lwn.git/drivers/xen/privcmd.c, branch docs-5.13

xen/privcmd: allow fetching resource sizes

2021-01-13T11:31:17+00:00

Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and addr = 0 in order to fetch the size of a specific resource. Add a shortcut to the default map resource path, since fetching the size requires no address to be passed in, and thus no VMA to setup. This is missing from the initial implementation, and causes issues when mapping resources that don't have fixed or known sizes. Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Tested-by: Andrew Cooper Cc: stable@vger.kernel.org # >= 4.18 Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com Signed-off-by: Juergen Gross

Merge tag 'for-linus-5.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2020-09-06T16:59:27+00:00

Pull xen updates from Juergen Gross: "A small series for fixing a problem with Xen PVH guests when running as backends (e.g. as dom0). Mapping other guests' memory is now working via ZONE_DEVICE, thus not requiring to abuse the memory hotplug functionality for that purpose" * tag 'for-linus-5.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: add helpers to allocate unpopulated memory memremap: rename MEMORY_DEVICE_DEVDAX to MEMORY_DEVICE_GENERIC xen/balloon: add header guard

xen: add helpers to allocate unpopulated memory

2020-09-04T08:00:01+00:00

To be used in order to create foreign mappings. This is based on the ZONE_DEVICE facility which is used by persistent memory devices in order to create struct pages and kernel virtual mappings for the IOMEM areas of such devices. Note that on kernels without support for ZONE_DEVICE Xen will fallback to use ballooned pages in order to create foreign mappings. The newly added helpers use the same parameters as the existing {alloc/free}_xenballooned_pages functions, which allows for in-place replacement of the callers. Once a memory region has been added to be used as scratch mapping space it will no longer be released, and pages returned are kept in a linked list. This allows to have a buffer of pages and prevents resorting to frequent additions and removals of regions. If enabled (because ZONE_DEVICE is supported) the usage of the new functionality untangles Xen balloon and RAM hotplug from the usage of unpopulated physical memory ranges to map foreign pages, which is the correct thing to do in order to avoid mappings of foreign pages depend on memory hotplug. Note the driver is currently not enabled on Arm platforms because it would interfere with the identity mapping required on some platforms. Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20200901083326.21264-4-roger.pau@citrix.com Signed-off-by: Juergen Gross

Merge branch 'akpm' (patches from Andrew)

2020-08-07T18:39:33+00:00

Merge misc updates from Andrew Morton: - a few MM hotfixes - kthread, tools, scripts, ntfs and ocfs2 - some of MM Subsystems affected by this patch series: kthread, tools, scripts, ntfs, ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore, sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan). * emailed patches from Andrew Morton : (162 commits) mm: vmscan: consistent update to pgrefill mm/vmscan.c: fix typo khugepaged: khugepaged_test_exit() check mmget_still_valid() khugepaged: retract_page_tables() remember to test exit khugepaged: collapse_pte_mapped_thp() protect the pmd lock khugepaged: collapse_pte_mapped_thp() flush the right range mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible mm: thp: replace HTTP links with HTTPS ones mm/page_alloc: fix memalloc_nocma_{save/restore} APIs mm/page_alloc.c: skip setting nodemask when we are in interrupt mm/page_alloc: fallbacks at most has 3 elements mm/page_alloc: silence a KASAN false positive mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask() mm/page_alloc.c: simplify pageblock bitmap access mm/page_alloc.c: extract the common part in pfn_to_bitidx() mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits mm/shuffle: remove dynamic reconfiguration mm/memory_hotplug: document why shuffle_zone() is relevant mm/page_alloc: remove nr_free_pagecache_pages() mm: remove vm_total_pages ...

mm: remove unneeded includes of

2020-08-07T18:33:26+00:00

Patch series "mm: cleanup usage of " Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in and enable use of the generic functions where appropriate. In addition, functions declared and defined in headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the included all over the place. The first patch in this series removes unneeded includes of In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in and do not require that header. As for the other header files that used to include , it is possible to move that include into the .c file that actually uses symbols from and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Reviewed-by: Pekka Enberg Acked-by: Geert Uytterhoeven [m68k] Cc: Abdul Haleem Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Joerg Roedel Cc: Max Filippov Cc: Peter Zijlstra Cc: Satheesh Rajendran Cc: Stafford Horne Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Joerg Roedel Cc: Matthew Wilcox Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds

xen/privcmd: Convert get_user_pages() to pin_user_pages()

2020-08-03T05:43:16+00:00

In 2019, we introduced pin_user_pages*() and now we are converting get_user_pages*() to the new API as appropriate. [1] & [2] could be referred for more information. This is case 5 as per document [1]. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by: Souptick Joarder Reviewed-by: Juergen Gross Reviewed-by: Paul Durrant Cc: John Hubbard Cc: Boris Ostrovsky Cc: Paul Durrant Link: https://lore.kernel.org/r/1594525195-28345-4-git-send-email-jrdr.linux@gmail.com Signed-off-by: Juergen Gross

xen/privcmd: Mark pages as dirty

2020-08-03T05:42:18+00:00

pages need to be marked as dirty before unpinned it in unlock_pages() which was oversight. This is fixed now. Signed-off-by: Souptick Joarder Suggested-by: John Hubbard Reviewed-by: Juergen Gross Reviewed-by: Paul Durrant Cc: John Hubbard Cc: Boris Ostrovsky Cc: Paul Durrant Link: https://lore.kernel.org/r/1594525195-28345-3-git-send-email-jrdr.linux@gmail.com Signed-off-by: Juergen Gross

xen/privcmd: Corrected error handling path

2020-08-03T05:41:25+00:00

Previously, if lock_pages() end up partially mapping pages, it used to return -ERRNO due to which unlock_pages() have to go through each pages[i] till *nr_pages* to validate them. This can be avoided by passing correct number of partially mapped pages & -ERRNO separately, while returning from lock_pages() due to error. With this fix unlock_pages() doesn't need to validate pages[i] till *nr_pages* for error scenario and few condition checks can be ignored. Signed-off-by: Souptick Joarder Reviewed-by: Juergen Gross Reviewed-by: Paul Durrant Cc: John Hubbard Cc: Boris Ostrovsky Cc: Paul Durrant Link: https://lore.kernel.org/r/1594525195-28345-2-git-send-email-jrdr.linux@gmail.com Signed-off-by: Juergen Gross

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14+00:00

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include in the files that include . The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include ") ; do sed -i -e '/include / d' $f done Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Rapoport Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds