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path: root/drivers/xen/gntdev.c
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2021-09-20Xen/gntdev: don't ignore kernel unmapping errorJan Beulich1-0/+8
While working on XSA-361 and its follow-ups, I failed to spot another place where the kernel mapping part of an operation was not treated the same as the user space part. Detect and propagate errors and add a 2nd pr_debug(). Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/c2513395-74dc-aea3-9192-fd265aa44e35@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2021-08-30xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guestsJuergen Gross1-34/+2
XENFEAT_gnttab_map_avail_bits is always set in Xen 4.0 and newer. Remove coding assuming it might be zero. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210730071804.4302-4-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2021-05-10xen/gntdev: fix gntdev_mmap() error exit pathJuergen Gross1-1/+3
Commit d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") introduced an error in gntdev_mmap(): in case the call of mmu_interval_notifier_insert_locked() fails the exit path should not call mmu_interval_notifier_remove(), as this might result in NULL dereferences. One reason for failure is e.g. a signal pending for the running process. Fixes: d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") Cc: stable@vger.kernel.org Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Luca Fancellu <luca.fancellu@arm.com> Link: https://lore.kernel.org/r/20210423054038.26696-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
2021-03-11Xen/gntdev: don't needlessly use kvcalloc()Jan Beulich1-7/+12
Requesting zeroed memory when all of it will be overwritten subsequently by all ones is a waste of processing bandwidth. In fact, rather than recording zeroed ->grants[], fill that array too with more appropriate "invalid" indicators. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/9a726be2-4893-8ffe-0ef1-b70dd1c229b1@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-03-11Xen/gnttab: introduce common INVALID_GRANT_{HANDLE,REF}Jan Beulich1-11/+13
It's not helpful if every driver has to cook its own. Generalize xenbus'es INVALID_GRANT_HANDLE and pcifront's INVALID_GRANT_REF (which shouldn't have expanded to zero to begin with). Use the constants in p2m.c and gntdev.c right away, and update field types where necessary so they would match with the constants' types (albeit without touching struct ioctl_gntdev_grant_ref's ref field, as that's part of the public interface of the kernel and would require introducing a dependency on Xen's grant_table.h public header). Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/db7c38a5-0d75-d5d1-19de-e5fe9f0b9c48@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-03-11Xen/gntdev: don't needlessly allocate k{,un}map_ops[]Jan Beulich1-9/+14
They're needed only in the not-auto-translate (i.e. PV) case; there's no point in allocating memory that's never going to get accessed. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/180d50cb-5531-8952-4bf0-d65c554638ed@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-02-15Xen/gntdev: correct error checking in gntdev_map_grant_pages()Jan Beulich1-8/+9
Failure of the kernel part of the mapping operation should also be indicated as an error to the caller, or else it may assume the respective kernel VA is okay to access. Furthermore gnttab_map_refs() failing still requires recording successfully mapped handles, so they can be unmapped subsequently. This in turn requires there to be a way to tell full hypercall failure from partial success - preset map_op status fields such that they won't "happen" to look as if the operation succeeded. Also again use GNTST_okay instead of implying its value (zero). This is part of XSA-361. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2021-02-15Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()Jan Beulich1-11/+13
We may not skip setting the field in the unmap structure when GNTMAP_device_map is in use - such an unmap would fail to release the respective resources (a page ref in the hypervisor). Otoh the field doesn't need setting at all when GNTMAP_device_map is not in use. To record the value for unmapping, we also better don't use our local p2m: In particular after a subsequent change it may not have got updated for all the batch elements. Instead it can simply be taken from the respective map's results. We can additionally avoid playing this game altogether for the kernel part of the mappings in (x86) PV mode. This is part of XSA-361. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
2020-10-05xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()Souptick Joarder1-8/+2
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 <jrdr.linux@gmail.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: David Vrabel <david.vrabel@citrix.com> Link: https://lore.kernel.org/r/1599375114-32360-2-git-send-email-jrdr.linux@gmail.com Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2020-10-05xen/gntdev.c: Mark pages as dirtySouptick Joarder1-5/+12
There seems to be a bug in the original code when gntdev_get_page() is called with writeable=true then the page needs to be marked dirty before being put. To address this, a bool writeable is added in gnt_dev_copy_batch, set it in gntdev_grant_copy_seg() (and drop `writeable` argument to gntdev_get_page()) and then, based on batch->writeable, use set_page_dirty_lock(). Fixes: a4cdb556cae0 (xen/gntdev: add ioctl for grant copy) Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1599375114-32360-1-git-send-email-jrdr.linux@gmail.com Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-1/+1
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse1-2/+2
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 <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07xen: Use evtchn_type_t as a type for event channelsYan Yankovskyi1-1/+1
Make event channel functions pass event channel port using evtchn_port_t type. It eliminates signed <-> unsigned conversion. Signed-off-by: Yan Yankovskyi <yyankovskyi@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20200323152343.GA28422@kbp1-lhp-F74019 Signed-off-by: Juergen Gross <jgross@suse.com>
2020-01-28xen/gntdev: Do not use mm notifiers with autotranslating guestsBoris Ostrovsky1-12/+12
Commit d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert") missed a test for use_ptemod when calling mmu_interval_read_begin(). Fix that. Fixes: d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert") CC: stable@vger.kernel.org # 5.5 Reported-by: Ilpo Järvinen <ilpo.jarvinen@cs.helsinki.fi> Tested-by: Ilpo Järvinen <ilpo.jarvinen@cs.helsinki.fi> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Juergen Gross <jgross@suse.com>
2019-12-02xen/gntdev: switch from kcalloc() to kvcalloc()Juergen Gross1-15/+16
With sufficient many pages to map gntdev can reach order 9 allocation sizes. As there is no need to have physically contiguous buffers switch to kvcalloc() in order to avoid failing allocations. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-02xen/gntdev: replace global limit of mapped pages by limit per callJuergen Gross1-17/+7
Today there is a global limit of pages mapped via /dev/xen/gntdev set to 1 million pages per default. There is no reason why that limit is existing, as total number of grant mappings is limited by the hypervisor anyway and preferring kernel mappings over userspace ones doesn't make sense. It should be noted that the gntdev device is usable by root only. Additionally checking of that limit is fragile, as the number of pages to map via one call is specified in a 32-bit unsigned variable which isn't tested to stay within reasonable limits (the only test is the value to be <= zero, which basically excludes only calls without any mapping requested). So trying to map e.g. 0xffff0000 pages while already nearly 1000000 pages are mapped will effectively lower the global number of mapped pages such that a parallel call mapping a reasonable amount of pages can succeed in spite of the global limit being violated. So drop the global limit and introduce per call limit instead. This per call limit (default: 65536 grant mappings) protects against allocating insane large arrays in the kernel for doing a hypercall which will fail anyway in case a user is e.g. trying to map billions of pages. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-02xen/gntdev: remove redundant non-zero check on retColin Ian King1-7/+2
The non-zero check on ret is always going to be false because ret was initialized as zero and the only place it is set to non-zero contains a return path before the non-zero check. Hence the check is redundant and can be removed. [ jgross@suse.com: limit scope of ret ] Addresses-Coverity: ("Logically dead code") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-11-24xen/gntdev: use mmu_interval_notifier_insertJason Gunthorpe1-131/+48
gntdev simply wants to monitor a specific VMA for any notifier events, this can be done straightforwardly using mmu_interval_notifier_insert() over the VMA's VA range. The notifier should be attached until the original VMA is destroyed. It is unclear if any of this is even sane, but at least a lot of duplicate code is removed. Link: https://lore.kernel.org/r/20191112202231.3856-15-jgg@ziepe.ca Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-10xen: Stop abusing DT of_dma_configure APIRob Herring1-11/+2
As the removed comments say, these aren't DT based devices. of_dma_configure() is going to stop allowing a NULL DT node and calling it will no longer work. The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64: default to the direct mapping in get_arch_dma_ops"). Direct mapping is now the default rather than dma_dummy_ops. According to Stefano and Oleksandr, the only other part needed is setting the DMA masks and there's no reason to restrict the masks to 32-bits. So set the masks to 64 bits. Cc: Robin Murphy <robin.murphy@arm.com> Cc: Julien Grall <julien.grall@arm.com> Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: xen-devel@lists.xenproject.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-07-31xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero()Souptick Joarder1-1/+1
'commit df9bde015a72 ("xen/gntdev.c: convert to use vm_map_pages()")' breaks gntdev driver. If vma->vm_pgoff > 0, vm_map_pages() will: - use map->pages starting at vma->vm_pgoff instead of 0 - verify map->count against vma_pages()+vma->vm_pgoff instead of just vma_pages(). In practice, this breaks using a single gntdev FD for mapping multiple grants. relevant strace output: [pid 857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0 [pid 857] mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 7, 0) = 0x777f1211b000 [pid 857] ioctl(7, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, 0x7ffd3407b710) = 0 [pid 857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0 [pid 857] mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 7, 0x1000) = -1 ENXIO (No such device or address) details here: https://github.com/QubesOS/qubes-issues/issues/5199 The reason is -> ( copying Marek's word from discussion) vma->vm_pgoff is used as index passed to gntdev_find_map_index. It's basically using this parameter for "which grant reference to map". map struct returned by gntdev_find_map_index() describes just the pages to be mapped. Specifically map->pages[0] should be mapped at vma->vm_start, not vma->vm_start+vma->vm_pgoff*PAGE_SIZE. When trying to map grant with index (aka vma->vm_pgoff) > 1, __vm_map_pages() will refuse to map it because it will expect map->count to be at least vma_pages(vma)+vma->vm_pgoff, while it is exactly vma_pages(vma). Converting vm_map_pages() to use vm_map_pages_zero() will fix the problem. Marek has tested and confirmed the same. Cc: stable@vger.kernel.org # v5.2+ Fixes: df9bde015a72 ("xen/gntdev.c: convert to use vm_map_pages()") Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-07-12mm/pgtable: drop pgtable_t variable from pte_fn_t functionsAnshuman Khandual1-4/+2
Drop the pgtable_t variable from all implementation for pte_fn_t as none of them use it. apply_to_pte_range() should stop computing it as well. Should help us save some cycles. Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Matthew Wilcox <willy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <jglisse@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14xen/gntdev.c: convert to use vm_map_pages()Souptick Joarder1-7/+4
Convert to use vm_map_pages() to map range of kernel memory to user vma. map->count is passed to vm_map_pages() and internal API verify map->count against count ( count = vma_pages(vma)) for page array boundary overrun condition. Link: http://lkml.kernel.org/r/88e56e82d2db98705c2d842e9c9806c00b366d67.1552921225.git.jrdr.linux@gmail.com Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Airlie <airlied@linux.ie> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: Pawel Osciak <pawel@osciak.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Sandy Huang <hjc@rock-chips.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thierry Reding <treding@nvidia.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/mmu_notifier: convert user range->blockable to helper functionJérôme Glisse1-3/+3
Use the mmu_notifier_range_blockable() helper function instead of directly dereferencing the range->blockable field. This is done to make it easier to change the mmu_notifier range field. This patch is the outcome of the following coccinelle patch: %<------------------------------------------------------------------- @@ identifier I1, FN; @@ FN(..., struct mmu_notifier_range *I1, ...) { <... -I1->blockable +mmu_notifier_range_blockable(I1) ...> } ------------------------------------------------------------------->% spatch --in-place --sp-file blockable.spatch --dir . Link: http://lkml.kernel.org/r/20190326164747.24405-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Christian König <christian.koenig@amd.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-1/+1
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-18xen/gntdev: Do not destroy context while dma-bufs are in useOleksandr Andrushchenko1-1/+1
If there are exported DMA buffers which are still in use and grant device is closed by either normal user-space close or by a signal this leads to the grant device context to be destroyed, thus making it not possible to correctly destroy those exported buffers when they are returned back to gntdev and makes the module crash: [ 339.617540] [<ffff00000854c0d8>] dmabuf_exp_ops_release+0x40/0xa8 [ 339.617560] [<ffff00000867a6e8>] dma_buf_release+0x60/0x190 [ 339.617577] [<ffff0000082211f0>] __fput+0x88/0x1d0 [ 339.617589] [<ffff000008221394>] ____fput+0xc/0x18 [ 339.617607] [<ffff0000080ed4e4>] task_work_run+0x9c/0xc0 [ 339.617622] [<ffff000008089714>] do_notify_resume+0xfc/0x108 Fix this by referencing gntdev on each DMA buffer export and unreferencing on buffer release. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2018-12-28mm/mmu_notifier: use structure for invalidate_range_start/end callbackJérôme Glisse1-6/+6
Patch series "mmu notifier contextual informations", v2. This patchset adds contextual information, why an invalidation is happening, to mmu notifier callback. This is necessary for user of mmu notifier that wish to maintains their own data structure without having to add new fields to struct vm_area_struct (vma). For instance device can have they own page table that mirror the process address space. When a vma is unmap (munmap() syscall) the device driver can free the device page table for the range. Today we do not have any information on why a mmu notifier call back is happening and thus device driver have to assume that it is always an munmap(). This is inefficient at it means that it needs to re-allocate device page table on next page fault and rebuild the whole device driver data structure for the range. Other use case beside munmap() also exist, for instance it is pointless for device driver to invalidate the device page table when the invalidation is for the soft dirtyness tracking. Or device driver can optimize away mprotect() that change the page table permission access for the range. This patchset enables all this optimizations for device drivers. I do not include any of those in this series but another patchset I am posting will leverage this. The patchset is pretty simple from a code point of view. The first two patches consolidate all mmu notifier arguments into a struct so that it is easier to add/change arguments. The last patch adds the contextual information (munmap, protection, soft dirty, clear, ...). This patch (of 3): To avoid having to change many callback definition everytime we want to add a parameter use a structure to group all parameters for the mmu_notifier invalidate_range_start/end callback. No functional changes with this patch. [akpm@linux-foundation.org: fix drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c kerneldoc] Link: http://lkml.kernel.org/r/20181205053628.3210-2-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Jason Gunthorpe <jgg@mellanox.com> [infiniband] Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-14xen/gntdev: fix up blockable calls to mn_invl_range_startMichal Hocko1-11/+15
Patch series "mmu_notifiers follow ups". Tetsuo has noticed some fallouts from 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers"). One of them has been fixed and picked up by AMD/DRM maintainer [1]. XEN issue is fixed by patch 1. I have also clarified expectations about blockable semantic of invalidate_range_end. Finally the last patch removes MMU_INVALIDATE_DOES_NOT_BLOCK which is no longer used nor needed. [1] http://lkml.kernel.org/r/20180824135257.GU29735@dhcp22.suse.cz This patch (of 3): 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers") has introduced blockable parameter to all mmu_notifiers and the notifier has to back off when called in !blockable case and it could block down the road. The above commit implemented that for mn_invl_range_start but both in_range checks are done unconditionally regardless of the blockable mode and as such they would fail all the time for regular calls. Fix this by checking blockable parameter as well. Once we are there we can remove the stale TODO. The lock has to be sleepable because we wait for completion down in gnttab_unmap_refs_sync. Link: http://lkml.kernel.org/r/20180827112623.8992-2-mhocko@kernel.org Fixes: 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers") Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-08-22mm, oom: distinguish blockable mode for mmu notifiersMichal Hocko1-9/+35
There are several blockable mmu notifiers which might sleep in mmu_notifier_invalidate_range_start and that is a problem for the oom_reaper because it needs to guarantee a forward progress so it cannot depend on any sleepable locks. Currently we simply back off and mark an oom victim with blockable mmu notifiers as done after a short sleep. That can result in selecting a new oom victim prematurely because the previous one still hasn't torn its memory down yet. We can do much better though. Even if mmu notifiers use sleepable locks there is no reason to automatically assume those locks are held. Moreover majority of notifiers only care about a portion of the address space and there is absolutely zero reason to fail when we are unmapping an unrelated range. Many notifiers do really block and wait for HW which is harder to handle and we have to bail out though. This patch handles the low hanging fruit. __mmu_notifier_invalidate_range_start gets a blockable flag and callbacks are not allowed to sleep if the flag is set to false. This is achieved by using trylock instead of the sleepable lock for most callbacks and continue as long as we do not block down the call chain. I think we can improve that even further because there is a common pattern to do a range lookup first and then do something about that. The first part can be done without a sleeping lock in most cases AFAICS. The oom_reaper end then simply retries if there is at least one notifier which couldn't make any progress in !blockable mode. A retry loop is already implemented to wait for the mmap_sem and this is basically the same thing. The simplest way for driver developers to test this code path is to wrap userspace code which uses these notifiers into a memcg and set the hard limit to hit the oom. This can be done e.g. after the test faults in all the mmu notifier managed memory and set the hard limit to something really small. Then we are looking for a proper process tear down. [akpm@linux-foundation.org: coding style fixes] [akpm@linux-foundation.org: minor code simplification] Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp Reported-by: David Rientjes <rientjes@google.com> Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> Cc: Dennis Dalessandro <dennis.dalessandro@intel.com> Cc: Sudeep Dutt <sudeep.dutt@intel.com> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-27xen/gntdev: Add initial support for dma-buf UAPIOleksandr Andrushchenko1-0/+31
Add UAPI and IOCTLs for dma-buf grant device driver extension: the extension allows userspace processes and kernel modules to use Xen backed dma-buf implementation. With this extension grant references to the pages of an imported dma-buf can be exported for other domain use and grant references coming from a foreign domain can be converted into a local dma-buf for local export. Implement basic initialization and stubs for Xen DMA buffers' support. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-07-27xen/gntdev: Make private routines/structures accessibleOleksandr Andrushchenko1-91/+43
This is in preparation for adding support of DMA buffer functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-07-27xen/gntdev: Allow mappings for DMA buffersOleksandr Andrushchenko1-2/+97
Allow mappings for DMA backed buffers if grant table module supports such: this extends grant device to not only map buffers made of balloon pages, but also from buffers allocated with dma_alloc_xxx. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-01-10xen/gntdev: Fix partial gntdev_mmap() cleanupRoss Lagerwall1-1/+3
When cleaning up after a partially successful gntdev_mmap(), unmap the successfully mapped grant pages otherwise Xen will kill the domain if in debug mode (Attempt to implicitly unmap a granted PTE) or Linux will kill the process and emit "BUG: Bad page map in process" if Xen is in release mode. This is only needed when use_ptemod is true because gntdev_put_map() will unmap grant pages itself when use_ptemod is false. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-01-10xen/gntdev: Fix off-by-one error when unmapping with holesRoss Lagerwall1-3/+1
If the requested range has a hole, the calculation of the number of pages to unmap is off by one. Fix it. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-10-25xen/gntdev: avoid out of bounds access in case of partial gntdev_mmap()Juergen Gross1-1/+1
In case gntdev_mmap() succeeds only partially in mapping grant pages it will leave some vital information uninitialized needed later for cleanup. This will lead to an out of bounds array access when unmapping the already mapped pages. So just initialize the data needed for unmapping the pages a little bit earlier. Cc: <stable@vger.kernel.org> Reported-by: Arthur Borsboom <arthurborsboom@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-09-01xen/gntdev: update to new mmu_notifier semanticJérôme Glisse1-8/+0
Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org (moderated for non-subscribers) Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-13drivers, xen: convert grant_map.users from atomic_t to refcount_tElena Reshetova1-5/+6
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-28xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancingBoris Ostrovsky1-1/+1
Commit 9c17d96500f7 ("xen/gntdev: Grant maps should not be subject to NUMA balancing") set VM_IO flag to prevent grant maps from being subjected to NUMA balancing. It was discovered recently that this flag causes get_user_pages() to always fail with -EFAULT. check_vma_flags __get_user_pages __get_user_pages_locked __get_user_pages_unlocked get_user_pages_fast iov_iter_get_pages dio_refill_pages do_direct_IO do_blockdev_direct_IO do_blockdev_direct_IO ext4_direct_IO_read generic_file_read_iter aio_run_iocb (which can happen if guest's vdisk has direct-io-safe option). To avoid this let's use VM_MIXEDMAP flag instead --- it prevents NUMA balancing just as VM_IO does and has no effect on check_vma_flags(). Cc: stable@vger.kernel.org Reported-by: Olaf Hering <olaf@aepfle.de> Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Hugh Dickins <hughd@google.com> Tested-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2016-07-06xen: use vma_pages().Muhammad Falak R Wani1-1/+1
Replace explicit computation of vma page count by a call to vma_pages(). Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-05-24xen/gntdev: reduce copy batch size to 16David Vrabel1-1/+1
IOCTL_GNTDEV_GRANT_COPY batches copy operations to reduce the number of hypercalls. The stack is used to avoid a memory allocation in a hot path. However, a batch size of 24 requires more than 1024 bytes of stack which in some configurations causes a compiler warning. xen/gntdev.c: In function ‘gntdev_ioctl_grant_copy’: xen/gntdev.c:949:1: warning: the frame size of 1248 bytes is larger than 1024 bytes [-Wframe-larger-than=] This is a harmless warning as there is still plenty of stack spare, but people keep trying to "fix" it. Reduce the batch size to 16 to reduce stack usage to less than 1024 bytes. This should have minimal impact on performance. Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-01-07xen/gntdev: add ioctl for grant copyDavid Vrabel1-0/+203
Add IOCTL_GNTDEV_GRANT_COPY to allow applications to copy between user space buffers and grant references. This interface is similar to the GNTTABOP_copy hypercall ABI except the local buffers are provided using a virtual address (instead of a GFN and offset). To avoid userspace from having to page align its buffers the driver will use two or more ops if required. If the ioctl returns 0, the application must check the status of each segment with the segments status field. If the ioctl returns a -ve error code (EINVAL or EFAULT), the status of individual ops is undefined. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2015-12-21xen/gntdev: constify mmu_notifier_ops structuresJulia Lawall1-1/+1
This mmu_notifier_ops structure is never modified, so declare it as const, like the other mmu_notifier_ops structures. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-11-26xen/gntdev: Grant maps should not be subject to NUMA balancingBoris Ostrovsky1-1/+1
Doing so will cause the grant to be unmapped and then, during fault handling, the fault to be mistakenly treated as NUMA hint fault. In addition, even if those maps could partcipate in NUMA balancing, it wouldn't provide any benefit since we are unable to determine physical page's node (even if/when VNUMA is implemented). Marking grant maps' VMAs as VM_IO will exclude them from being part of NUMA balancing. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-10mm: mark most vm_operations_struct constKirill A. Shutemov1-1/+1
With two exceptions (drm/qxl and drm/radeon) all vm_operations_struct structs should be constant. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30xen/gntdevt: Fix race condition in gntdev_release()Marek Marczykowski-Górecki1-0/+2
While gntdev_release() is called the MMU notifier is still registered and can traverse priv->maps list even if no pages are mapped (which is the case -- gntdev_release() is called after all). But gntdev_release() will clear that list, so make sure that only one of those things happens at the same time. Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Cc: <stable@vger.kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-06-17xen: Include xen/page.h rather than asm/xen/page.hJulien Grall1-1/+1
Using xen/page.h will be necessary later for using common xen page helpers. As xen/page.h already include asm/xen/page.h, always use the later. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: netdev@vger.kernel.org Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-27xen/grant: introduce func gnttab_unmap_refs_sync()Bob Liu1-25/+3
There are several place using gnttab async unmap and wait for completion, so move the common code to a function gnttab_unmap_refs_sync(). Signed-off-by: Bob Liu <bob.liu@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28xen/gntdev: provide find_special_page VMA operationDavid Vrabel1-0/+11
For a PV guest, use the find_special_page op to find the right page. To handle VMAs being split, remember the start of the original VMA so the correct index in the pages array can be calculated. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28xen/gntdev: mark userspace PTEs as special on x86 PV guestsDavid Vrabel1-0/+34
In an x86 PV guest, get_user_pages_fast() on a userspace address range containing foreign mappings does not work correctly because the M2P lookup of the MFN from a userspace PTE may return the wrong page. Force get_user_pages_fast() to fail on such addresses by marking the PTEs as special. If Xen has XENFEAT_gnttab_map_avail_bits (available since at least 4.0), we can do so efficiently in the grant map hypercall. Otherwise, it needs to be done afterwards. This is both inefficient and racy (the mapping is visible to the task before we fixup the PTEs), but will be fine for well-behaved applications that do not use the mapping until after the mmap() system call returns. Guests with XENFEAT_auto_translated_physmap (ARM and x86 HVM or PVH) do not need this since get_user_pages() has always worked correctly for them. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28xen/gntdev: safely unmap grants in case they are still in useJennifer Herbert1-5/+31
Use gnttab_unmap_refs_async() to wait until the mapped pages are no longer in use before unmapping them. This allows userspace programs to safely use Direct I/O and AIO to a network filesystem which may retain refs to pages in queued skbs after the filesystem I/O has completed. Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-28 19:55:24 +0300