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path: root/drivers/xen/gntdev.c
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2015-01-28xen/gntdev: provide find_special_page VMA operationDavid Vrabel
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 Vrabel
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 Herbert
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>
2015-01-28xen/gntdev: convert priv->lock to a mutexDavid Vrabel
Unmapping may require sleeping and we unmap while holding priv->lock, so convert it to a mutex. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28xen/grant-table: add helpers for allocating pagesDavid Vrabel
Add gnttab_alloc_pages() and gnttab_free_pages() to allocate/free pages suitable to for granted maps. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28xen/grant-table: pre-populate kernel unmap ops for xen_gnttab_unmap_refs()David Vrabel
When unmapping grants, instead of converting the kernel map ops to unmap ops on the fly, pre-populate the set of unmap ops. This allows the grant unmap for the kernel mappings to be trivially batched in the future. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-02-03Revert "xen/grant-table: Avoid m2p_override during mapping"Konrad Rzeszutek Wilk
This reverts commit 08ece5bb2312b4510b161a6ef6682f37f4eac8a1. As it breaks ARM builds and needs more attention on the ARM side. Acked-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-31xen/grant-table: Avoid m2p_override during mappingZoltan Kiss
The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the original functions were renamed to __gnttab_[un]map_refs, with a new parameter m2p_override - based on m2p_override either they follow the original behaviour, or just set the private flag and call set_phys_to_machine - gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with m2p_override false - a new function gnttab_[un]map_refs_userspace provides the old behaviour It also removes a stray space from page.h and change ret to 0 if XENFEAT_auto_translated_physmap, as that is the only possible return value there. v2: - move the storing of the old mfn in page->index to gnttab_map_refs - move the function header update to a separate patch v3: - a new approach to retain old behaviour where it needed - squash the patches into one v4: - move out the common bits from m2p* functions, and pass pfn/mfn as parameter - clear page->private before doing anything with the page, so m2p_find_override won't race with this v5: - change return value handling in __gnttab_[un]map_refs - remove a stray space in page.h - add detail why ret = 0 now at some places v6: - don't pass pfn to m2p* functions, just get it locally Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Suggested-by: David Vrabel <david.vrabel@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06xen/pvh: Piggyback on PVHVM for grant driver (v4)Konrad Rzeszutek Wilk
In PVH the shared grant frame is the PFN and not MFN, hence its mapped via the same code path as HVM. The allocation of the grant frame is done differently - we do not use the early platform-pci driver and have an ioremap area - instead we use balloon memory and stitch all of the non-contingous pages in a virtualized area. That means when we call the hypervisor to replace the GMFN with a XENMAPSPACE_grant_table type, we need to lookup the old PFN for every iteration instead of assuming a flat contingous PFN allocation. Lastly, we only use v1 for grants. This is because PVHVM is not able to use v2 due to no XENMEM_add_to_physmap calls on the error status page (see commit 69e8f430e243d657c2053f097efebc2e2cd559f0 xen/granttable: Disable grant v2 for HVM domains.) Until that is implemented this workaround has to be in place. Also per suggestions by Stefano utilize the PVHVM paths as they share common functionality. v2 of this patch moves most of the PVH code out in the arch/x86/xen/grant-table driver and touches only minimally the generic driver. v3, v4: fixes us some of the code due to earlier patches. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-08-20xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mappingStefano Stabellini
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 <stefano.stabellini@eu.citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: alex@alex.org.uk CC: dcrisan@flexiant.com [v1: Konrad fixed up the conflicts] Conflicts: arch/x86/xen/p2m.c
2013-06-28xen: Convert printks to pr_<level>Joe Perches
Convert printks to pr_<level> (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 <joe@perches.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-01-15xen/gntdev: remove erronous use of copy_to_userDaniel De Graaf
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 <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-01-15xen/gntdev: correctly unmap unlinked maps in mmu notifierDaniel De Graaf
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 <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-01-15xen/gntdev: fix unsafe vma accessDaniel De Graaf
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 <dgdegra@tycho.nsa.gov> Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-10-30xen/gntdev: don't leak memory from IOCTL_GNTDEV_MAP_GRANT_REFDavid Vrabel
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 <david.vrabel@citrix.com> Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-10-09mm: kill vma flag VM_RESERVED and mm->reserved_vm counterKonstantin Khlebnikov
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 <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-02Merge tag 'stable/for-linus-3.7-x86-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen update from Konrad Rzeszutek Wilk: "Features: - When hotplugging PCI devices in a PV guest we can allocate Xen-SWIOTLB later. - Cleanup Xen SWIOTLB. - Support pages out grants from HVM domains in the backends. - Support wild cards in xen-pciback.hide=(BDF) arguments. - Update grant status updates with upstream hypervisor. - Boot PV guests with more than 128GB. - Cleanup Xen MMU code/add comments. - Obtain XENVERS using a preferred method. - Lay out generic changes to support Xen ARM. - Allow privcmd ioctl for HVM (used to do only PV). - Do v2 of mmap_batch for privcmd ioctls. - If hypervisor saves the LED keyboard light - we will now instruct the kernel about its state. Fixes: - More fixes to Xen PCI backend for various calls/FLR/etc. - With more than 4GB in a 64-bit PV guest disable native SWIOTLB. - Fix up smatch warnings. - Fix up various return values in privmcmd and mm." * tag 'stable/for-linus-3.7-x86-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (48 commits) xen/pciback: Restore the PCI config space after an FLR. xen-pciback: properly clean up after calling pcistub_device_find() xen/vga: add the xen EFI video mode support xen/x86: retrieve keyboard shift status flags from hypervisor. xen/gndev: Xen backend support for paged out grant targets V4. xen-pciback: support wild cards in slot specifications xen/swiotlb: Fix compile warnings when using plain integer instead of NULL pointer. xen/swiotlb: Remove functions not needed anymore. xen/pcifront: Use Xen-SWIOTLB when initting if required. xen/swiotlb: For early initialization, return zero on success. xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used. xen/swiotlb: Move the error strings to its own function. xen/swiotlb: Move the nr_tbl determination in its own function. xen/arm: compile and run xenbus xen: resynchronise grant table status codes with upstream xen/privcmd: return -EFAULT on error xen/privcmd: Fix mmap batch ioctl error status copy back. xen/privcmd: add PRIVCMD_MMAPBATCH_V2 ioctl xen/mm: return more precise error from xen_remap_domain_range() xen/mmu: If the revector fails, don't attempt to revector anything else. ...
2012-09-12xen/m2p: do not reuse kmap_op->dev_bus_addrStefano Stabellini
If the caller passes a valid kmap_op to m2p_add_override, we use kmap_op->dev_bus_addr to store the original mfn, but dev_bus_addr is part of the interface with Xen and if we are batching the hypercalls it might not have been written by the hypervisor yet. That means that later on Xen will write to it and we'll think that the original mfn is actually what Xen has written to it. Rather than "stealing" struct members from kmap_op, keep using page->index to store the original mfn and add another parameter to m2p_remove_override to get the corresponding kmap_op instead. It is now responsibility of the caller to keep track of which kmap_op corresponds to a particular page in the m2p_override (gntdev, the only user of this interface that passes a valid kmap_op, is already doing that). CC: stable@kernel.org Reported-and-Tested-By: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-21xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static.Konrad Rzeszutek Wilk
There is no need for those functions/variables to be visible. Make them static and also fix the compile warnings of this sort: drivers/xen/<some file>.c: warning: symbol '<blah>' was not declared. Should it be static? Some of them just require including the header file that declares the functions. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-17xen/gntdev: do not set VM_PFNMAPStefano Stabellini
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. CC: stable@kernel.org Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-12-20xen/grant-table: Support mappings required by blkbackDaniel De Graaf
Add support for mappings without GNTMAP_contains_pte. This was not supported because the unmap operation assumed that this flag was being used; adding a parameter to the unmap operation to allow the PTE clearing to be disabled is sufficient to make unmap capable of supporting either mapping type. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> [v1: Fix cleanpatch warnings] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-12-20Merge commit 'v3.2-rc3' into stable/for-linus-3.3Konrad Rzeszutek Wilk
* commit 'v3.2-rc3': (412 commits) Linux 3.2-rc3 virtio-pci: make reset operation safer virtio-mmio: Correct the name of the guest features selector virtio: add HAS_IOMEM dependency to MMIO platform bus driver eCryptfs: Extend array bounds for all filename chars eCryptfs: Flush file in vma close eCryptfs: Prevent file create race condition regulator: TPS65910: Fix VDD1/2 voltage selector count i2c: Make i2cdev_notifier_call static i2c: Delete ANY_I2C_BUS i2c: Fix device name for 10-bit slave address i2c-algo-bit: Generate correct i2c address sequence for 10-bit target drm: integer overflow in drm_mode_dirtyfb_ioctl() Revert "of/irq: of_irq_find_parent: check for parent equal to child" drivers/gpu/vga/vgaarb.c: add missing kfree drm/radeon/kms/atom: unify i2c gpio table handling drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real ttm: Don't return the bo reserved on error path mount_subtree() pointless use-after-free iio: fix a leak due to improper use of anon_inode_getfd() ...
2011-11-21xen/gnt{dev,alloc}: reserve event channels for notifyDaniel De Graaf
When using the unmap notify ioctl, the event channel used for notification needs to be reserved to avoid it being deallocated prior to sending the notification. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-11-16xen-gntdev: integer overflow in gntdev_alloc_map()Dan Carpenter
The multiplications here can overflow resulting in smaller buffer sizes than expected. "count" comes from a copy_from_user(). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-11-06Merge branch 'stable/cleanups-3.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/cleanups-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: use static initializers in xen-balloon.c Xen: fix braces and tabs coding style issue in xenbus_probe.c Xen: fix braces coding style issue in xenbus_probe.h Xen: fix whitespaces,tabs coding style issue in drivers/xen/pci.c Xen: fix braces coding style issue in gntdev.c and grant-table.c Xen: fix whitespaces,tabs coding style issue in drivers/xen/events.c Xen: fix whitespaces,tabs coding style issue in drivers/xen/balloon.c Fix up trivial whitespace-conflicts in drivers/xen/{balloon.c,pci.c,xenbus/xenbus_probe.c}
2011-10-14xen/gntdev: Fix sleep-inside-spinlockDaniel De Graaf
BUG: sleeping function called from invalid context at /local/scratch/dariof/linux/kernel/mutex.c:271 in_atomic(): 1, irqs_disabled(): 0, pid: 3256, name: qemu-dm 1 lock held by qemu-dm/3256: #0: (&(&priv->lock)->rlock){......}, at: [<ffffffff813223da>] gntdev_ioctl+0x2bd/0x4d5 Pid: 3256, comm: qemu-dm Tainted: G W 3.1.0-rc8+ #5 Call Trace: [<ffffffff81054594>] __might_sleep+0x131/0x135 [<ffffffff816bd64f>] mutex_lock_nested+0x25/0x45 [<ffffffff8131c7c8>] free_xenballooned_pages+0x20/0xb1 [<ffffffff8132194d>] gntdev_put_map+0xa8/0xdb [<ffffffff816be546>] ? _raw_spin_lock+0x71/0x7a [<ffffffff813223da>] ? gntdev_ioctl+0x2bd/0x4d5 [<ffffffff8132243c>] gntdev_ioctl+0x31f/0x4d5 [<ffffffff81007d62>] ? check_events+0x12/0x20 [<ffffffff811433bc>] do_vfs_ioctl+0x488/0x4d7 [<ffffffff81007d4f>] ? xen_restore_fl_direct_reloc+0x4/0x4 [<ffffffff8109168b>] ? lock_release+0x21c/0x229 [<ffffffff81135cdd>] ? rcu_read_unlock+0x21/0x32 [<ffffffff81143452>] sys_ioctl+0x47/0x6a [<ffffffff816bfd82>] system_call_fastpath+0x16/0x1b gntdev_put_map tries to acquire a mutex when freeing pages back to the xenballoon pool, so it cannot be called with a spinlock held. In gntdev_release, the spinlock is not needed as we are freeing the structure later; in the ioctl, only the list manipulation needs to be under the lock. Reported-and-Tested-By: Dario Faggioli <dario.faggioli@citrix.com> Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29xen: modify kernel mappings corresponding to granted pagesStefano Stabellini
If we want to use granted pages for AIO, changing the mappings of a user vma and the corresponding p2m is not enough, we also need to update the kernel mappings accordingly. Currently this is only needed for pages that are created for user usages through /dev/xen/gntdev. As in, pages that have been in use by the kernel and use the P2M will not need this special mapping. However there are no guarantees that in the future the kernel won't start accessing pages through the 1:1 even for internal usage. In order to avoid the complexity of dealing with highmem, we allocated the pages lowmem. We issue a HYPERVISOR_grant_table_op right away in m2p_add_override and we remove the mappings using another HYPERVISOR_grant_table_op in m2p_remove_override. Considering that m2p_add_override and m2p_remove_override are called once per page we use multicalls and hypercall batching. Use the kmap_op pointer directly as argument to do the mapping as it is guaranteed to be present up until the unmapping is done. Before issuing any unmapping multicalls, we need to make sure that the mapping has already being done, because we need the kmap->handle to be set correctly. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v1: Removed GRANT_FRAME_BIT usage] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29xen: add an "highmem" parameter to alloc_xenballooned_pagesStefano Stabellini
Add an highmem parameter to alloc_xenballooned_pages, to allow callers to request lowmem or highmem pages. Fix the code style of free_xenballooned_pages' prototype. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-26Xen: fix braces coding style issue in gntdev.c and grant-table.cRuslan Pisarev
This is a patch to the gntdev.c and grant-table.c files that fixed up braces errors found by the checkpatch.pl tools. Signed-off-by: Ruslan Pisarev <ruslan@rpisarev.org.ua> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-19Merge branches 'stable/backend.base.v3' and 'stable/gntalloc.v7' of ↵Linus Torvalds
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
2011-03-24xen-gntdev: unlock on error path in gntdev_mmap()Dan Carpenter
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>
2011-03-24xen-gntdev: return -EFAULT on copy_to_user failureDan Carpenter
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>
2011-03-16xen-gntdev: Use ballooned pages for grant mappingsDaniel De Graaf
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>
2011-03-09xen/gntdev,gntalloc: Remove unneeded VM flagsDaniel De Graaf
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]
2011-03-09xen: gntdev: fix build warningIan Campbell
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>
2011-02-23xen-gntdev: Add cast to pointerDaniel De Graaf
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-23xen-gntdev: Fix incorrect use of zero handleDaniel De Graaf
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>
2011-02-14xen-gntdev: prevent using UNMAP_NOTIFY_CLEAR_BYTE on read-only mappingsDaniel De Graaf
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-14xen-gntdev: Avoid double-mapping memoryDaniel De Graaf
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>
2011-02-14xen-gntdev: Avoid unmapping ranges twiceDaniel De Graaf
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>
2011-02-14xen-gntdev: Use map->vma for checking map validityDaniel De Graaf
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>
2011-02-14xen-gntdev: Fix unmap notify on PV domainsDaniel De Graaf
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>
2011-02-14xen-gntdev: Fix memory leak when mmap failsDaniel De Graaf
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>
2011-02-14xen/gntalloc,gntdev: Add unmap notify ioctlDaniel De Graaf
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>
2011-02-14xen-gntdev: Support mapping in HVM domainsDaniel De Graaf
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>
2011-02-14xen-gntdev: Add reference counting to mapsDaniel De Graaf
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>
2011-02-14xen-gntdev: Use find_vma rather than iterating our vma list manuallyDaniel De Graaf
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>
2011-02-14xen-gntdev: Change page limit to be global instead of per-openDaniel De Graaf
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>
2011-01-11xen gntdev: use gnttab_map_refs and gnttab_unmap_refsStefano Stabellini
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>
2011-01-11xen/gntdev: Fix circular locking dependencyDaniel De Graaf
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>