linux-stable.git/drivers/xen, branch v4.4.97

xen: don't print error message in case of missing Xenstore entry

2017-11-08T09:06:30+00:00

[ Upstream commit 4e93b6481c87ea5afde944a32b4908357ec58992 ]

When registering for the Xenstore watch of the node control/sysrq the
handler will be called at once. Don't issue an error message if the
Xenstore node isn't there, as it will be created only when an event
is being triggered.

Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen/manage: correct return value check on xenbus_scanf()

2017-11-08T09:06:30+00:00

[ Upstream commit 4fed1b125eb6252bde478665fc05d4819f774fa8 ]

A negative return value indicates an error; in fact the function at
present won't ever return zero.

Signed-off-by: Jan Beulich 
Reviewed-by: Juergen Gross 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen/gntdev: avoid out of bounds access in case of partial gntdev_mmap()

2017-11-02T08:40:49+00:00

commit 298d275d4d9bea3524ff4bc76678c140611d8a8d upstream.

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.

Reported-by: Arthur Borsboom 
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

fix xen_swiotlb_dma_mmap prototype

2017-10-05T07:41:48+00:00

xen_swiotlb_dma_mmap was backported from v4.10, but older
kernels before commit 00085f1efa38 ("dma-mapping: use unsigned long
for dma_attrs") use a different signature:

arm/xen/mm.c:202:10: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
  .mmap = xen_swiotlb_dma_mmap,
          ^~~~~~~~~~~~~~~~~~~~
arm/xen/mm.c:202:10: note: (near initialization for 'xen_swiotlb_dma_ops.mmap')

This adapts the patch to the old calling conventions.

Fixes: "swiotlb-xen: implement xen_swiotlb_dma_mmap callback"
Signed-off-by: Arnd Bergmann 
Reviewed-by: Stefano Stabellini 
Signed-off-by: Greg Kroah-Hartman

swiotlb-xen: implement xen_swiotlb_dma_mmap callback

2017-10-05T07:41:48+00:00

commit 7e91c7df29b5e196de3dc6f086c8937973bd0b88 upstream.

This function creates userspace mapping for the DMA-coherent memory.

Signed-off-by: Stefano Stabellini 
Signed-off-by: Oleksandr Dmytryshyn 
Signed-off-by: Andrii Anisov 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

xen: fix bio vec merging

2017-08-25T00:02:36+00:00

commit 462cdace790ac2ed6aad1b19c9c0af0143b6aab0 upstream.

The current test for bio vec merging is not fully accurate and can be
tricked into merging bios when certain grant combinations are used.
The result of these malicious bio merges is a bio that extends past
the memory page used by any of the originating bios.

Take into account the following scenario, where a guest creates two
grant references that point to the same mfn, ie: grant 1 -> mfn A,
grant 2 -> mfn A.

These references are then used in a PV block request, and mapped by
the backend domain, thus obtaining two different pfns that point to
the same mfn, pfn B -> mfn A, pfn C -> mfn A.

If those grants happen to be used in two consecutive sectors of a disk
IO operation becoming two different bios in the backend domain, the
checks in xen_biovec_phys_mergeable will succeed, because bfn1 == bfn2
(they both point to the same mfn). However due to the bio merging,
the backend domain will end up with a bio that expands past mfn A into
mfn A + 1.

Fix this by making sure the check in xen_biovec_phys_mergeable takes
into account the offset and the length of the bio, this basically
replicates whats done in __BIOVEC_PHYS_MERGEABLE using mfns (bus
addresses). While there also remove the usage of
__BIOVEC_PHYS_MERGEABLE, since that's already checked by the callers
of xen_biovec_phys_mergeable.

Reported-by: "Jan H. Schönherr" 
Signed-off-by: Roger Pau Monné 
Reviewed-by: Juergen Gross 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

swiotlb-xen: update dev_addr after swapping pages

2017-07-05T12:37:18+00:00

[ Upstream commit f1225ee4c8fcf09afaa199b8b1f0450f38b8cd11 ]

In xen_swiotlb_map_page and xen_swiotlb_map_sg_attrs, if the original
page is not suitable, we swap it for another page from the swiotlb
pool.

In these cases, we don't update the previously calculated dma address
for the page before calling xen_dma_map_page. Thus, we end up calling
xen_dma_map_page passing the wrong dev_addr, resulting in
xen_dma_map_page mistakenly assuming that the page is foreign when it is
local.

Fix the bug by updating dev_addr appropriately.

This change has no effect on x86, because xen_dma_map_page is a stub
there.

Signed-off-by: Stefano Stabellini 
Signed-off-by: Pooya Keshavarzi 
Tested-by: Pooya Keshavarzi 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen/privcmd: Support correctly 64KB page granularity when mapping memory

2017-06-14T11:16:22+00:00

commit 753c09b5652bb4fe53e2db648002ec64b32b8827 upstream.

Commit 5995a68 "xen/privcmd: Add support for Linux 64KB page granularity" did
not go far enough to support 64KB in mmap_batch_fn.

The variable 'nr' is the number of 4KB chunk to map. However, when Linux
is using 64KB page granularity the array of pages (vma->vm_private_data)
contain one page per 64KB. Fix it by incrementing st->index correctly.

Furthermore, st->va is not correctly incremented as PAGE_SIZE !=
XEN_PAGE_SIZE.

Fixes: 5995a68 ("xen/privcmd: Add support for Linux 64KB page granularity")
Reported-by: Feng Kan 
Signed-off-by: Julien Grall 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/acpi: upload PM state from init-domain to Xen

2017-03-30T07:35:18+00:00

commit 1914f0cd203c941bba72f9452c8290324f1ef3dc upstream.

This was broken in commit cd979883b9ed ("xen/acpi-processor:
fix enabling interrupts on syscore_resume"). do_suspend (from
xen/manage.c) and thus xen_resume_notifier never get called on
the initial-domain at resume (it is if running as guest.)

The rationale for the breaking change was that upload_pm_data()
potentially does blocking work in syscore_resume(). This patch
addresses the original issue by scheduling upload_pm_data() to
execute in workqueue context.

Cc: Stanislaw Gruszka 
Based-on-patch-by: Konrad Wilk 
Reviewed-by: Konrad Rzeszutek Wilk 
Reviewed-by: Stanislaw Gruszka 
Signed-off-by: Ankur Arora 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

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

2017-01-06T10:16:17+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: Greg Kroah-Hartman