab.com Signed-off-by: Juergen Gross <jgross@suse.com>
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