Since 11c7ff17c9 (xen/grant-table: Force
to use v1 of grants.) the code for V2 grant tables is not used.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
arch_gnttab_map_frames() and arch_gnttab_unmap_frames() are called in
atomic context but were calling alloc_vm_area() which might sleep.
Also, if a driver attempts to allocate a grant ref from an interrupt
and the table needs expanding, then the CPU may already by in lazy MMU
mode and apply_to_page_range() will BUG when it tries to re-enable
lazy MMU mode.
These two functions are only used in PV guests.
Introduce arch_gnttab_init() to allocates the virtual address space in
advance.
Avoid the use of apply_to_page_range() by using saving and using the
array of PTE addresses from the alloc_vm_area() call.
N.B. 'alloc_vm_area' pre-allocates the pagetable so there is no need
to worry about having to do a PGD/PUD/PMD walk (like apply_to_page_range
does) and we can instead do set_pte.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
----
[v2: Add comment about alloc_vm_area]
[v3: Fix compile error found by 0-day bot]
Commit aa8532c322 (xen: refactor suspend
pre/post hooks) broke resuming PVHVM (auto-translated physmap) guests.
The gnttab_suspend() would clear the mapping for the grant table
frames, but the ->unmap_frames() call is only applicable to PV guests.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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 bulk of the original function (everything after the mapping hypercall)
is moved to arch-dependent set/clear_foreign_p2m_mapping
- the "if (xen_feature(XENFEAT_auto_translated_physmap))" branch goes to ARM
- therefore the ARM function could be much smaller, the m2p_override stubs
could be also removed
- on x86 the set_phys_to_machine calls were moved up to this new funcion
from m2p_override functions
- and m2p_override functions are only called when there is a kmap_ops param
It also removes a stray space from arch/x86/include/asm/xen/page.h.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Suggested-by: Anthony Liguori <aliguori@amazon.com>
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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>
On ARM, address size can be 32 bits or 64 bits (if CONFIG_ARCH_PHYS_ADDR_T_64BIT
is enabled).
We can't assume that the grant frame base address will always fits in an
unsigned long. Use phys_addr_t instead of unsigned long as argument for
gnttab_setup_auto_xlat_frames.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
We have the framework to use v2, but there are no backends that
actually use it. The end result is that on PV we use v2 grants
and on PVHVM v1. The v1 has a capacity of 512 grants per page while
the v2 has 256 grants per page. This means we lose about 50%
capacity - and if we want more than 16 VIFs (each VIF takes
512 grants), then we are hitting the max per guest of 32.
Oracle-bug: 16039922
CC: annie.li@oracle.com
CC: msw@amazon.com
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
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
69e8f430e2
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>
The 'xen_hvm_resume_frames' used to be an 'unsigned long'
and contain the virtual address of the grants. That was OK
for most architectures (PVHVM, ARM) were the grants are contiguous
in memory. That however is not the case for PVH - in which case
we will have to do a lookup for each virtual address for the PFN.
Instead of doing that, lets make it a structure which will contain
the array of PFNs, the virtual address and the count of said PFNs.
Also provide a generic functions: gnttab_setup_auto_xlat_frames and
gnttab_free_auto_xlat_frames to populate said structure with
appropriate values for PVHVM and ARM.
To round it off, change the name from 'xen_hvm_resume_frames' to
a more descriptive one - 'xen_auto_xlat_grant_frames'.
For PVH, in patch "xen/pvh: Piggyback on PVHVM for grant driver"
we will populate the 'xen_auto_xlat_grant_frames' by ourselves.
v2 moves the xen_remap in the gnttab_setup_auto_xlat_frames
and also introduces xen_unmap for gnttab_free_auto_xlat_frames.
Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v3: Based on top of 'asm/xen/page.h: remove redundant semicolon']
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
We have this odd scenario of where for PV paths we take a shortcut
but for the HVM paths we first ioremap xen_hvm_resume_frames, then
assign it to gnttab_shared.addr. This is needed because gnttab_map
uses gnttab_shared.addr.
Instead of having:
if (pv)
return gnttab_map
if (hvm)
...
gnttab_map
Lets move the HVM part before the gnttab_map and remove the
first call to gnttab_map.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
The function gnttab_max_grant_frames() returns the maximum amount
of frames (pages) of grants we can have. Unfortunatly it was
dependent on gnttab_init() having been run before to initialize
the boot max value (boot_max_nr_grant_frames).
This meant that users of gnttab_max_grant_frames would always
get a zero value if they called before gnttab_init() - such as
'platform_pci_init' (drivers/xen/platform-pci.c).
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
From: Eric Trudeau <etrudeau@broadcom.com>
xen_hvm_resume_frames stores the physical address of the grant table.
englighten.c was incorrectly setting it as if it was a page frame number.
This caused the table to be mapped into the guest at an unexpected physical
address.
Additionally, a warning is improved to include the grant table address which
failed in xen_remap.
Signed-off-by: Eric Trudeau <etrudeau@broadcom.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
When mapping/unmapping grant refs, call
set_phys_to_machine to update the P2M with the new mappings for
autotranslate guests.
This is (almost) a nop on x86.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Changes in v9:
- add in-code comments.
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>
ioremap can't be used to map ring pages on ARM because it uses device
memory caching attributes (MT_DEVICE*).
Introduce a Xen specific abstraction to map ring pages, called
xen_remap, that is defined as ioremap on x86 (no behavioral changes).
On ARM it explicitly calls __arm_ioremap with the right caching
attributes: MT_MEMORY.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull Xen fixes from Konrad Rzeszutek Wilk:
- CVE-2013-0190/XSA-40 (or stack corruption for 32-bit PV kernels)
- Fix racy vma access spotted by Al Viro
- Fix mmap batch ioctl potentially resulting in large O(n) page allcations.
- Fix vcpu online/offline BUG:scheduling while atomic..
- Fix unbound buffer scanning for more than 32 vCPUs.
- Fix grant table being incorrectly initialized
- Fix incorrect check in pciback
- Allow privcmd in backend domains.
Fix up whitespace conflict due to ugly merge resolution in Xen tree in
arch/arm/xen/enlighten.c
* tag 'stable/for-linus-3.8-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: Fix stack corruption in xen_failsafe_callback for 32bit PVOPS guests.
Revert "xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic."
xen/gntdev: remove erronous use of copy_to_user
xen/gntdev: correctly unmap unlinked maps in mmu notifier
xen/gntdev: fix unsafe vma access
xen/privcmd: Fix mmap batch ioctl.
Xen: properly bound buffer access when parsing cpu/*/availability
xen/grant-table: correctly initialize grant table version 1
x86/xen : Fix the wrong check in pciback
xen/privcmd: Relax access control in privcmd_ioctl_mmap
Commit 85ff6acb07 (xen/granttable: Grant
tables V2 implementation) changed the GREFS_PER_GRANT_FRAME macro from
a constant to a conditional expression. The expression depends on
grant_table_version being appropriately set. Unfortunately, at init
time grant_table_version will be 0. The GREFS_PER_GRANT_FRAME
conditional expression checks for "grant_table_version == 1", and
therefore returns the number of grant references per frame for v2.
This causes gnttab_init() to allocate fewer pages for gnttab_list, as
a frame can old half the number of v2 entries than v1 entries. After
gnttab_resume() is called, grant_table_version is appropriately
set. nr_init_grefs will then be miscalculated and gnttab_free_count
will hold a value larger than the actual number of free gref entries.
If a guest is heavily utilizing improperly initialized v1 grant
tables, memory corruption can occur. One common manifestation is
corruption of the vmalloc list, resulting in a poisoned pointer
derefrence when accessing /proc/meminfo or /proc/vmallocinfo:
[ 40.770064] BUG: unable to handle kernel paging request at 0000200200001407
[ 40.770083] IP: [<ffffffff811a6fb0>] get_vmalloc_info+0x70/0x110
[ 40.770102] PGD 0
[ 40.770107] Oops: 0000 [#1] SMP
[ 40.770114] CPU 10
This patch introduces a static variable, grefs_per_grant_frame, to
cache the calculated value. gnttab_init() now calls
gnttab_request_version() early so that grant_table_version and
grefs_per_grant_frame can be appropriately set. A few BUG_ON()s have
been added to prevent this type of bug from reoccurring in the future.
Signed-off-by: Matt Wilson <msw@amazon.com>
Reviewed-and-Tested-by: Steven Noonan <snoonan@amazon.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Annie Li <annie.li@oracle.com>
Cc: xen-devel@lists.xen.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v3.3 and newer
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, and __devinitdata from these
drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* commit 'v3.7-rc1': (10892 commits)
Linux 3.7-rc1
x86, boot: Explicitly include autoconf.h for hostprogs
perf: Fix UAPI fallout
ARM: config: make sure that platforms are ordered by option string
ARM: config: sort select statements alphanumerically
UAPI: (Scripted) Disintegrate include/linux/byteorder
UAPI: (Scripted) Disintegrate include/linux
UAPI: Unexport linux/blk_types.h
UAPI: Unexport part of linux/ppp-comp.h
perf: Handle new rbtree implementation
procfs: don't need a PATH_MAX allocation to hold a string representation of an int
vfs: embed struct filename inside of names_cache allocation if possible
audit: make audit_inode take struct filename
vfs: make path_openat take a struct filename pointer
vfs: turn do_path_lookup into wrapper around struct filename variant
audit: allow audit code to satisfy getname requests from its names_list
vfs: define struct filename and have getname() return it
btrfs: Fix compilation with user namespace support enabled
userns: Fix posix_acl_file_xattr_userns gid conversion
userns: Properly print bluetooth socket uids
...
This correctly sizes it as 64 bit on ARM but leaves it as unsigned
long on x86 (therefore no intended change on x86).
The long and ulong guest handles are now unused (and a bit dangerous)
so remove them.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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.
...
Since Xen-4.2, hvm domains may have portions of their memory paged out. When a
foreign domain (such as dom0) attempts to map these frames, the map will
initially fail. The hypervisor returns a suitable errno, and kicks an
asynchronous page-in operation carried out by a helper. The foreign domain is
expected to retry the mapping operation until it eventually succeeds. The
foreign domain is not put to sleep because itself could be the one running the
pager assist (typical scenario for dom0).
This patch adds support for this mechanism for backend drivers using grant
mapping and copying operations. Specifically, this covers the blkback and
gntdev drivers (which map foreign grants), and the netback driver (which copies
foreign grants).
* Add a retry method for grants that fail with GNTST_eagain (i.e. because the
target foreign frame is paged out).
* Insert hooks with appropriate wrappers in the aforementioned drivers.
The retry loop is only invoked if the grant operation status is GNTST_eagain.
It guarantees to leave a new status code different from GNTST_eagain. Any other
status code results in identical code execution as before.
The retry loop performs 256 attempts with increasing time intervals through a
32 second period. It uses msleep to yield while waiting for the next retry.
V2 after feedback from David Vrabel:
* Explicit MAX_DELAY instead of wrap-around delay into zero
* Abstract GNTST_eagain check into core grant table code for netback module.
V3 after feedback from Ian Campbell:
* Add placeholder in array of grant table error descriptions for unrelated
error code we jump over.
* Eliminate single map and retry macro in favor of a generic batch flavor.
* Some renaming.
* Bury most implementation in grant_table.c, cleaner interface.
V4 rebased on top of sync of Xen grant table interface headers.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[v5: Fixed whitespace issues]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
David Vrabel
Zoltan Kiss
Konrad Rzeszutek Wilk
Julien Grall
Eric Trudeau
Matt Wilson
Stefano Stabellini
Roger Pau Monne
Joe Perches
Linus Torvalds
Greg Kroah-Hartman
Ian Campbell
Andres Lagar-Cavilla