Let's support empty memory devices -- memory devices that don't have a
memory device region in the current configuration. hv-balloon with an
optional memdev is the primary use case.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
We want to support memory devices that can automatically decide how many
memslots they will use. In the worst case, they have to use a single
memslot.
The target use cases are virtio-mem and the hyper-v balloon.
Let's calculate a reasonable limit such a memory device may use, and
instruct the device to make a decision based on that limit. Use a simple
heuristic that considers:
* A memslot soft-limit for all memory devices of 256; also, to not
consume too many memslots -- which could harm performance.
* Actually still free and unreserved memslots
* The percentage of the remaining device memory region that memory device
will occupy.
Further, while we properly check before plugging a memory device whether
there still is are free memslots, we have other memslot consumers (such as
boot memory, PCI BARs) that don't perform any checks and might dynamically
consume memslots without any prior reservation. So we might succeed in
plugging a memory device, but once we dynamically map a PCI BAR we would
be in trouble. Doing accounting / reservation / checks for all such
users is problematic (e.g., sometimes we might temporarily split boot
memory into two memslots, triggered by the BIOS).
We use the historic magic memslot number of 509 as orientation to when
supporting 256 memory devices -> memslots (leaving 253 for boot memory and
other devices) has been proven to work reliable. We'll fallback to
suggesting a single memslot if we don't have at least 509 total memslots.
Plugging vhost devices with less than 509 memslots available while we
have memory devices plugged that consume multiple memslots due to
automatic decisions can be problematic. Most configurations might just fail
due to "limit < used + reserved", however, it can also happen that these
memory devices would suddenly consume memslots that would actually be
required by other memslot consumers (boot, PCI BARs) later. Note that this
has always been sketchy with vhost devices that support only a small number
of memslots; but we don't want to make it any worse.So let's keep it simple
and simply reject plugging such vhost devices in such a configuration.
Eventually, all vhost devices that want to be fully compatible with such
memory devices should support a decent number of memslots (>= 509).
Message-ID: <20230926185738.277351-13-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
We want to support memory devices that have a dynamically managed memory
region container as device memory region. This device memory region maps
multiple RAM memory subregions (e.g., aliases to the same RAM memory
region), whereby these subregions can be (un)mapped on demand.
Each RAM subregion will consume a memslot in KVM and vhost, resulting in
such a new device consuming memslots dynamically, and initially usually
0. We already track the number of used vs. required memslots for all
memslots. From that, we can derive the number of reserved memslots that
must not be used otherwise.
The target use case is virtio-mem and the hyper-v balloon, which will
dynamically map aliases to RAM memory region into their device memory
region container.
Properly document what's supported and what's not and extend the vhost
memslot check accordingly.
Message-ID: <20230926185738.277351-10-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
We want to support memory devices that have a memory region container as
device memory region that maps multiple RAM memory regions. Let's start
by supporting memory devices that statically map multiple RAM memory
regions and, thereby, consume multiple memslots.
We already have one device that uses a container as device memory region:
NVDIMMs. However, a NVDIMM always ends up consuming exactly one memslot.
Let's add support for that by asking the memory device via a new
callback how many memslots it requires.
Message-ID: <20230926185738.277351-7-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Add a callback that can be used to express additional alignment
requirements (exceeding the ones from the memory region).
Will be used by virtio-mem to express special alignment requirements due
to manually configured, big block sizes (e.g., 1GB with an ordinary
memory-backend-ram). This avoids failing later when realizing, because
auto-detection wasn't able to assign a properly aligned address.
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20201008083029.9504-6-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.
Restricting the memory commands to machine.json pulls less
QAPI-generated code into user-mode.
Acked-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200913195348.1064154-7-philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.
Patch generated using:
$ ./scripts/codeconverter/converter.py -i \
--pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')
which will split "typdef struct { ... } TypedefName"
declarations.
Followed by:
$ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
$(git grep -l '' -- '*.[ch]')
which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h. Include hw/qdev-core.h there
instead.
hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.
While there, delete a few superfluous inclusions of hw/qdev-core.h.
Touching hw/qdev-properties.h now recompiles some 1200 objects.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
Some of the generated qapi-types-MODULE.h are included all over the
place. Changing a QAPI type can trigger massive recompiling. Top
scorers recompile more than 1000 out of some 6600 objects (not
counting tests and objects that don't depend on qemu/osdep.h):
6300 qapi/qapi-builtin-types.h
5700 qapi/qapi-types-run-state.h
3900 qapi/qapi-types-common.h
3300 qapi/qapi-types-sockets.h
3000 qapi/qapi-types-misc.h
3000 qapi/qapi-types-crypto.h
3000 qapi/qapi-types-job.h
3000 qapi/qapi-types-block-core.h
2800 qapi/qapi-types-block.h
1300 qapi/qapi-types-net.h
Clean up headers to include generated QAPI headers only where needed.
Impact is negligible except for hw/qdev-properties.h.
This header includes qapi/qapi-types-block.h and
qapi/qapi-types-misc.h. They are used only in expansions of property
definition macros such as DEFINE_PROP_BLOCKDEV_ON_ERROR() and
DEFINE_PROP_OFF_AUTO(). Moving their inclusion from
hw/qdev-properties.h to the users of these macros avoids pointless
recompiles. This is how other property definition macros, such as
DEFINE_PROP_NETDEV(), already work.
Improves things for some of the top scorers:
3600 qapi/qapi-types-common.h
2800 qapi/qapi-types-sockets.h
900 qapi/qapi-types-misc.h
2200 qapi/qapi-types-crypto.h
2100 qapi/qapi-types-job.h
2100 qapi/qapi-types-block-core.h
270 qapi/qapi-types-block.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-3-armbru@redhat.com>
With the new memory device functions in place, we can factor out
unplugging of memory devices completely.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-16-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
With the new memory device functions in place, we can factor out
plugging of memory devices completely.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-15-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
With all required memory device class functions in place, we can factor
out pre_plug handling of memory devices. Take proper care of errors. We
still have to carry along legacy_align required for pc compatibility
handling.
We will factor out tracing of the address separately in a follow-up
patch.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-14-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
To be able to factor out address assignment of memory devices, we will
have to read (get_addr()) and write (set_addr()) the address.
We can't use properties for this purpose, as properties are device
specific. E.g. while the address property for a DIMM is called "addr", it
might be called differently (e.g. "memaddr") for other devices.
Especially virtio based memory devices cannot use "addr" as that is already
reserved and used for the address on the bus (for the proxy device).
Also, it might be possible to have memory devices without address
properties (e.g. internal DIMM-like thingies).
In contrast to get_addr(), we expect that set_addr() can fail.
Keep it simple for now for pc-dimm and simply set the static property, that
will fail once realized.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-13-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
There are no remaining users of get_region_size() except
memory_device_get_region_size() itself. We can make
memory_device_get_region_size() work directly on get_memory_region()
instead and drop get_region_size().
In addition, we can now use memory_device_get_region_size() in pc-dimm
code to implement get_plugged_size()"
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-12-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The memory region is necessary for plugging/unplugging a memory device.
The region size (via get_region_size()) is no longer sufficient, as
besides the alignment, also the region itself is required in order to
add it to the device memory region of the machine via
- memory_region_add_subregion
- memory_region_del_subregion
So, to factor out plugging/unplugging of memory devices from pc-dimm
code, we have to factor out access to the memory region first.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-11-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
We will factor out get_memory_region() from pc-dimm to memory device code
soon. Once that is done, get_region_size() can be implemented
generically and essentially be replaced by
memory_device_get_region_size (and work only on get_memory_region()).
We have some users of get_memory_region() (spapr and pc-dimm code) that are
only interested in the size. So let's rework them to use
memory_device_get_region_size() first, then we can factor out
get_memory_region() and eventually remove get_region_size() without
touching the same code multiple times.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-10-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Document the functions. Don't document get_region_size(), as we will be
dropping/replacing that one soon.
Use same documentation style as in include/exec/memory.h, but don't
document the parameters, as they are self-explanatory.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-9-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Let's properly forward the errors, so errors from get_region_size() /
get_plugged_size() can be handled.
Users right now call both functions after the device has been realized,
which is will never fail, so it is fine to continue using error_abort.
While at it, remove a leftover error check (suggested by Igor).
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-8-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Registering the memory region for migration has do be done by the owner.
There could be cases, where we don't want to migrate the memory.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-8-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This mainly moves code, but does a handfull of optimizations:
- We pass the machine instead of the address space properties
- We check the hinted address directly and handle fragmented memory
better
- We make the search independent of pc-dimm
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-6-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
On the qmp level, we already have the concept of memory devices:
"query-memory-devices"
Right now, we only support NVDIMM and PCDIMM.
We want to map other devices later into the address space of the guest.
Such device could e.g. be virtio devices. These devices will have a
guest memory range assigned but won't be exposed via e.g. ACPI. We want
to make them look like memory device, but not glued to pc-dimm.
Especially, it will not always be possible to have TYPE_PC_DIMM as a parent
class (e.g. virtio devices). Let's use an interface instead. As a first
part, convert handling of
- qmp_pc_dimm_device_list
- get_plugged_memory_size
to our new model. plug/unplug stuff etc. will follow later.
A memory device will have to provide the following functions:
- get_addr(): Necessary, as the property "addr" can e.g. not be used for
virtio devices (already defined).
- get_plugged_size(): The amount this device offers to the guest as of
now.
- get_region_size(): Because this can later on be bigger than the
plugged size.
- fill_device_info(): Fill MemoryDeviceInfo, e.g. for qmp.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-2-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
