kernel/git/stable/linux-stable.git/drivers/xen/gntdev.c, branch linux-3.12.y

xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing

2017-01-26T16:38:58+00:00

commit 30faaafdfa0c754c91bac60f216c9f34a2bfdf7e upstream. 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(). Reported-by: Olaf Hering Suggested-by: Hugh Dickins Signed-off-by: Boris Ostrovsky Acked-by: Hugh Dickins Tested-by: Olaf Hering Signed-off-by: Juergen Gross Signed-off-by: Jiri Slaby

xen/gntdev: Grant maps should not be subject to NUMA balancing

2016-01-25T14:15:39+00:00

commit 9c17d96500f78d7ecdb71ca6942830158bc75a2b upstream. 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 Signed-off-by: David Vrabel Signed-off-by: Jiri Slaby

xen/gntdev: convert priv->lock to a mutex

2015-09-30T09:13:09+00:00

commit 1401c00e59ea021c575f74612fe2dbba36d6a4ee upstream. Unmapping may require sleeping and we unmap while holding priv->lock, so convert it to a mutex. Signed-off-by: David Vrabel Reviewed-by: Stefano Stabellini Cc: Ian Campbell Signed-off-by: Jiri Slaby

xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping

2013-08-20T14:25:35+00:00

GNTTABOP_unmap_grant_ref unmaps a grant and replaces it with a 0 mapping instead of reinstating the original mapping. Doing so separately would be racy. To unmap a grant and reinstate the original mapping atomically we use GNTTABOP_unmap_and_replace. GNTTABOP_unmap_and_replace doesn't work with GNTMAP_contains_pte, so don't use it for kmaps. GNTTABOP_unmap_and_replace zeroes the mapping passed in new_addr so we have to reinstate it, however that is a per-cpu mapping only used for balloon scratch pages, so we can be sure that it's not going to be accessed while the mapping is not valid. Signed-off-by: Stefano Stabellini Reviewed-by: David Vrabel Acked-by: Konrad Rzeszutek Wilk CC: alex@alex.org.uk CC: dcrisan@flexiant.com [v1: Konrad fixed up the conflicts] Conflicts: arch/x86/xen/p2m.c

xen: Convert printks to pr_

2013-06-28T15:19:58+00:00

Convert printks to pr_ (excludes printk(KERN_DEBUG...) to be more consistent throughout the xen subsystem. Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME Coalesce formats and add missing word spaces Add missing newlines Align arguments and reflow to 80 columns Remove DRV_NAME from formats as pr_fmt adds the same content This does change some of the prefixes of these messages but it also does make them more consistent. Signed-off-by: Joe Perches Signed-off-by: Konrad Rzeszutek Wilk

xen/gntdev: remove erronous use of copy_to_user

2013-01-15T21:02:40+00:00

Since there is now a mapping of granted pages in kernel address space in both PV and HVM, use it for UNMAP_NOTIFY_CLEAR_BYTE instead of accessing memory via copy_to_user and triggering sleep-in-atomic warnings. Signed-off-by: Daniel De Graaf Signed-off-by: Konrad Rzeszutek Wilk

xen/gntdev: correctly unmap unlinked maps in mmu notifier

2013-01-15T21:01:30+00:00

If gntdev_ioctl_unmap_grant_ref is called on a range before unmapping it, the entry is removed from priv->maps and the later call to mn_invl_range_start won't find it to do the unmapping. Fix this by creating another list of freeable maps that the mmu notifier can search and use to unmap grants. Signed-off-by: Daniel De Graaf Signed-off-by: Konrad Rzeszutek Wilk

xen/gntdev: fix unsafe vma access

2013-01-15T21:01:06+00:00

In gntdev_ioctl_get_offset_for_vaddr, we need to hold mmap_sem while calling find_vma() to avoid potentially having the result freed out from under us. Similarly, the MMU notifier functions need to synchronize with gntdev_vma_close to avoid map->vma being freed during their iteration. Signed-off-by: Daniel De Graaf Reported-by: Al Viro Signed-off-by: Konrad Rzeszutek Wilk

xen/gntdev: don't leak memory from IOCTL_GNTDEV_MAP_GRANT_REF

2012-10-30T13:27:32+00:00

map->kmap_ops allocated in gntdev_alloc_map() wasn't freed by gntdev_put_map(). Add a gntdev_free_map() helper function to free everything allocated by gntdev_alloc_map(). Signed-off-by: David Vrabel Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk

mm: kill vma flag VM_RESERVED and mm->reserved_vm counter

2012-10-09T07:22:19+00:00

A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA, currently it lost original meaning but still has some effects: | effect | alternative flags -+------------------------+--------------------------------------------- 1| account as reserved_vm | VM_IO 2| skip in core dump | VM_IO, VM_DONTDUMP 3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP 4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP This patch removes reserved_vm counter from mm_struct. Seems like nobody cares about it, it does not exported into userspace directly, it only reduces total_vm showed in proc. Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP. remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP. remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP. [akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup] Signed-off-by: Konstantin Khlebnikov Cc: Alexander Viro Cc: Carsten Otte Cc: Chris Metcalf Cc: Cyrill Gorcunov Cc: Eric Paris Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Morris Cc: Jason Baron Cc: Kentaro Takeda Cc: Matt Helsley Cc: Nick Piggin Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Robert Richter Cc: Suresh Siddha Cc: Tetsuo Handa Cc: Venkatesh Pallipadi Acked-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds