This is legal; the MemoryRegion will simply unreference all the
existing subregions and possibly bring them down with it as well.
However, it requires a bit of care to avoid an infinite loop.
Finalizing a memory region cannot trigger an address space update,
but memory_region_del_subregion errs on the side of caution and
might trigger a spurious update: avoid that by resetting mr->enabled
first.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1443689999-12182-2-git-send-email-armbru@redhat.com>
When we have guest visible IOMMUs, we allow notifiers to be registered
which will be informed of all changes to IOMMU mappings. This is used by
vfio to keep the host IOMMU mappings in sync with guest IOMMU mappings.
However, unlike with a memory region listener, an iommu notifier won't be
told about any mappings which already exist in the (guest) IOMMU at the
time it is registered. This can cause problems if hotplugging a VFIO
device onto a guest bus which had existing guest IOMMU mappings, but didn't
previously have an VFIO devices (and hence no host IOMMU mappings).
This adds a memory_region_iommu_replay() function to handle this case. It
replays any existing mappings in an IOMMU memory region to a specified
notifier. Because the IOMMU memory region doesn't internally remember the
granularity of the guest IOMMU it has a small hack where the caller must
specify a granularity at which to replay mappings.
If there are finer mappings in the guest IOMMU these will be reported in
the iotlb structures passed to the notifier which it must handle (probably
causing it to flag an error). This isn't new - the VFIO iommu notifier
must already handle notifications about guest IOMMU mappings too short
for it to represent in the host IOMMU.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Commit ef701d7 screwed up handling of out-of-memory conditions.
Before the commit, we report the error and exit(1), in one place. The
commit lifts the error handling up the call chain some, to three
places. Fine. Except it uses &error_abort in these places, changing
the behavior from exit(1) to abort(), and thus undoing the work of
commit 3922825 "exec: Don't abort when we can't allocate guest
memory".
The previous two commits fixed one of the three places, another one
was fixed in commit 33e0eb5. This commit fixes the third one.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-5-git-send-email-armbru@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Just specifying ops = NULL in some cases can be more convenient than having
two functions.
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 78a379ab1b6b30ab497db7971ad336dad1dbee76.1438758065.git.p.fedin@samsung.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Very often the owner of the aliased region is the same as the owner of the alias
region itself. When this happens, the reference count can never go back to 0 and
the owner is leaked. This is for example breaking hot-unplug of virtio-pci
devices (the device cannot be plugged back again with the same id).
Another common use for alias is to transform the system I/O address space
into an MMIO regions; in this case the aliased region never dies, so there
is no problem. Otherwise the owner is always the same for aliasing
and aliased region.
I checked all calls to memory_region_init_alias introduced after commit
dfde4e6 (memory: add ref/unref calls, 2013-05-06) and they do not need the
reference in order to keep the owner of the aliased region alive.
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For a board that has multiple framebuffer devices, both of them
might want to use DIRTY_MEMORY_VGA on the same memory region.
The lack of reference counting in memory_region_set_log makes
this very awkward to implement.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory_region_present() leaks a reference to a MemoryRegion in the
case "mr == container". While fixing it, avoid reference counting
altogether for memory_region_present(), by using RCU only.
The return value could in principle be already invalid immediately
after memory_region_present returns, but presumably the caller knows
that and it's using memory_region_present to probe for devices that
are unpluggable, or something like that. The RCU critical section
is needed anyway, because it protects as->current_map.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As memory_region_read/write_accessor will now be run also without BQL held,
we need to move coalesced MMIO flushing earlier in the dispatch process.
Cc: Frederic Konrad <fred.konrad@greensocs.com>
Message-Id: <1434646046-27150-5-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This introduces the memory region property "global_locking". It is true
by default. By setting it to false, a device model can request BQL-free
dispatching of region accesses to its r/w handlers. The actual BQL
break-up will be provided in a separate patch.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Frederic Konrad <fred.konrad@greensocs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1434646046-27150-4-git-send-email-pbonzini@redhat.com>
mr->terminates alone doesn't guarantee that we are looking at a RAM region.
mr->ram_addr also has to be checked, in order to distinguish RAM and I/O
regions.
So, do the following:
1) add a new define RAM_ADDR_INVALID, and test it in the assertions
instead of mr->terminates
2) IOMMU regions were not setting mr->ram_addr to a bogus value, initialize
it in the instance_init function so that the new assertions would fire
for IOMMU regions as well.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The cpu_physical_memory_reset_dirty() function is sometimes used
together with cpu_physical_memory_get_dirty(). This is not atomic since
two separate accesses to the dirty memory bitmap are made.
Turn cpu_physical_memory_reset_dirty() and
cpu_physical_memory_clear_dirty_range_type() into the atomic
cpu_physical_memory_test_and_clear_dirty().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-6-git-send-email-stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This cuts in half the cost of bitmap operations (which will become more
expensive when made atomic) during migration on non-VRAM regions.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The separate handling of DIRTY_MEMORY_MIGRATION, which does not
call log_start/log_stop callbacks when it changes in a region's
dirty logging mask, has caused several bugs.
One recent example is commit 4cc856f (kvm-all: Sync dirty-bitmap from
kvm before kvm destroy the corresponding dirty_bitmap, 2015-04-02).
Another performance problem is that KVM keeps tracking dirty pages
after a failed live migration, which causes bad performance due to
disallowing huge page mapping.
This patch removes the root cause of the problem by reporting
DIRTY_MEMORY_MIGRATION changes via log_start and log_stop.
Note that we now have to rebuild the FlatView when global dirty
logging is enabled or disabled; this ensures that log_start and
log_stop callbacks are invoked.
This will also be used to make the setting of bitmaps conditional.
In general, this patch lets users of the memory API ignore the
global state of dirty logging if they handle dirty logging
generically per region.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DIRTY_MEMORY_CODE is only needed for TCG. By adding it directly to
mr->dirty_log_mask, we avoid testing for TCG everywhere a region is
checked for the enabled/disabled state of dirty logging.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When the dirty log mask will also cover other bits than DIRTY_MEMORY_VGA,
some listeners may be interested in the overall zero/non-zero value of
the dirty log mask; others may be interested in the value of single bits.
For this reason, always call log_start/log_stop if bits have respectively
appeared or disappeared, and pass the old and new values of the dirty log
mask so that listeners can distinguish the kinds of change.
For example, KVM checks if dirty logging used to be completely disabled
(in log_start) or is now completely disabled (in log_stop). On the
other hand, Xen has to check manually if DIRTY_MEMORY_VGA changed,
since that is the only bit it cares about.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For now memory regions only track DIRTY_MEMORY_VGA individually, but
this will change soon. To support this, split memory_region_is_logging
in two functions: one that returns a given bit from dirty_log_mask,
and one that returns the entire mask. memory_region_is_logging gets an
extra parameter so that the compiler flags misuse.
While VGA-specific users (including the Xen listener!) will want to keep
checking that bit, KVM and vhost check for "any bit except migration"
(because migration is handled via the global start/stop listener
callbacks).
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DIRTY_MEMORY_MIGRATION is triggered by memory_global_dirty_log_start
and memory_global_dirty_log_stop, so it cannot be used with
memory_region_set_log.
Specify this in the documentation and assert it.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rather than retaining io_mem_read/write as simple wrappers around
the memory_region_dispatch_read/write functions, make the latter
public and change all the callers to use them, since we need to
touch all the callsites anyway to add MemTxAttrs and MemTxResult
support. Delete io_mem_read and io_mem_write entirely.
(All the callers currently pass MEMTXATTRS_UNSPECIFIED
and convert the return value back to bool or ignore it.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Define an API so that devices can register MemoryRegionOps whose read
and write callback functions are passed an arbitrary pointer to some
transaction attributes and can return a success-or-failure status code.
This will allow us to model devices which:
* behave differently for ARM Secure/NonSecure memory accesses
* behave differently for privileged/unprivileged accesses
* may return a transaction failure (causing a guest exception)
for erroneous accesses
This patch defines the new API and plumbs the attributes parameter through
to the memory.c public level functions io_mem_read() and io_mem_write(),
where it is currently dummied out.
The success/failure response indication is also propagated out to
io_mem_read() and io_mem_write(), which retain the old-style
boolean true-for-error return.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
This cleans up the official /machine namespace. In particular
/machine/system[0] and /machine/io[0], as well as entries with
non-sanitized node names such as "/machine/qemu extended regs[0]".
The actual MemoryRegion names remain unchanged.
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This fixes a use-after-free if do_address_space_destroy is executed
too late.
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
address_space_destroy_dispatch is called from an RCU callback and hence
outside the iothread mutex (BQL). However, after address_space_destroy
no new accesses can hit the destroyed AddressSpace so it is not necessary
to observe changes to the memory map. Move the memory_listener_unregister
call earlier, to make it thread-safe again.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Fixes: 374f2981d1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Do the entire lookup under RCU, which avoids atomic operations
in flatview_ref and flatview_unref.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace the flat_view_mutex with RCU, avoiding futex contention for
dataplane on large systems and many iothreads.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that memory_region_destroy can be called from an RCU callback,
checking the BQL-protected global memory_region_transaction_depth
does not make much sense.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add API to allocate resizeable RAM MR.
This looks just like regular RAM generally, but
has a special property that only a portion of it
(used_length) is actually used, and migrated.
This used_length size can change across reboots.
Follow up patches will change used_length for such blocks at migration,
making it easier to extend devices using such RAM (notably ACPI,
but in the future thinkably other ROMs) without breaking migration
compatibility or wasting ROM (guest) memory.
Device is notified on resize, so it can adjust if necessary.
Note: nothing prevents making all RAM resizeable in this way.
However, reviewers felt that only enabling this selectively will
make some class of errors easier to detect.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Add API to change MR size.
Will be used internally for RAM resize.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
introduce memory_region_get_alignment() that returns
underlying memory block alignment or 0 if it's not
relevant/implemented for backend.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The PCI MMIO might be disabled or the device in the reset state.
Make sure we do not dump these memory regions.
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add parameter errp to memory_region_init_rom_device and update all call
sites to propagate the error.
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
[Propagate the error out of realize. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add parameter errp to memory_region_init_ram and update all call sites
to pass in &error_abort.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add parameter errp to qemu_ram_alloc and qemu_ram_alloc_from_ptr so that
we can handle errors.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[Assert ptr != NULL in memory_region_init_ram_ptr. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Obsoleted by automatic object_property_add() arrayification.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
To support name retrieval of MemoryRegions that were created
dynamically (that is, not via memory_region_init and friends). We
cache the name in MemoryRegion's state as
object_get_canonical_path_component mallocs the returned value
so it's not suitable for direct return to callers. Memory already
frees the name field, so this will be garbage collected along with
the MR object.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rather than having the name as separate state. This prepares support
for creating a MemoryRegion dynamically (i.e. without
memory_region_init() and friends) and the MemoryRegion still getting
a usable name.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Despite being local to memory.c, use the helper function. This prepares
support for fully QOMifiying the name field of MR (which will remove
this state from MR completely).
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It doesn't change the MR and some prospective call sites will have
const MRs at hand.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function is empty after the previous patch, so remove it.
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Explicitly call object_unparent in the few places where we
will re-create the memory region. If the memory region is
simply being destroyed as part of device teardown, let QOM
handle it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We are not 64 bit any more since
08dafab4 memory: use 128-bit integers for sizes and intermediates
but the comment is forgotten to be updated.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
To allow devices to dynamically resize the device. The motivation is
to allow devices with variable size to init their memory_region
without size early and then correctly populate size at realize() time.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
QOM propertyify the .may-overlap and .priority fields. The setters
will re-add the memory as a subregion if needed (i.e. the values change
when the memory region is already contained).
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[Remove setters. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expose the already existing .parent and .addr fields as QOM properties.
.parent (i.e. the field describing the memory region that contains this
one in Memory hierachy) is renamed "container". This is to avoid
confusion with the QOM parent.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[Remove setters. Do not unref parent on releasing the property. Clean
up error propagation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
QOMify memory regions as an Object. The former init() and destroy()
routines become instance_init() and instance_finalize() resp.
memory_region_init() is re-implemented to be:
object_initialize() + set fields
memory_region_destroy() is re-implemented to call unparent().
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[Add newly-created MR as child, unparent on destruction. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini
David Gibson
Markus Armbruster
Pavel Fedin
Jan Kiszka
Stefan Hajnoczi
Gerd Hoffmann
Peter Maydell
Andreas Färber
Michael S. Tsirkin
Igor Mammedov
Nikunj A Dadhania
Hu Tao
Peter Crosthwaite
Fam Zheng