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* xen/gntdev: do not set VM_PFNMAPStefano Stabellini2012-04-271-1/+1
| | | | | | | | | | | | | | | | 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 <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branches 'stable/backend.base.v3' and 'stable/gntalloc.v7' of ↵Linus Torvalds2011-05-191-2/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * '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,gntalloc: Remove unneeded VM flagsDaniel De Graaf2011-03-091-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <ian.campbell@citrix.com> Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [v2: Added in git commit "We are.." from email correspondence]
* | xen-gntdev: unlock on error path in gntdev_mmap()Dan Carpenter2011-03-241-1/+3
| | | | | | | | | | | | | | We should unlock here and also decrement the number of &map->users. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen-gntdev: return -EFAULT on copy_to_user failureDan Carpenter2011-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | 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 <error27@gmail.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen-gntdev: Use ballooned pages for grant mappingsDaniel De Graaf2011-03-161-33/+5
|/ | | | | | | | | | | | 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 <ian.campbell@citrix.com> Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: gntdev: fix build warningIan Campbell2011-03-091-2/+1
| | | | | | | | | | | | | 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 <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Add cast to pointerDaniel De Graaf2011-02-231-2/+2
| | | | | Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Fix incorrect use of zero handleDaniel De Graaf2011-02-231-7/+16
| | | | | | | | 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 <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: prevent using UNMAP_NOTIFY_CLEAR_BYTE on read-only mappingsDaniel De Graaf2011-02-141-1/+9
| | | | | Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Avoid double-mapping memoryDaniel De Graaf2011-02-141-3/+12
| | | | | | | | | | If an already-mapped area of the device was mapped into userspace a second time, a hypercall was incorrectly made to remap the memory again. Avoid the hypercall on later mmap calls, and fail the mmap call if a writable mapping is attempted on a read-only range. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Avoid unmapping ranges twiceDaniel De Graaf2011-02-141-2/+31
| | | | | | | | | | In paravirtualized domains, mn_invl_page or mn_invl_range_start can unmap a segment of a mapped region without unmapping all pages. When the region is later released, the pages will be unmapped twice, leading to an incorrect -EINVAL return. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Use map->vma for checking map validityDaniel De Graaf2011-02-141-6/+2
| | | | | | | | | The is_mapped flag used to be set at the completion of the map operation, but was not checked in all error paths. Use map->vma instead, which will now be cleared if the initial grant mapping fails. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Fix unmap notify on PV domainsDaniel De Graaf2011-02-141-2/+7
| | | | | | | | | | In paravirtualized guests, the struct page* for mappings is only a placeholder, and cannot be used to access the granted memory. Use the userspace mapping that we have set up in order to implement UNMAP_NOTIFY_CLEAR_BYTE. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Fix memory leak when mmap failsDaniel De Graaf2011-02-141-6/+8
| | | | | | | The error path did not decrement the reference count of the grant structure. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/gntalloc,gntdev: Add unmap notify ioctlDaniel De Graaf2011-02-141-1/+60
| | | | | | | | | This ioctl allows the users of a shared page to be notified when the other end exits abnormally. [v2: updated description in structs] Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Support mapping in HVM domainsDaniel De Graaf2011-02-141-34/+83
| | | | | | | | | | | | | | | | HVM does not allow direct PTE modification, so instead we request that Xen change its internal p2m mappings on the allocated pages and map the memory into userspace normally. Note: The HVM path for map and unmap is slightly different: HVM keeps the pages mapped until the area is deleted, while the PV case (use_ptemod being true) must unmap them when userspace unmaps the range. In the normal use case, this makes no difference to users since unmap time is deletion time. [v2: Expanded commit descr.] Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Add reference counting to mapsDaniel De Graaf2011-02-141-40/+27
| | | | | | | | | | | This allows userspace to perform mmap() on the gntdev device and then immediately close the filehandle or remove the mapping using the remove ioctl, with the mapped area remaining valid until unmapped. This also fixes an infinite loop when a gntdev device is closed without first unmapping all areas. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Use find_vma rather than iterating our vma list manuallyDaniel De Graaf2011-02-141-24/+8
| | | | | | | | This should be faster if many mappings exist, and also removes the only user of map->vma not related to PTE modification. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Change page limit to be global instead of per-openDaniel De Graaf2011-02-141-36/+14
| | | | | | | | | | | | | Because there is no limitation on how many times a user can open a given device file, an per-file-description limit on the number of pages granted offers little to no benefit. Change to a global limit and remove the ioctl() as the parameter can now be changed via sysfs. Xen tools changeset 22768:f8d801e5573e is needed to eliminate the error this change produces in xc_gnttab_set_max_grants. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen gntdev: use gnttab_map_refs and gnttab_unmap_refsStefano Stabellini2011-01-111-7/+30
| | | | | | | | | Use gnttab_map_refs and gnttab_unmap_refs to map and unmap the grant ref, so that we can have a corresponding struct page. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/gntdev: Fix circular locking dependencyDaniel De Graaf2011-01-111-2/+7
| | | | | | | | | | | | | | apply_to_page_range will acquire PTE lock while priv->lock is held, and mn_invl_range_start tries to acquire priv->lock with PTE already held. Fix by not holding priv->lock during the entire map operation. This is safe because map->vma is set nonzero while the lock is held, which will cause subsequent maps to fail and will cause the unmap ioctl (and other users of gntdev_del_map) to return -EBUSY until the area is unmapped. It is similarly impossible for gntdev_vma_close to be called while the vma is still being created. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/gntdev: stop using "token" argumentJeremy Fitzhardinge2011-01-111-2/+2
| | | | | | | | | | It's the struct page of the L1 pte page. But we can get its mfn by simply doing an arbitrary_virt_to_machine() on it anyway (which is the safe conservative choice; since we no longer allow HIGHPTE pages, we would never expect to be operating on a mapped pte page). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: gntdev: move use of GNTMAP_contains_pte next to the map_opIan Campbell2011-01-111-3/+5
| | | | | | | | | | | | | | | | | | | | This flag controls the meaning of gnttab_map_grant_ref.host_addr and specifies that the field contains a reference to the pte entry to be used to perform the mapping. Therefore move the use of this flag to the point at which we actually use a reference to the pte instead of something else, splitting up the usage of the flag in this way is confusing and potentially error prone. The other flags are all properties of the mapping itself as opposed to properties of the hypercall arguments and therefore it make sense to continue to pass them round in map->flags. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com> Cc: Derek G. Murray <Derek.Murray@cl.cam.ac.uk> Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/gntdev: add VM_PFNMAP to vmaJeremy Fitzhardinge2011-01-111-1/+1
| | | | | | | | These pages are from other domains, so don't have any local PFN. VM_PFNMAP is the closest concept Linux has to this. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/gntdev: allow usermode to map granted pagesGerd Hoffmann2011-01-111-0/+635
The gntdev driver allows usermode to map granted pages from other domains. This is typically used to implement a Xen backend driver in user mode. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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