linux-toradex.git/drivers/xen/gntdev.c, branch v3.0.87

xen/gntdev: do not set VM_PFNMAP

2012-04-27T16:51:05+00:00

commit e8e937be971d706061dc56220ff3605ab77622a7 upstream.

Since we are using the m2p_override we do have struct pages
corresponding to the user vma mmap'ed by gntdev.

Removing the VM_PFNMAP flag makes get_user_pages work on that vma.
An example test case would be using a Xen userspace block backend
(QDISK) on a file on NFS using O_DIRECT.

Signed-off-by: Stefano Stabellini 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

Merge branches 'stable/backend.base.v3' and 'stable/gntalloc.v7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

2011-05-19T23:14:25+00:00

* 'stable/backend.base.v3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pci: Fix compiler error when CONFIG_XEN_PRIVILEGED_GUEST is not set.
  xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions.
  xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override.
  xen/irq: The Xen hypervisor cleans up the PIRQs if the other domain forgot.
  xen/irq: Export 'xen_pirq_from_irq' function.
  xen/irq: Add support to check if IRQ line is shared with other domains.
  xen/irq: Check if the PCI device is owned by a domain different than DOMID_SELF.
  xen/pci: Add xen_[find|register|unregister]_device_domain_owner functions.

* 'stable/gntalloc.v7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/gntdev,gntalloc: Remove unneeded VM flags

xen-gntdev: unlock on error path in gntdev_mmap()

2011-03-24T14:32:45+00:00

We should unlock here and also decrement the number of &map->users.

Signed-off-by: Dan Carpenter 
Signed-off-by: Konrad Rzeszutek Wilk

xen-gntdev: return -EFAULT on copy_to_user failure

2011-03-24T14:32:44+00:00

copy_to_user() returns the amount of data remaining to be copied.  We
want to return a negative error code here.  The upper layers just
call WARN_ON() if we return non-zero so this doesn't change the
behavior.  But returning -EFAULT is still cleaner.

Signed-off-by: Dan Carpenter 
Signed-off-by: Konrad Rzeszutek Wilk

xen-gntdev: Use ballooned pages for grant mappings

2011-03-16T14:05:36+00:00

Grant mappings cause the PFN<->MFN mapping to be lost on the pages used
for the mapping. Instead of leaking memory, use pages that have already
been ballooned out and so have no valid mapping. This removes the need
for the bad-page leak workaround as pages are repopulated by the balloon
driver.

Acked-by: Ian Campbell 
Signed-off-by: Daniel De Graaf 
Signed-off-by: Konrad Rzeszutek Wilk

xen/gntdev,gntalloc: Remove unneeded VM flags

2011-03-10T03:15:28+00:00

The only time when granted pages need to be treated specially is when
using Xen's PTE modification for grant mappings owned by another domain
(that is, only gntdev on PV guests).  Otherwise, the area does not
require VM_DONTCOPY and VM_PFNMAP, since it can be accessed just like
any other page of RAM.

Since the vm_operations_struct close operations decrement reference
counts, a corresponding open function that increments them is required
now that it is possible to have multiple references to a single area.

We are careful in the gntdev to check if we can remove those flags. The
reason that we need to be careful in gntdev on PV guests is because we are
not changing the PFN/MFN mapping on PV; instead, we change the application's
page tables to point to the other domain's memory. This means that the vma
cannot be copied without using another grant mapping hypercall; it also
requires special handling on unmap, which is the reason for gntdev's
dependency on the MMU notifier.

For gntalloc, this is not a concern - the pages are owned by the domain
using the gntalloc device, and can be mapped and unmapped in the same manner
as any other page of memory.

Acked-by: Ian Campbell 
Signed-off-by: Daniel De Graaf 
Signed-off-by: Konrad Rzeszutek Wilk 
[v2: Added in git commit "We are.." from email correspondence]

xen: gntdev: fix build warning

2011-03-10T00:59:19+00:00

addr is actually a virtual address so use an unsigned long. Fixes:

  CC      drivers/xen/gntdev.o
drivers/xen/gntdev.c: In function 'map_grant_pages':
drivers/xen/gntdev.c:268: warning: cast from pointer to integer of different size

Reduce the scope of the variable at the same time.

Signed-off-by: Ian Campbell 
Signed-off-by: Konrad Rzeszutek Wilk

xen-gntdev: Add cast to pointer

2011-02-23T15:10:34+00:00

Signed-off-by: Daniel De Graaf 
Signed-off-by: Konrad Rzeszutek Wilk

xen-gntdev: Fix incorrect use of zero handle

2011-02-23T15:10:34+00:00

The handle with numeric value 0 is a valid map handle, so it cannot
be used to indicate that a page has not been mapped. Use -1 instead.

Signed-off-by: Daniel De Graaf 
Signed-off-by: Konrad Rzeszutek Wilk

xen-gntdev: prevent using UNMAP_NOTIFY_CLEAR_BYTE on read-only mappings

2011-02-14T19:16:23+00:00

Signed-off-by: Daniel De Graaf 
Signed-off-by: Konrad Rzeszutek Wilk