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migration/next for 20180515 

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Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20180515' into staging

migration/next for 20180515

# gpg: Signature made Tue 15 May 2018 22:54:38 BST
# gpg:                using RSA key F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20180515: (40 commits)
  Migration+TLS: Fix crash due to double cleanup
  migration: Textual fixups for blocktime
  migration: update index field when delete or qsort RDMALocalBlock
  migration: update docs
  migration/hmp: add migrate_pause command
  migration/qmp: add command migrate-pause
  migration: introduce lock for to_dst_file
  hmp/migration: add migrate_recover command
  qmp/migration: new command migrate-recover
  migration: init dst in migration_object_init too
  migration: final handshake for the resume
  migration: setup ramstate for resume
  migration: synchronize dirty bitmap for resume
  migration: introduce SaveVMHandlers.resume_prepare
  migration: new message MIG_RP_MSG_RESUME_ACK
  migration: new cmd MIG_CMD_POSTCOPY_RESUME
  migration: new message MIG_RP_MSG_RECV_BITMAP
  migration: new cmd MIG_CMD_RECV_BITMAP
  migration: wakeup dst ram-load-thread for recover
  migration: new state "postcopy-recover"
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2018-05-17 11:10:12 +01:00
parent 61126a8b4b 8b7bf2bada
commit eb7514ae10
21 changed files with 1856 additions and 302 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

516
docs/devel/migration.rst
View File

@ -28,11 +28,11 @@ the guest to be stopped. Typically the time that the guest is
unresponsive during live migration is the low hundred of milliseconds
(notice that this depends on a lot of things).
Types of migration
==================
Transports
==========
Now that we have talked about live migration, there are several ways
to do migration:
The migration stream is normally just a byte stream that can be passed
over any transport.
- tcp migration: do the migration using tcp sockets
- unix migration: do the migration using unix sockets
@ -40,16 +40,16 @@ to do migration:
- fd migration: do the migration using an file descriptor that is
passed to QEMU. QEMU doesn't care how this file descriptor is opened.
All these four migration protocols use the same infrastructure to
In addition, support is included for migration using RDMA, which
transports the page data using ``RDMA``, where the hardware takes care of
transporting the pages, and the load on the CPU is much lower. While the
internals of RDMA migration are a bit different, this isn't really visible
outside the RAM migration code.
All these migration protocols use the same infrastructure to
save/restore state devices. This infrastructure is shared with the
savevm/loadvm functionality.
State Live Migration
====================
This is used for RAM and block devices. It is not yet ported to vmstate.
<Fill more information here>
Common infrastructure
=====================
@ -57,60 +57,75 @@ The files, sockets or fd's that carry the migration stream are abstracted by
the ``QEMUFile`` type (see `migration/qemu-file.h`). In most cases this
is connected to a subtype of ``QIOChannel`` (see `io/`).
Saving the state of one device
==============================
The state of a device is saved using intermediate buffers. There are
some helper functions to assist this saving.
For most devices, the state is saved in a single call to the migration
infrastructure; these are *non-iterative* devices. The data for these
devices is sent at the end of precopy migration, when the CPUs are paused.
There are also *iterative* devices, which contain a very large amount of
data (e.g. RAM or large tables). See the iterative device section below.
There is a new concept that we have to explain here: device state
version. When we migrate a device, we save/load the state as a series
of fields. Some times, due to bugs or new functionality, we need to
change the state to store more/different information. We use the
version to identify each time that we do a change. Each version is
associated with a series of fields saved. The `save_state` always saves
the state as the newer version. But `load_state` sometimes is able to
load state from an older version.
General advice for device developers
------------------------------------
Legacy way
----------
- The migration state saved should reflect the device being modelled rather
than the way your implementation works. That way if you change the implementation
later the migration stream will stay compatible. That model may include
internal state that's not directly visible in a register.
This way is going to disappear as soon as all current users are ported to VMSTATE.
- When saving a migration stream the device code may walk and check
the state of the device. These checks might fail in various ways (e.g.
discovering internal state is corrupt or that the guest has done something bad).
Consider carefully before asserting/aborting at this point, since the
normal response from users is that *migration broke their VM* since it had
apparently been running fine until then. In these error cases, the device
should log a message indicating the cause of error, and should consider
putting the device into an error state, allowing the rest of the VM to
continue execution.
Each device has to register two functions, one to save the state and
another to load the state back.
- The migration might happen at an inconvenient point,
e.g. right in the middle of the guest reprogramming the device, during
guest reboot or shutdown or while the device is waiting for external IO.
It's strongly preferred that migrations do not fail in this situation,
since in the cloud environment migrations might happen automatically to
VMs that the administrator doesn't directly control.
.. code:: c
- If you do need to fail a migration, ensure that sufficient information
is logged to identify what went wrong.
int register_savevm(DeviceState *dev,
const char *idstr,
int instance_id,
int version_id,
SaveStateHandler *save_state,
LoadStateHandler *load_state,
void *opaque);
- The destination should treat an incoming migration stream as hostile
(which we do to varying degrees in the existing code). Check that offsets
into buffers and the like can't cause overruns. Fail the incoming migration
in the case of a corrupted stream like this.
typedef void SaveStateHandler(QEMUFile *f, void *opaque);
typedef int LoadStateHandler(QEMUFile *f, void *opaque, int version_id);
- Take care with internal device state or behaviour that might become
migration version dependent. For example, the order of PCI capabilities
is required to stay constant across migration. Another example would
be that a special case handled by subsections (see below) might become
much more common if a default behaviour is changed.
The important functions for the device state format are the `save_state`
and `load_state`. Notice that `load_state` receives a version_id
parameter to know what state format is receiving. `save_state` doesn't
have a version_id parameter because it always uses the latest version.
- The state of the source should not be changed or destroyed by the
outgoing migration. Migrations timing out or being failed by
higher levels of management, or failures of the destination host are
not unusual, and in that case the VM is restarted on the source.
Note that the management layer can validly revert the migration
even though the QEMU level of migration has succeeded as long as it
does it before starting execution on the destination.
- Buses and devices should be able to explicitly specify addresses when
instantiated, and management tools should use those. For example,
when hot adding USB devices it's important to specify the ports
and addresses, since implicit ordering based on the command line order
may be different on the destination. This can result in the
device state being loaded into the wrong device.
VMState
-------
The legacy way of saving/loading state of the device had the problem
that we have to maintain two functions in sync. If we did one change
in one of them and not in the other, we would get a failed migration.
VMState changed the way that state is saved/loaded. Instead of using
a function to save the state and another to load it, it was changed to
a declarative way of what the state consisted of. Now VMState is able
to interpret that definition to be able to load/save the state. As
the state is declared only once, it can't go out of sync in the
save/load functions.
Most device data can be described using the ``VMSTATE`` macros (mostly defined
in ``include/migration/vmstate.h``).
An example (from hw/input/pckbd.c)
@ -137,103 +152,99 @@ We registered this with:
vmstate_register(NULL, 0, &vmstate_kbd, s);
Note: talk about how vmstate <-> qdev interact, and what the instance ids mean.
For devices that are `qdev` based, we can register the device in the class
init function:
You can search for ``VMSTATE_*`` macros for lots of types used in QEMU in
include/hw/hw.h.
.. code:: c
More about versions
-------------------
dc->vmsd = &vmstate_kbd_isa;
Version numbers are intended for major incompatible changes to the
migration of a device, and using them breaks backwards-migration
compatibility; in general most changes can be made by adding Subsections
(see below) or _TEST macros (see below) which won't break compatibility.
The VMState macros take care of ensuring that the device data section
is formatted portably (normally big endian) and make some compile time checks
against the types of the fields in the structures.
You can see that there are several version fields:
VMState macros can include other VMStateDescriptions to store substructures
(see ``VMSTATE_STRUCT_``), arrays (``VMSTATE_ARRAY_``) and variable length
arrays (``VMSTATE_VARRAY_``). Various other macros exist for special
cases.
- `version_id`: the maximum version_id supported by VMState for that device.
- `minimum_version_id`: the minimum version_id that VMState is able to understand
for that device.
- `minimum_version_id_old`: For devices that were not able to port to vmstate, we can
assign a function that knows how to read this old state. This field is
ignored if there is no `load_state_old` handler.
Note that the format on the wire is still very raw; i.e. a VMSTATE_UINT32
ends up with a 4 byte bigendian representation on the wire; in the future
it might be possible to use a more structured format.
So, VMState is able to read versions from minimum_version_id to
version_id. And the function ``load_state_old()`` (if present) is able to
load state from minimum_version_id_old to minimum_version_id. This
function is deprecated and will be removed when no more users are left.
Legacy way
----------
Saving state will always create a section with the 'version_id' value
and thus can't be loaded by any older QEMU.
This way is going to disappear as soon as all current users are ported to VMSTATE;
although converting existing code can be tricky, and thus 'soon' is relative.
Massaging functions
-------------------
Each device has to register two functions, one to save the state and
another to load the state back.
Sometimes, it is not enough to be able to save the state directly
from one structure, we need to fill the correct values there. One
example is when we are using kvm. Before saving the cpu state, we
need to ask kvm to copy to QEMU the state that it is using. And the
opposite when we are loading the state, we need a way to tell kvm to
load the state for the cpu that we have just loaded from the QEMUFile.
.. code:: c
The functions to do that are inside a vmstate definition, and are called:
int register_savevm_live(DeviceState *dev,
const char *idstr,
int instance_id,
int version_id,
SaveVMHandlers *ops,
void *opaque);
- ``int (*pre_load)(void *opaque);``
Two functions in the ``ops`` structure are the `save_state`
and `load_state` functions. Notice that `load_state` receives a version_id
parameter to know what state format is receiving. `save_state` doesn't
have a version_id parameter because it always uses the latest version.
This function is called before we load the state of one device.
Note that because the VMState macros still save the data in a raw
format, in many cases it's possible to replace legacy code
with a carefully constructed VMState description that matches the
byte layout of the existing code.
- ``int (*post_load)(void *opaque, int version_id);``
Changing migration data structures
----------------------------------
This function is called after we load the state of one device.
- ``int (*pre_save)(void *opaque);``
This function is called before we save the state of one device.
Example: You can look at hpet.c, that uses the three function to
massage the state that is transferred.
If you use memory API functions that update memory layout outside
initialization (i.e., in response to a guest action), this is a strong
indication that you need to call these functions in a `post_load` callback.
Examples of such memory API functions are:
- memory_region_add_subregion()
- memory_region_del_subregion()
- memory_region_set_readonly()
- memory_region_set_enabled()
- memory_region_set_address()
- memory_region_set_alias_offset()
When we migrate a device, we save/load the state as a series
of fields. Sometimes, due to bugs or new functionality, we need to
change the state to store more/different information. Changing the migration
state saved for a device can break migration compatibility unless
care is taken to use the appropriate techniques. In general QEMU tries
to maintain forward migration compatibility (i.e. migrating from
QEMU n->n+1) and there are users who benefit from backward compatibility
as well.
Subsections
-----------
The use of version_id allows to be able to migrate from older versions
to newer versions of a device. But not the other way around. This
makes very complicated to fix bugs in stable branches. If we need to
add anything to the state to fix a bug, we have to disable migration
to older versions that don't have that bug-fix (i.e. a new field).
The most common structure change is adding new data, e.g. when adding
a newer form of device, or adding that state that you previously
forgot to migrate. This is best solved using a subsection.
But sometimes, that bug-fix is only needed sometimes, not always. For
instance, if the device is in the middle of a DMA operation, it is
using a specific functionality, ....
It is impossible to create a way to make migration from any version to
any other version to work. But we can do better than only allowing
migration from older versions to newer ones. For that fields that are
only needed sometimes, we add the idea of subsections. A subsection
is "like" a device vmstate, but with a particularity, it has a Boolean
function that tells if that values are needed to be sent or not. If
this functions returns false, the subsection is not sent.
A subsection is "like" a device vmstate, but with a particularity, it
has a Boolean function that tells if that values are needed to be sent
or not. If this functions returns false, the subsection is not sent.
Subsections have a unique name, that is looked for on the receiving
side.
On the receiving side, if we found a subsection for a device that we
don't understand, we just fail the migration. If we understand all
the subsections, then we load the state with success.
the subsections, then we load the state with success. There's no check
that a subsection is loaded, so a newer QEMU that knows about a subsection
can (with care) load a stream from an older QEMU that didn't send
the subsection.
If the new data is only needed in a rare case, then the subsection
can be made conditional on that case and the migration will still
succeed to older QEMUs in most cases. This is OK for data that's
critical, but in some use cases it's preferred that the migration
should succeed even with the data missing. To support this the
subsection can be connected to a device property and from there
to a versioned machine type.
One important note is that the post_load() function is called "after"
loading all subsections, because a newer subsection could change same
value that it uses.
value that it uses. A flag, and the combination of pre_load and post_load
can be used to detect whether a subsection was loaded, and to
fall back on default behaviour when the subsection isn't present.
Example:
@ -288,9 +299,13 @@ save/send this state when we are in the middle of a pio operation
not enabled, the values on that fields are garbage and don't need to
be sent.
Connecting subsections to properties
------------------------------------
Using a condition function that checks a 'property' to determine whether
to send a subsection allows backwards migration compatibility when
new subsections are added.
to send a subsection allows backward migration compatibility when
new subsections are added, especially when combined with versioned
machine types.
For example:
@ -305,21 +320,7 @@ For example:
Now that subsection will not be generated when using an older
machine type and the migration stream will be accepted by older
QEMU versions. pre-load functions can be used to initialise state
on the newer version so that they default to suitable values
when loading streams created by older QEMU versions that do not
generate the subsection.
In some cases subsections are added for data that had been accidentally
omitted by earlier versions; if the missing data causes the migration
process to succeed but the guest to behave badly then it may be better
to send the subsection and cause the migration to explicitly fail
with the unknown subsection error. If the bad behaviour only happens
with certain data values, making the subsection conditional on
the data value (rather than the machine type) allows migrations to succeed
in most cases. In general the preference is to tie the subsection to
the machine type, and allow reliable migrations, unless the behaviour
from omission of the subsection is really bad.
QEMU versions.
Not sending existing elements
-----------------------------
@ -328,9 +329,13 @@ Sometimes members of the VMState are no longer needed:
- removing them will break migration compatibility
- making them version dependent and bumping the version will break backwards migration compatibility.
- making them version dependent and bumping the version will break backward migration
compatibility.
The best way is to:
Adding a dummy field into the migration stream is normally the best way to preserve
compatibility.
If the field really does need to be removed then:
a) Add a new property/compatibility/function in the same way for subsections above.
b) replace the VMSTATE macro with the _TEST version of the macro, e.g.:
@ -342,18 +347,208 @@ The best way is to:
``VMSTATE_UINT32_TEST(foo, barstruct, pre_version_baz)``
Sometime in the future when we no longer care about the ancient versions these can be killed off.
Note that for backward compatibility it's important to fill in the structure with
data that the destination will understand.
Any difference in the predicates on the source and destination will end up
with different fields being enabled and data being loaded into the wrong
fields; for this reason conditional fields like this are very fragile.
Versions
--------
Version numbers are intended for major incompatible changes to the
migration of a device, and using them breaks backward-migration
compatibility; in general most changes can be made by adding Subsections
(see above) or _TEST macros (see above) which won't break compatibility.
Each version is associated with a series of fields saved. The `save_state` always saves
the state as the newer version. But `load_state` sometimes is able to
load state from an older version.
You can see that there are several version fields:
- `version_id`: the maximum version_id supported by VMState for that device.
- `minimum_version_id`: the minimum version_id that VMState is able to understand
for that device.
- `minimum_version_id_old`: For devices that were not able to port to vmstate, we can
assign a function that knows how to read this old state. This field is
ignored if there is no `load_state_old` handler.
VMState is able to read versions from minimum_version_id to
version_id. And the function ``load_state_old()`` (if present) is able to
load state from minimum_version_id_old to minimum_version_id. This
function is deprecated and will be removed when no more users are left.
There are *_V* forms of many ``VMSTATE_`` macros to load fields for version dependent fields,
e.g.
.. code:: c
VMSTATE_UINT16_V(ip_id, Slirp, 2),
only loads that field for versions 2 and newer.
Saving state will always create a section with the 'version_id' value
and thus can't be loaded by any older QEMU.
Massaging functions
-------------------
Sometimes, it is not enough to be able to save the state directly
from one structure, we need to fill the correct values there. One
example is when we are using kvm. Before saving the cpu state, we
need to ask kvm to copy to QEMU the state that it is using. And the
opposite when we are loading the state, we need a way to tell kvm to
load the state for the cpu that we have just loaded from the QEMUFile.
The functions to do that are inside a vmstate definition, and are called:
- ``int (*pre_load)(void *opaque);``
This function is called before we load the state of one device.
- ``int (*post_load)(void *opaque, int version_id);``
This function is called after we load the state of one device.
- ``int (*pre_save)(void *opaque);``
This function is called before we save the state of one device.
Example: You can look at hpet.c, that uses the three function to
massage the state that is transferred.
The ``VMSTATE_WITH_TMP`` macro may be useful when the migration
data doesn't match the stored device data well; it allows an
intermediate temporary structure to be populated with migration
data and then transferred to the main structure.
If you use memory API functions that update memory layout outside
initialization (i.e., in response to a guest action), this is a strong
indication that you need to call these functions in a `post_load` callback.
Examples of such memory API functions are:
- memory_region_add_subregion()
- memory_region_del_subregion()
- memory_region_set_readonly()
- memory_region_set_enabled()
- memory_region_set_address()
- memory_region_set_alias_offset()
Iterative device migration
--------------------------
Some devices, such as RAM, Block storage or certain platform devices,
have large amounts of data that would mean that the CPUs would be
paused for too long if they were sent in one section. For these
devices an *iterative* approach is taken.
The iterative devices generally don't use VMState macros
(although it may be possible in some cases) and instead use
qemu_put_*/qemu_get_* macros to read/write data to the stream. Specialist
versions exist for high bandwidth IO.
An iterative device must provide:
- A ``save_setup`` function that initialises the data structures and
transmits a first section containing information on the device. In the
case of RAM this transmits a list of RAMBlocks and sizes.
- A ``load_setup`` function that initialises the data structures on the
destination.
- A ``save_live_pending`` function that is called repeatedly and must
indicate how much more data the iterative data must save. The core
migration code will use this to determine when to pause the CPUs
and complete the migration.
- A ``save_live_iterate`` function (called after ``save_live_pending``
when there is significant data still to be sent). It should send
a chunk of data until the point that stream bandwidth limits tell it
to stop. Each call generates one section.
- A ``save_live_complete_precopy`` function that must transmit the
last section for the device containing any remaining data.
- A ``load_state`` function used to load sections generated by
any of the save functions that generate sections.
- ``cleanup`` functions for both save and load that are called
at the end of migration.
Note that the contents of the sections for iterative migration tend
to be open-coded by the devices; care should be taken in parsing
the results and structuring the stream to make them easy to validate.
Device ordering
---------------
There are cases in which the ordering of device loading matters; for
example in some systems where a device may assert an interrupt during loading,
if the interrupt controller is loaded later then it might lose the state.
Some ordering is implicitly provided by the order in which the machine
definition creates devices, however this is somewhat fragile.
The ``MigrationPriority`` enum provides a means of explicitly enforcing
ordering. Numerically higher priorities are loaded earlier.
The priority is set by setting the ``priority`` field of the top level
``VMStateDescription`` for the device.
Stream structure
================
The stream tries to be word and endian agnostic, allowing migration between hosts
of different characteristics running the same VM.
- Header
- Magic
- Version
- VM configuration section
- Machine type
- Target page bits
- List of sections
Each section contains a device, or one iteration of a device save.
- section type
- section id
- ID string (First section of each device)
- instance id (First section of each device)
- version id (First section of each device)
- <device data>
- Footer mark
- EOF mark
- VM Description structure
Consisting of a JSON description of the contents for analysis only
The ``device data`` in each section consists of the data produced
by the code described above. For non-iterative devices they have a single
section; iterative devices have an initial and last section and a set
of parts in between.
Note that there is very little checking by the common code of the integrity
of the ``device data`` contents, that's up to the devices themselves.
The ``footer mark`` provides a little bit of protection for the case where
the receiving side reads more or less data than expected.
The ``ID string`` is normally unique, having been formed from a bus name
and device address, PCI devices and storage devices hung off PCI controllers
fit this pattern well. Some devices are fixed single instances (e.g. "pc-ram").
Others (especially either older devices or system devices which for
some reason don't have a bus concept) make use of the ``instance id``
for otherwise identically named devices.
Return path
-----------
In most migration scenarios there is only a single data path that runs
from the source VM to the destination, typically along a single fd (although
possibly with another fd or similar for some fast way of throwing pages across).
Only a unidirectional stream is required for normal migration, however a
``return path`` can be created when bidirectional communication is desired.
This is primarily used by postcopy, but is also used to return a success
flag to the source at the end of migration.
However, some uses need two way communication; in particular the Postcopy
destination needs to be able to request pages on demand from the source.
For these scenarios there is a 'return path' from the destination to the source;
``qemu_file_get_return_path(QEMUFile* fwdpath)`` gives the QEMUFile* for the return
path.
@ -632,3 +827,28 @@ Retro-fitting postcopy to existing clients is possible:
identified and the implication understood; for example if the
guest memory access is made while holding a lock then all other
threads waiting for that lock will also be blocked.
Firmware
========
Migration migrates the copies of RAM and ROM, and thus when running
on the destination it includes the firmware from the source. Even after
resetting a VM, the old firmware is used. Only once QEMU has been restarted
is the new firmware in use.
- Changes in firmware size can cause changes in the required RAMBlock size
to hold the firmware and thus migration can fail. In practice it's best
to pad firmware images to convenient powers of 2 with plenty of space
for growth.
- Care should be taken with device emulation code so that newer
emulation code can work with older firmware to allow forward migration.
- Care should be taken with newer firmware so that backward migration
to older systems with older device emulation code will work.
In some cases it may be best to tie specific firmware versions to specific
versioned machine types to cut down on the combinations that will need
support. This is also useful when newer versions of firmware outgrow
the padding.

34
hmp-commands.hx
View File

@ -897,13 +897,14 @@ ETEXI
{
.name = "migrate",
.args_type = "detach:-d,blk:-b,inc:-i,uri:s",
.params = "[-d] [-b] [-i] uri",
.args_type = "detach:-d,blk:-b,inc:-i,resume:-r,uri:s",
.params = "[-d] [-b] [-i] [-r] uri",
.help = "migrate to URI (using -d to not wait for completion)"
"\n\t\t\t -b for migration without shared storage with"
" full copy of disk\n\t\t\t -i for migration without "
"shared storage with incremental copy of disk "
"(base image shared between src and destination)",
"(base image shared between src and destination)"
"\n\t\t\t -r to resume a paused migration",
.cmd = hmp_migrate,
},
@ -956,7 +957,34 @@ STEXI
@findex migrate_incoming
Continue an incoming migration using the @var{uri} (that has the same syntax
as the -incoming option).
ETEXI
{
.name = "migrate_recover",
.args_type = "uri:s",
.params = "uri",
.help = "Continue a paused incoming postcopy migration",
.cmd = hmp_migrate_recover,
},
STEXI
@item migrate_recover @var{uri}
@findex migrate_recover
Continue a paused incoming postcopy migration using the @var{uri}.
ETEXI
{
.name = "migrate_pause",
.args_type = "",
.params = "",
.help = "Pause an ongoing migration (postcopy-only)",
.cmd = hmp_migrate_pause,
},
STEXI
@item migrate_pause
@findex migrate_pause
Pause an ongoing migration. Currently it only supports postcopy.
ETEXI
{

23
hmp.c
View File

@ -1517,6 +1517,25 @@ void hmp_migrate_incoming(Monitor *mon, const QDict *qdict)
hmp_handle_error(mon, &err);
}
void hmp_migrate_recover(Monitor *mon, const QDict *qdict)
{
Error *err = NULL;
const char *uri = qdict_get_str(qdict, "uri");
qmp_migrate_recover(uri, &err);
hmp_handle_error(mon, &err);
}
void hmp_migrate_pause(Monitor *mon, const QDict *qdict)
{
Error *err = NULL;
qmp_migrate_pause(&err);
hmp_handle_error(mon, &err);
}
/* Kept for backwards compatibility */
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
{
@ -1929,10 +1948,12 @@ void hmp_migrate(Monitor *mon, const QDict *qdict)
bool detach = qdict_get_try_bool(qdict, "detach", false);
bool blk = qdict_get_try_bool(qdict, "blk", false);
bool inc = qdict_get_try_bool(qdict, "inc", false);
bool resume = qdict_get_try_bool(qdict, "resume", false);
const char *uri = qdict_get_str(qdict, "uri");
Error *err = NULL;
qmp_migrate(uri, !!blk, blk, !!inc, inc, false, false, &err);
qmp_migrate(uri, !!blk, blk, !!inc, inc,
false, false, true, resume, &err);
if (err) {
hmp_handle_error(mon, &err);
return;

2
hmp.h
View File

@ -68,6 +68,8 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict);
void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
void hmp_migrate_continue(Monitor *mon, const QDict *qdict);
void hmp_migrate_incoming(Monitor *mon, const QDict *qdict);
void hmp_migrate_recover(Monitor *mon, const QDict *qdict);
void hmp_migrate_pause(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);

2
include/migration/register.h
View File

@ -64,6 +64,8 @@ typedef struct SaveVMHandlers {
LoadStateHandler *load_state;
int (*load_setup)(QEMUFile *f, void *opaque);
int (*load_cleanup)(void *opaque);
/* Called when postcopy migration wants to resume from failure */
int (*resume_prepare)(MigrationState *s, void *opaque);
} SaveVMHandlers;
int register_savevm_live(DeviceState *dev,

12
migration/channel.c
View File

@ -71,11 +71,21 @@ void migration_channel_connect(MigrationState *s,
!object_dynamic_cast(OBJECT(ioc),
TYPE_QIO_CHANNEL_TLS)) {
migration_tls_channel_connect(s, ioc, hostname, &error);
if (!error) {
/* tls_channel_connect will call back to this
* function after the TLS handshake,
* so we mustn't call migrate_fd_connect until then
*/
return;
}
} else {
QEMUFile *f = qemu_fopen_channel_output(ioc);
qemu_mutex_lock(&s->qemu_file_lock);
s->to_dst_file = f;
qemu_mutex_unlock(&s->qemu_file_lock);
}
}
migrate_fd_connect(s, error);

9
migration/exec.c
View File

@ -65,9 +65,8 @@ void exec_start_incoming_migration(const char *command, Error **errp)
}
qio_channel_set_name(ioc, "migration-exec-incoming");
qio_channel_add_watch(ioc,
G_IO_IN,
exec_accept_incoming_migration,
NULL,
NULL);
qio_channel_add_watch_full(ioc, G_IO_IN,
exec_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
}

9
migration/fd.c
View File

@ -66,9 +66,8 @@ void fd_start_incoming_migration(const char *infd, Error **errp)
}
qio_channel_set_name(QIO_CHANNEL(ioc), "migration-fd-incoming");
qio_channel_add_watch(ioc,
G_IO_IN,
fd_accept_incoming_migration,
NULL,
NULL);
qio_channel_add_watch_full(ioc, G_IO_IN,
fd_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
}

559
migration/migration.c
View File

@ -95,6 +95,8 @@ enum mig_rp_message_type {
MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */
MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */
MIG_RP_MSG_MAX
};
@ -104,6 +106,7 @@ enum mig_rp_message_type {
dynamic creation of migration */
static MigrationState *current_migration;
static MigrationIncomingState *current_incoming;
static bool migration_object_check(MigrationState *ms, Error **errp);
static int migration_maybe_pause(MigrationState *s,
@ -119,6 +122,22 @@ void migration_object_init(void)
assert(!current_migration);
current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
/*
* Init the migrate incoming object as well no matter whether
* we'll use it or not.
*/
assert(!current_incoming);
current_incoming = g_new0(MigrationIncomingState, 1);
current_incoming->state = MIGRATION_STATUS_NONE;
current_incoming->postcopy_remote_fds =
g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD));
qemu_mutex_init(&current_incoming->rp_mutex);
qemu_event_init(&current_incoming->main_thread_load_event, false);
qemu_sem_init(&current_incoming->postcopy_pause_sem_dst, 0);
qemu_sem_init(&current_incoming->postcopy_pause_sem_fault, 0);
init_dirty_bitmap_incoming_migration();
if (!migration_object_check(current_migration, &err)) {
error_report_err(err);
exit(1);
@ -149,22 +168,8 @@ MigrationState *migrate_get_current(void)
MigrationIncomingState *migration_incoming_get_current(void)
{
static bool once;
static MigrationIncomingState mis_current;
if (!once) {
mis_current.state = MIGRATION_STATUS_NONE;
memset(&mis_current, 0, sizeof(MigrationIncomingState));
mis_current.postcopy_remote_fds = g_array_new(FALSE, TRUE,
sizeof(struct PostCopyFD));
qemu_mutex_init(&mis_current.rp_mutex);
qemu_event_init(&mis_current.main_thread_load_event, false);
init_dirty_bitmap_incoming_migration();
once = true;
}
return &mis_current;
assert(current_incoming);
return current_incoming;
}
void migration_incoming_state_destroy(void)
@ -430,7 +435,7 @@ static void migration_incoming_setup(QEMUFile *f)
qemu_file_set_blocking(f, false);
}
static void migration_incoming_process(void)
void migration_incoming_process(void)
{
Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
qemu_coroutine_enter(co);
@ -438,8 +443,34 @@ static void migration_incoming_process(void)
void migration_fd_process_incoming(QEMUFile *f)
{
migration_incoming_setup(f);
migration_incoming_process();
MigrationIncomingState *mis = migration_incoming_get_current();
if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
/* Resumed from a paused postcopy migration */
mis->from_src_file = f;
/* Postcopy has standalone thread to do vm load */
qemu_file_set_blocking(f, true);
/* Re-configure the return path */
mis->to_src_file = qemu_file_get_return_path(f);
migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
MIGRATION_STATUS_POSTCOPY_RECOVER);
/*
* Here, we only wake up the main loading thread (while the
* fault thread will still be waiting), so that we can receive
* commands from source now, and answer it if needed. The
* fault thread will be woken up afterwards until we are sure
* that source is ready to reply to page requests.
*/
qemu_sem_post(&mis->postcopy_pause_sem_dst);
} else {
/* New incoming migration */
migration_incoming_setup(f);
migration_incoming_process();
}
}
void migration_ioc_process_incoming(QIOChannel *ioc)
@ -448,9 +479,10 @@ void migration_ioc_process_incoming(QIOChannel *ioc)
if (!mis->from_src_file) {
QEMUFile *f = qemu_fopen_channel_input(ioc);
migration_fd_process_incoming(f);
migration_incoming_setup(f);
return;
}
/* We still only have a single channel. Nothing to do here yet */
multifd_recv_new_channel(ioc);
}
/**
@ -461,7 +493,11 @@ void migration_ioc_process_incoming(QIOChannel *ioc)
*/
bool migration_has_all_channels(void)
{
return true;
bool all_channels;
all_channels = multifd_recv_all_channels_created();
return all_channels;
}
/*
@ -491,6 +527,53 @@ void migrate_send_rp_pong(MigrationIncomingState *mis,
migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
}
void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
char *block_name)
{
char buf[512];
int len;
int64_t res;
/*
* First, we send the header part. It contains only the len of
* idstr, and the idstr itself.
*/
len = strlen(block_name);
buf[0] = len;
memcpy(buf + 1, block_name, len);
if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
__func__);
return;
}
migrate_send_rp_message(mis, MIG_RP_MSG_RECV_BITMAP, len + 1, buf);
/*
* Next, we dump the received bitmap to the stream.
*
* TODO: currently we are safe since we are the only one that is
* using the to_src_file handle (fault thread is still paused),
* and it's ok even not taking the mutex. However the best way is
* to take the lock before sending the message header, and release
* the lock after sending the bitmap.
*/
qemu_mutex_lock(&mis->rp_mutex);
res = ramblock_recv_bitmap_send(mis->to_src_file, block_name);
qemu_mutex_unlock(&mis->rp_mutex);
trace_migrate_send_rp_recv_bitmap(block_name, res);
}
void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value)
{
uint32_t buf;
buf = cpu_to_be32(value);
migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf);
}
MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
{
MigrationCapabilityStatusList *head = NULL;
@ -569,6 +652,8 @@ static bool migration_is_setup_or_active(int state)
switch (state) {
case MIGRATION_STATUS_ACTIVE:
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
case MIGRATION_STATUS_POSTCOPY_PAUSED:
case MIGRATION_STATUS_POSTCOPY_RECOVER:
case MIGRATION_STATUS_SETUP:
case MIGRATION_STATUS_PRE_SWITCHOVER:
case MIGRATION_STATUS_DEVICE:
@ -649,6 +734,8 @@ static void fill_source_migration_info(MigrationInfo *info)
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
case MIGRATION_STATUS_PRE_SWITCHOVER:
case MIGRATION_STATUS_DEVICE:
case MIGRATION_STATUS_POSTCOPY_PAUSED:
case MIGRATION_STATUS_POSTCOPY_RECOVER:
/* TODO add some postcopy stats */
info->has_status = true;
info->has_total_time = true;
@ -1147,6 +1234,7 @@ static void migrate_fd_cleanup(void *opaque)
if (s->to_dst_file) {
Error *local_err = NULL;
QEMUFile *tmp;
trace_migrate_fd_cleanup();
qemu_mutex_unlock_iothread();
@ -1159,8 +1247,15 @@ static void migrate_fd_cleanup(void *opaque)
if (multifd_save_cleanup(&local_err) != 0) {
error_report_err(local_err);
}
qemu_fclose(s->to_dst_file);
qemu_mutex_lock(&s->qemu_file_lock);
tmp = s->to_dst_file;
s->to_dst_file = NULL;
qemu_mutex_unlock(&s->qemu_file_lock);
/*
* Close the file handle without the lock to make sure the
* critical section won't block for long.
*/
qemu_fclose(tmp);
}
assert((s->state != MIGRATION_STATUS_ACTIVE) &&
@ -1388,6 +1483,59 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
once = false;
}
void qmp_migrate_recover(const char *uri, Error **errp)
{
MigrationIncomingState *mis = migration_incoming_get_current();
if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
error_setg(errp, "Migrate recover can only be run "
"when postcopy is paused.");
return;
}
if (atomic_cmpxchg(&mis->postcopy_recover_triggered,
false, true) == true) {
error_setg(errp, "Migrate recovery is triggered already");
return;
}
/*
* Note that this call will never start a real migration; it will
* only re-setup the migration stream and poke existing migration
* to continue using that newly established channel.
*/
qemu_start_incoming_migration(uri, errp);
}
void qmp_migrate_pause(Error **errp)
{
MigrationState *ms = migrate_get_current();
MigrationIncomingState *mis = migration_incoming_get_current();
int ret;
if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
/* Source side, during postcopy */
qemu_mutex_lock(&ms->qemu_file_lock);
ret = qemu_file_shutdown(ms->to_dst_file);
qemu_mutex_unlock(&ms->qemu_file_lock);
if (ret) {
error_setg(errp, "Failed to pause source migration");
}
return;
}
if (mis->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
ret = qemu_file_shutdown(mis->from_src_file);
if (ret) {
error_setg(errp, "Failed to pause destination migration");
}
return;
}
error_setg(errp, "migrate-pause is currently only supported "
"during postcopy-active state");
}
bool migration_is_blocked(Error **errp)
{
if (qemu_savevm_state_blocked(errp)) {
@ -1402,49 +1550,75 @@ bool migration_is_blocked(Error **errp)
return false;
}
void qmp_migrate(const char *uri, bool has_blk, bool blk,
bool has_inc, bool inc, bool has_detach, bool detach,
Error **errp)
/* Returns true if continue to migrate, or false if error detected */
static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
bool resume, Error **errp)
{
Error *local_err = NULL;
MigrationState *s = migrate_get_current();
const char *p;
if (resume) {
if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
error_setg(errp, "Cannot resume if there is no "
"paused migration");
return false;
}
/* This is a resume, skip init status */
return true;
}
if (migration_is_setup_or_active(s->state) ||
s->state == MIGRATION_STATUS_CANCELLING ||
s->state == MIGRATION_STATUS_COLO) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
return;
return false;
}
if (runstate_check(RUN_STATE_INMIGRATE)) {
error_setg(errp, "Guest is waiting for an incoming migration");
return;
return false;
}
if (migration_is_blocked(errp)) {
return;
return false;
}
if ((has_blk && blk) || (has_inc && inc)) {
if (blk || blk_inc) {
if (migrate_use_block() || migrate_use_block_incremental()) {
error_setg(errp, "Command options are incompatible with "
"current migration capabilities");
return;
return false;
}
migrate_set_block_enabled(true, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
return false;
}
s->must_remove_block_options = true;
}
if (has_inc && inc) {
if (blk_inc) {
migrate_set_block_incremental(s, true);
}
migrate_init(s);
return true;
}
void qmp_migrate(const char *uri, bool has_blk, bool blk,
bool has_inc, bool inc, bool has_detach, bool detach,
bool has_resume, bool resume, Error **errp)
{
Error *local_err = NULL;
MigrationState *s = migrate_get_current();
const char *p;
if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
has_resume && resume, errp)) {
/* Error detected, put into errp */
return;
}
if (strstart(uri, "tcp:", &p)) {
tcp_start_outgoing_migration(s, p, &local_err);
#ifdef CONFIG_RDMA
@ -1739,6 +1913,8 @@ static struct rp_cmd_args {
[MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
[MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
[MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
[MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
[MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" },
[MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
};
@ -1771,6 +1947,51 @@ static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
}
}
/* Return true to retry, false to quit */
static bool postcopy_pause_return_path_thread(MigrationState *s)
{
trace_postcopy_pause_return_path();
qemu_sem_wait(&s->postcopy_pause_rp_sem);
trace_postcopy_pause_return_path_continued();
return true;
}
static int migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name)
{
RAMBlock *block = qemu_ram_block_by_name(block_name);
if (!block) {
error_report("%s: invalid block name '%s'", __func__, block_name);
return -EINVAL;
}
/* Fetch the received bitmap and refresh the dirty bitmap */
return ram_dirty_bitmap_reload(s, block);
}
static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value)
{
trace_source_return_path_thread_resume_ack(value);
if (value != MIGRATION_RESUME_ACK_VALUE) {
error_report("%s: illegal resume_ack value %"PRIu32,
__func__, value);
return -1;
}
/* Now both sides are active. */
migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
MIGRATION_STATUS_POSTCOPY_ACTIVE);
/* Notify send thread that time to continue send pages */
qemu_sem_post(&s->rp_state.rp_sem);
return 0;
}
/*
* Handles messages sent on the return path towards the source VM
*
@ -1787,6 +2008,8 @@ static void *source_return_path_thread(void *opaque)
int res;
trace_source_return_path_thread_entry();
retry:
while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
migration_is_setup_or_active(ms->state)) {
trace_source_return_path_thread_loop_top();
@ -1874,23 +2097,61 @@ static void *source_return_path_thread(void *opaque)
migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
break;
case MIG_RP_MSG_RECV_BITMAP:
if (header_len < 1) {
error_report("%s: missing block name", __func__);
mark_source_rp_bad(ms);
goto out;
}
/* Format: len (1B) + idstr (<255B). This ends the idstr. */
buf[buf[0] + 1] = '\0';
if (migrate_handle_rp_recv_bitmap(ms, (char *)(buf + 1))) {
mark_source_rp_bad(ms);
goto out;
}
break;
case MIG_RP_MSG_RESUME_ACK:
tmp32 = ldl_be_p(buf);
if (migrate_handle_rp_resume_ack(ms, tmp32)) {
mark_source_rp_bad(ms);
goto out;
}
break;
default:
break;
}
}
if (qemu_file_get_error(rp)) {
out:
res = qemu_file_get_error(rp);
if (res) {
if (res == -EIO) {
/*
* Maybe there is something we can do: it looks like a
* network down issue, and we pause for a recovery.
*/
if (postcopy_pause_return_path_thread(ms)) {
/* Reload rp, reset the rest */
rp = ms->rp_state.from_dst_file;
ms->rp_state.error = false;
goto retry;
}
}
trace_source_return_path_thread_bad_end();
mark_source_rp_bad(ms);
}
trace_source_return_path_thread_end();
out:
ms->rp_state.from_dst_file = NULL;
qemu_fclose(rp);
return NULL;
}
static int open_return_path_on_source(MigrationState *ms)
static int open_return_path_on_source(MigrationState *ms,
bool create_thread)
{
ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
@ -1899,6 +2160,12 @@ static int open_return_path_on_source(MigrationState *ms)
}
trace_open_return_path_on_source();
if (!create_thread) {
/* We're done */
return 0;
}
qemu_thread_create(&ms->rp_state.rp_thread, "return path",
source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
@ -2238,6 +2505,156 @@ bool migrate_colo_enabled(void)
return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
}
typedef enum MigThrError {
/* No error detected */
MIG_THR_ERR_NONE = 0,
/* Detected error, but resumed successfully */
MIG_THR_ERR_RECOVERED = 1,
/* Detected fatal error, need to exit */
MIG_THR_ERR_FATAL = 2,
} MigThrError;
static int postcopy_resume_handshake(MigrationState *s)
{
qemu_savevm_send_postcopy_resume(s->to_dst_file);
while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
qemu_sem_wait(&s->rp_state.rp_sem);
}
if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
return 0;
}
return -1;
}
/* Return zero if success, or <0 for error */
static int postcopy_do_resume(MigrationState *s)
{
int ret;
/*
* Call all the resume_prepare() hooks, so that modules can be
* ready for the migration resume.
*/
ret = qemu_savevm_state_resume_prepare(s);
if (ret) {
error_report("%s: resume_prepare() failure detected: %d",
__func__, ret);
return ret;
}
/*
* Last handshake with destination on the resume (destination will
* switch to postcopy-active afterwards)
*/
ret = postcopy_resume_handshake(s);
if (ret) {
error_report("%s: handshake failed: %d", __func__, ret);
return ret;
}
return 0;
}
/*
* We don't return until we are in a safe state to continue current
* postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
* MIG_THR_ERR_FATAL if unrecovery failure happened.
*/
static MigThrError postcopy_pause(MigrationState *s)
{
assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
while (true) {
QEMUFile *file;
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_POSTCOPY_PAUSED);
/* Current channel is possibly broken. Release it. */
assert(s->to_dst_file);
qemu_mutex_lock(&s->qemu_file_lock);
file = s->to_dst_file;
s->to_dst_file = NULL;
qemu_mutex_unlock(&s->qemu_file_lock);
qemu_file_shutdown(file);
qemu_fclose(file);
error_report("Detected IO failure for postcopy. "
"Migration paused.");
/*
* We wait until things fixed up. Then someone will setup the
* status back for us.
*/
while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
qemu_sem_wait(&s->postcopy_pause_sem);
}
if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
/* Woken up by a recover procedure. Give it a shot */
/*
* Firstly, let's wake up the return path now, with a new
* return path channel.
*/
qemu_sem_post(&s->postcopy_pause_rp_sem);
/* Do the resume logic */
if (postcopy_do_resume(s) == 0) {
/* Let's continue! */
trace_postcopy_pause_continued();
return MIG_THR_ERR_RECOVERED;
} else {
/*
* Something wrong happened during the recovery, let's
* pause again. Pause is always better than throwing
* data away.
*/
continue;
}
} else {
/* This is not right... Time to quit. */
return MIG_THR_ERR_FATAL;
}
}
}
static MigThrError migration_detect_error(MigrationState *s)
{
int ret;
/* Try to detect any file errors */
ret = qemu_file_get_error(s->to_dst_file);
if (!ret) {
/* Everything is fine */
return MIG_THR_ERR_NONE;
}
if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) {
/*
* For postcopy, we allow the network to be down for a
* while. After that, it can be continued by a
* recovery phase.
*/
return postcopy_pause(s);
} else {
/*
* For precopy (or postcopy with error outside IO), we fail
* with no time.
*/
migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
trace_migration_thread_file_err();
/* Time to stop the migration, now. */
return MIG_THR_ERR_FATAL;
}
}
static void migration_calculate_complete(MigrationState *s)
{
uint64_t bytes = qemu_ftell(s->to_dst_file);
@ -2394,6 +2811,7 @@ static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
MigThrError thr_error;
rcu_register_thread();
@ -2443,13 +2861,22 @@ static void *migration_thread(void *opaque)
}
}
if (qemu_file_get_error(s->to_dst_file)) {
if (migration_is_setup_or_active(s->state)) {
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_FAILED);
}
trace_migration_thread_file_err();
/*
* Try to detect any kind of failures, and see whether we
* should stop the migration now.
*/
thr_error = migration_detect_error(s);
if (thr_error == MIG_THR_ERR_FATAL) {
/* Stop migration */
break;
} else if (thr_error == MIG_THR_ERR_RECOVERED) {
/*
* Just recovered from a e.g. network failure, reset all
* the local variables. This is important to avoid
* breaking transferred_bytes and bandwidth calculation
*/
s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
s->iteration_initial_bytes = 0;
}
current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
@ -2471,6 +2898,9 @@ static void *migration_thread(void *opaque)
void migrate_fd_connect(MigrationState *s, Error *error_in)
{
int64_t rate_limit;
bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
s->expected_downtime = s->parameters.downtime_limit;
s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
if (error_in) {
@ -2479,12 +2909,21 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
return;
}
qemu_file_set_blocking(s->to_dst_file, true);
qemu_file_set_rate_limit(s->to_dst_file,
s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
if (resume) {
/* This is a resumed migration */
rate_limit = INT64_MAX;
} else {
/* This is a fresh new migration */
rate_limit = s->parameters.max_bandwidth / XFER_LIMIT_RATIO;
s->expected_downtime = s->parameters.downtime_limit;
s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
/* Notify before starting migration thread */
notifier_list_notify(&migration_state_notifiers, s);
/* Notify before starting migration thread */
notifier_list_notify(&migration_state_notifiers, s);
}
qemu_file_set_rate_limit(s->to_dst_file, rate_limit);
qemu_file_set_blocking(s->to_dst_file, true);
/*
* Open the return path. For postcopy, it is used exclusively. For
@ -2492,15 +2931,22 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
* QEMU uses the return path.
*/
if (migrate_postcopy_ram() || migrate_use_return_path()) {
if (open_return_path_on_source(s)) {
if (open_return_path_on_source(s, !resume)) {
error_report("Unable to open return-path for postcopy");
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_FAILED);
migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
migrate_fd_cleanup(s);
return;
}
}
if (resume) {
/* Wakeup the main migration thread to do the recovery */
migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
MIGRATION_STATUS_POSTCOPY_RECOVER);
qemu_sem_post(&s->postcopy_pause_sem);
return;
}
if (multifd_save_setup() != 0) {
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_FAILED);
@ -2604,9 +3050,13 @@ static void migration_instance_finalize(Object *obj)
MigrationParameters *params = &ms->parameters;
qemu_mutex_destroy(&ms->error_mutex);
qemu_mutex_destroy(&ms->qemu_file_lock);
g_free(params->tls_hostname);
g_free(params->tls_creds);
qemu_sem_destroy(&ms->pause_sem);
qemu_sem_destroy(&ms->postcopy_pause_sem);
qemu_sem_destroy(&ms->postcopy_pause_rp_sem);
qemu_sem_destroy(&ms->rp_state.rp_sem);
error_free(ms->error);
}
@ -2636,6 +3086,11 @@ static void migration_instance_init(Object *obj)
params->has_x_multifd_channels = true;
params->has_x_multifd_page_count = true;
params->has_xbzrle_cache_size = true;
qemu_sem_init(&ms->postcopy_pause_sem, 0);
qemu_sem_init(&ms->postcopy_pause_rp_sem, 0);
qemu_sem_init(&ms->rp_state.rp_sem, 0);
qemu_mutex_init(&ms->qemu_file_lock);
}
/*

22
migration/migration.h
View File

@ -24,6 +24,8 @@
struct PostcopyBlocktimeContext;
#define MIGRATION_RESUME_ACK_VALUE (1)
/* State for the incoming migration */
struct MigrationIncomingState {
QEMUFile *from_src_file;
@ -73,6 +75,11 @@ struct MigrationIncomingState {
* live migration, to calculate vCPU block time
* */
struct PostcopyBlocktimeContext *blocktime_ctx;
/* notify PAUSED postcopy incoming migrations to try to continue */
bool postcopy_recover_triggered;
QemuSemaphore postcopy_pause_sem_dst;
QemuSemaphore postcopy_pause_sem_fault;
};
MigrationIncomingState *migration_incoming_get_current(void);
@ -107,6 +114,12 @@ struct MigrationState
QemuThread thread;
QEMUBH *cleanup_bh;
QEMUFile *to_dst_file;
/*
* Protects to_dst_file pointer. We need to make sure we won't
* yield or hang during the critical section, since this lock will
* be used in OOB command handler.
*/
QemuMutex qemu_file_lock;
/* bytes already send at the beggining of current interation */
uint64_t iteration_initial_bytes;
@ -129,6 +142,7 @@ struct MigrationState
QEMUFile *from_dst_file;
QemuThread rp_thread;
bool error;
QemuSemaphore rp_sem;
} rp_state;
double mbps;
@ -194,12 +208,17 @@ struct MigrationState
bool send_configuration;
/* Whether we send section footer during migration */
bool send_section_footer;
/* Needed by postcopy-pause state */
QemuSemaphore postcopy_pause_sem;
QemuSemaphore postcopy_pause_rp_sem;
};
void migrate_set_state(int *state, int old_state, int new_state);
void migration_fd_process_incoming(QEMUFile *f);
void migration_ioc_process_incoming(QIOChannel *ioc);
void migration_incoming_process(void);
bool migration_has_all_channels(void);
@ -251,6 +270,9 @@ void migrate_send_rp_pong(MigrationIncomingState *mis,
uint32_t value);
int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
ram_addr_t start, size_t len);
void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
char *block_name);
void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value);
void dirty_bitmap_mig_before_vm_start(void);
void init_dirty_bitmap_incoming_migration(void);

54
migration/postcopy-ram.c
View File

@ -830,6 +830,17 @@ static void mark_postcopy_blocktime_end(uintptr_t addr)
affected_cpu);
}
static bool postcopy_pause_fault_thread(MigrationIncomingState *mis)
{
trace_postcopy_pause_fault_thread();
qemu_sem_wait(&mis->postcopy_pause_sem_fault);
trace_postcopy_pause_fault_thread_continued();
return true;
}
/*
* Handle faults detected by the USERFAULT markings
*/
@ -880,6 +891,22 @@ static void *postcopy_ram_fault_thread(void *opaque)
break;
}
if (!mis->to_src_file) {
/*
* Possibly someone tells us that the return path is
* broken already using the event. We should hold until
* the channel is rebuilt.
*/
if (postcopy_pause_fault_thread(mis)) {
mis->last_rb = NULL;
/* Continue to read the userfaultfd */
} else {
error_report("%s: paused but don't allow to continue",
__func__);
break;
}
}
if (pfd[1].revents) {
uint64_t tmp64 = 0;
@ -942,18 +969,37 @@ static void *postcopy_ram_fault_thread(void *opaque)
(uintptr_t)(msg.arg.pagefault.address),
msg.arg.pagefault.feat.ptid, rb);
retry:
/*
* Send the request to the source - we want to request one
* of our host page sizes (which is >= TPS)
*/
if (rb != mis->last_rb) {
mis->last_rb = rb;
migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
rb_offset, qemu_ram_pagesize(rb));
ret = migrate_send_rp_req_pages(mis,
qemu_ram_get_idstr(rb),
rb_offset,
qemu_ram_pagesize(rb));
} else {
/* Save some space */
migrate_send_rp_req_pages(mis, NULL,
rb_offset, qemu_ram_pagesize(rb));
ret = migrate_send_rp_req_pages(mis,
NULL,
rb_offset,
qemu_ram_pagesize(rb));
}
if (ret) {
/* May be network failure, try to wait for recovery */
if (ret == -EIO && postcopy_pause_fault_thread(mis)) {
/* We got reconnected somehow, try to continue */
mis->last_rb = NULL;
goto retry;
} else {
/* This is a unavoidable fault */
error_report("%s: migrate_send_rp_req_pages() get %d",
__func__, ret);
break;
}
}
}

500
migration/ram.c
View File

@ -36,6 +36,7 @@
#include "xbzrle.h"
#include "ram.h"
#include "migration.h"
#include "socket.h"
#include "migration/register.h"
#include "migration/misc.h"
#include "qemu-file.h"
@ -51,6 +52,9 @@
#include "qemu/rcu_queue.h"
#include "migration/colo.h"
#include "migration/block.h"
#include "sysemu/sysemu.h"
#include "qemu/uuid.h"
#include "savevm.h"
/***********************************************************/
/* ram save/restore */
@ -187,6 +191,70 @@ void ramblock_recv_bitmap_set_range(RAMBlock *rb, void *host_addr,
nr);
}
#define RAMBLOCK_RECV_BITMAP_ENDING (0x0123456789abcdefULL)
/*
* Format: bitmap_size (8 bytes) + whole_bitmap (N bytes).
*
* Returns >0 if success with sent bytes, or <0 if error.
*/
int64_t ramblock_recv_bitmap_send(QEMUFile *file,
const char *block_name)
{
RAMBlock *block = qemu_ram_block_by_name(block_name);
unsigned long *le_bitmap, nbits;
uint64_t size;
if (!block) {
error_report("%s: invalid block name: %s", __func__, block_name);
return -1;
}
nbits = block->used_length >> TARGET_PAGE_BITS;
/*
* Make sure the tmp bitmap buffer is big enough, e.g., on 32bit
* machines we may need 4 more bytes for padding (see below
* comment). So extend it a bit before hand.
*/
le_bitmap = bitmap_new(nbits + BITS_PER_LONG);
/*
* Always use little endian when sending the bitmap. This is
* required that when source and destination VMs are not using the
* same endianess. (Note: big endian won't work.)
*/
bitmap_to_le(le_bitmap, block->receivedmap, nbits);
/* Size of the bitmap, in bytes */
size = nbits / 8;
/*
* size is always aligned to 8 bytes for 64bit machines, but it
* may not be true for 32bit machines. We need this padding to
* make sure the migration can survive even between 32bit and
* 64bit machines.
*/
size = ROUND_UP(size, 8);
qemu_put_be64(file, size);
qemu_put_buffer(file, (const uint8_t *)le_bitmap, size);
/*
* Mark as an end, in case the middle part is screwed up due to
* some "misterious" reason.
*/
qemu_put_be64(file, RAMBLOCK_RECV_BITMAP_ENDING);
qemu_fflush(file);
free(le_bitmap);
if (qemu_file_get_error(file)) {
return qemu_file_get_error(file);
}
return size + sizeof(size);
}
/*
* An outstanding page request, on the source, having been received
* and queued
@ -432,15 +500,117 @@ exit:
/* Multiple fd's */
struct MultiFDSendParams {
#define MULTIFD_MAGIC 0x11223344U
#define MULTIFD_VERSION 1
typedef struct {
uint32_t magic;
uint32_t version;
unsigned char uuid[16]; /* QemuUUID */
uint8_t id;
} __attribute__((packed)) MultiFDInit_t;
typedef struct {
/* this fields are not changed once the thread is created */
/* channel number */
uint8_t id;
/* channel thread name */
char *name;
/* channel thread id */
QemuThread thread;
/* communication channel */
QIOChannel *c;
/* sem where to wait for more work */
QemuSemaphore sem;
/* this mutex protects the following parameters */
QemuMutex mutex;
/* is this channel thread running */
bool running;
/* should this thread finish */
bool quit;
};
typedef struct MultiFDSendParams MultiFDSendParams;
} MultiFDSendParams;
typedef struct {
/* this fields are not changed once the thread is created */
/* channel number */
uint8_t id;
/* channel thread name */
char *name;
/* channel thread id */
QemuThread thread;
/* communication channel */
QIOChannel *c;
/* sem where to wait for more work */
QemuSemaphore sem;
/* this mutex protects the following parameters */
QemuMutex mutex;
/* is this channel thread running */
bool running;
/* should this thread finish */
bool quit;
} MultiFDRecvParams;
static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
{
MultiFDInit_t msg;
int ret;
msg.magic = cpu_to_be32(MULTIFD_MAGIC);
msg.version = cpu_to_be32(MULTIFD_VERSION);
msg.id = p->id;
memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid));
ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp);
if (ret != 0) {
return -1;
}
return 0;
}
static int multifd_recv_initial_packet(QIOChannel *c, Error **errp)
{
MultiFDInit_t msg;
int ret;
ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp);
if (ret != 0) {
return -1;
}
be32_to_cpus(&msg.magic);
be32_to_cpus(&msg.version);
if (msg.magic != MULTIFD_MAGIC) {
error_setg(errp, "multifd: received packet magic %x "
"expected %x", msg.magic, MULTIFD_MAGIC);
return -1;
}
if (msg.version != MULTIFD_VERSION) {
error_setg(errp, "multifd: received packet version %d "
"expected %d", msg.version, MULTIFD_VERSION);
return -1;
}
if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) {
char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid);
char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid);
error_setg(errp, "multifd: received uuid '%s' and expected "
"uuid '%s' for channel %hhd", msg_uuid, uuid, msg.id);
g_free(uuid);
g_free(msg_uuid);
return -1;
}
if (msg.id > migrate_multifd_channels()) {
error_setg(errp, "multifd: received channel version %d "
"expected %d", msg.version, MULTIFD_VERSION);
return -1;
}
return msg.id;
}
struct {
MultiFDSendParams *params;
@ -448,11 +618,23 @@ struct {
int count;
} *multifd_send_state;
static void terminate_multifd_send_threads(Error *errp)
static void multifd_send_terminate_threads(Error *err)
{
int i;
for (i = 0; i < multifd_send_state->count; i++) {
if (err) {
MigrationState *s = migrate_get_current();
migrate_set_error(s, err);
if (s->state == MIGRATION_STATUS_SETUP ||
s->state == MIGRATION_STATUS_PRE_SWITCHOVER ||
s->state == MIGRATION_STATUS_DEVICE ||
s->state == MIGRATION_STATUS_ACTIVE) {
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_FAILED);
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
qemu_mutex_lock(&p->mutex);
@ -470,11 +652,15 @@ int multifd_save_cleanup(Error **errp)
if (!migrate_use_multifd()) {
return 0;
}
terminate_multifd_send_threads(NULL);
for (i = 0; i < multifd_send_state->count; i++) {
multifd_send_terminate_threads(NULL);
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
qemu_thread_join(&p->thread);
if (p->running) {
qemu_thread_join(&p->thread);
}
socket_send_channel_destroy(p->c);
p->c = NULL;
qemu_mutex_destroy(&p->mutex);
qemu_sem_destroy(&p->sem);
g_free(p->name);
@ -490,6 +676,11 @@ int multifd_save_cleanup(Error **errp)
static void *multifd_send_thread(void *opaque)
{
MultiFDSendParams *p = opaque;
Error *local_err = NULL;
if (multifd_send_initial_packet(p, &local_err) < 0) {
goto out;
}
while (true) {
qemu_mutex_lock(&p->mutex);
@ -501,9 +692,39 @@ static void *multifd_send_thread(void *opaque)
qemu_sem_wait(&p->sem);
}
out:
if (local_err) {
multifd_send_terminate_threads(local_err);
}
qemu_mutex_lock(&p->mutex);
p->running = false;
qemu_mutex_unlock(&p->mutex);
return NULL;
}
static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque)
{
MultiFDSendParams *p = opaque;
QIOChannel *sioc = QIO_CHANNEL(qio_task_get_source(task));
Error *local_err = NULL;
if (qio_task_propagate_error(task, &local_err)) {
if (multifd_save_cleanup(&local_err) != 0) {
migrate_set_error(migrate_get_current(), local_err);
}
} else {
p->c = QIO_CHANNEL(sioc);
qio_channel_set_delay(p->c, false);
p->running = true;
qemu_thread_create(&p->thread, p->name, multifd_send_thread, p,
QEMU_THREAD_JOINABLE);
atomic_inc(&multifd_send_state->count);
}
}
int multifd_save_setup(void)
{
int thread_count;
@ -515,7 +736,7 @@ int multifd_save_setup(void)
thread_count = migrate_multifd_channels();
multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
multifd_send_state->params = g_new0(MultiFDSendParams, thread_count);
multifd_send_state->count = 0;
atomic_set(&multifd_send_state->count, 0);
for (i = 0; i < thread_count; i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
@ -524,35 +745,32 @@ int multifd_save_setup(void)
p->quit = false;
p->id = i;
p->name = g_strdup_printf("multifdsend_%d", i);
qemu_thread_create(&p->thread, p->name, multifd_send_thread, p,
QEMU_THREAD_JOINABLE);
multifd_send_state->count++;
socket_send_channel_create(multifd_new_send_channel_async, p);
}
return 0;
}
struct MultiFDRecvParams {
uint8_t id;
char *name;
QemuThread thread;
QemuSemaphore sem;
QemuMutex mutex;
bool quit;
};
typedef struct MultiFDRecvParams MultiFDRecvParams;
struct {
MultiFDRecvParams *params;
/* number of created threads */
int count;
} *multifd_recv_state;
static void terminate_multifd_recv_threads(Error *errp)
static void multifd_recv_terminate_threads(Error *err)
{
int i;
for (i = 0; i < multifd_recv_state->count; i++) {
if (err) {
MigrationState *s = migrate_get_current();
migrate_set_error(s, err);
if (s->state == MIGRATION_STATUS_SETUP ||
s->state == MIGRATION_STATUS_ACTIVE) {
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_FAILED);
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
qemu_mutex_lock(&p->mutex);
@ -570,11 +788,15 @@ int multifd_load_cleanup(Error **errp)
if (!migrate_use_multifd()) {
return 0;
}
terminate_multifd_recv_threads(NULL);
for (i = 0; i < multifd_recv_state->count; i++) {
multifd_recv_terminate_threads(NULL);
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
qemu_thread_join(&p->thread);
if (p->running) {
qemu_thread_join(&p->thread);
}
object_unref(OBJECT(p->c));
p->c = NULL;
qemu_mutex_destroy(&p->mutex);
qemu_sem_destroy(&p->sem);
g_free(p->name);
@ -602,6 +824,10 @@ static void *multifd_recv_thread(void *opaque)
qemu_sem_wait(&p->sem);
}
qemu_mutex_lock(&p->mutex);
p->running = false;
qemu_mutex_unlock(&p->mutex);
return NULL;
}
@ -616,7 +842,7 @@ int multifd_load_setup(void)
thread_count = migrate_multifd_channels();
multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state));
multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count);
multifd_recv_state->count = 0;
atomic_set(&multifd_recv_state->count, 0);
for (i = 0; i < thread_count; i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
@ -625,13 +851,52 @@ int multifd_load_setup(void)
p->quit = false;
p->id = i;
p->name = g_strdup_printf("multifdrecv_%d", i);
qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p,
QEMU_THREAD_JOINABLE);
multifd_recv_state->count++;
}
return 0;
}
bool multifd_recv_all_channels_created(void)
{
int thread_count = migrate_multifd_channels();
if (!migrate_use_multifd()) {
return true;
}
return thread_count == atomic_read(&multifd_recv_state->count);
}
void multifd_recv_new_channel(QIOChannel *ioc)
{
MultiFDRecvParams *p;
Error *local_err = NULL;
int id;
id = multifd_recv_initial_packet(ioc, &local_err);
if (id < 0) {
multifd_recv_terminate_threads(local_err);
return;
}
p = &multifd_recv_state->params[id];
if (p->c != NULL) {
error_setg(&local_err, "multifd: received id '%d' already setup'",
id);
multifd_recv_terminate_threads(local_err);
return;
}
p->c = ioc;
object_ref(OBJECT(ioc));
p->running = true;
qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p,
QEMU_THREAD_JOINABLE);
atomic_inc(&multifd_recv_state->count);
if (multifd_recv_state->count == migrate_multifd_channels()) {
migration_incoming_process();
}
}
/**
* save_page_header: write page header to wire
*
@ -1490,7 +1755,7 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
* CPU resource.
*/
if (block == rs->last_sent_block && save_page_use_compression(rs)) {
res = compress_page_with_multi_thread(rs, block, offset);
return compress_page_with_multi_thread(rs, block, offset);
}
return ram_save_page(rs, pss, last_stage);
@ -2226,6 +2491,41 @@ static int ram_init_all(RAMState **rsp)
return 0;
}
static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out)
{
RAMBlock *block;
uint64_t pages = 0;
/*
* Postcopy is not using xbzrle/compression, so no need for that.
* Also, since source are already halted, we don't need to care
* about dirty page logging as well.
*/
RAMBLOCK_FOREACH(block) {
pages += bitmap_count_one(block->bmap,
block->used_length >> TARGET_PAGE_BITS);
}
/* This may not be aligned with current bitmaps. Recalculate. */
rs->migration_dirty_pages = pages;
rs->last_seen_block = NULL;
rs->last_sent_block = NULL;
rs->last_page = 0;
rs->last_version = ram_list.version;
/*
* Disable the bulk stage, otherwise we'll resend the whole RAM no
* matter what we have sent.
*/
rs->ram_bulk_stage = false;
/* Update RAMState cache of output QEMUFile */
rs->f = out;
trace_ram_state_resume_prepare(pages);
}
/*
* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
@ -3100,6 +3400,139 @@ static bool ram_has_postcopy(void *opaque)
return migrate_postcopy_ram();
}
/* Sync all the dirty bitmap with destination VM. */
static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs)
{
RAMBlock *block;
QEMUFile *file = s->to_dst_file;
int ramblock_count = 0;
trace_ram_dirty_bitmap_sync_start();
RAMBLOCK_FOREACH(block) {
qemu_savevm_send_recv_bitmap(file, block->idstr);
trace_ram_dirty_bitmap_request(block->idstr);
ramblock_count++;
}
trace_ram_dirty_bitmap_sync_wait();
/* Wait until all the ramblocks' dirty bitmap synced */
while (ramblock_count--) {
qemu_sem_wait(&s->rp_state.rp_sem);
}
trace_ram_dirty_bitmap_sync_complete();
return 0;
}
static void ram_dirty_bitmap_reload_notify(MigrationState *s)
{
qemu_sem_post(&s->rp_state.rp_sem);
}
/*
* Read the received bitmap, revert it as the initial dirty bitmap.
* This is only used when the postcopy migration is paused but wants
* to resume from a middle point.
*/
int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block)
{
int ret = -EINVAL;
QEMUFile *file = s->rp_state.from_dst_file;
unsigned long *le_bitmap, nbits = block->used_length >> TARGET_PAGE_BITS;
uint64_t local_size = nbits / 8;
uint64_t size, end_mark;
trace_ram_dirty_bitmap_reload_begin(block->idstr);
if (s->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
error_report("%s: incorrect state %s", __func__,
MigrationStatus_str(s->state));
return -EINVAL;
}
/*
* Note: see comments in ramblock_recv_bitmap_send() on why we
* need the endianess convertion, and the paddings.
*/
local_size = ROUND_UP(local_size, 8);
/* Add paddings */
le_bitmap = bitmap_new(nbits + BITS_PER_LONG);
size = qemu_get_be64(file);
/* The size of the bitmap should match with our ramblock */
if (size != local_size) {
error_report("%s: ramblock '%s' bitmap size mismatch "
"(0x%"PRIx64" != 0x%"PRIx64")", __func__,
block->idstr, size, local_size);
ret = -EINVAL;
goto out;
}
size = qemu_get_buffer(file, (uint8_t *)le_bitmap, local_size);
end_mark = qemu_get_be64(file);
ret = qemu_file_get_error(file);
if (ret || size != local_size) {
error_report("%s: read bitmap failed for ramblock '%s': %d"
" (size 0x%"PRIx64", got: 0x%"PRIx64")",
__func__, block->idstr, ret, local_size, size);
ret = -EIO;
goto out;
}
if (end_mark != RAMBLOCK_RECV_BITMAP_ENDING) {
error_report("%s: ramblock '%s' end mark incorrect: 0x%"PRIu64,
__func__, block->idstr, end_mark);
ret = -EINVAL;
goto out;
}
/*
* Endianess convertion. We are during postcopy (though paused).
* The dirty bitmap won't change. We can directly modify it.
*/
bitmap_from_le(block->bmap, le_bitmap, nbits);
/*
* What we received is "received bitmap". Revert it as the initial
* dirty bitmap for this ramblock.
*/
bitmap_complement(block->bmap, block->bmap, nbits);
trace_ram_dirty_bitmap_reload_complete(block->idstr);
/*
* We succeeded to sync bitmap for current ramblock. If this is
* the last one to sync, we need to notify the main send thread.
*/
ram_dirty_bitmap_reload_notify(s);
ret = 0;
out:
free(le_bitmap);
return ret;
}
static int ram_resume_prepare(MigrationState *s, void *opaque)
{
RAMState *rs = *(RAMState **)opaque;
int ret;
ret = ram_dirty_bitmap_sync_all(s, rs);
if (ret) {
return ret;
}
ram_state_resume_prepare(rs, s->to_dst_file);
return 0;
}
static SaveVMHandlers savevm_ram_handlers = {
.save_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
@ -3111,6 +3544,7 @@ static SaveVMHandlers savevm_ram_handlers = {
.save_cleanup = ram_save_cleanup,
.load_setup = ram_load_setup,
.load_cleanup = ram_load_cleanup,
.resume_prepare = ram_resume_prepare,
};
void ram_mig_init(void)

6
migration/ram.h
View File

@ -32,6 +32,7 @@
#include "qemu-common.h"
#include "qapi/qapi-types-migration.h"
#include "exec/cpu-common.h"
#include "io/channel.h"
extern MigrationStats ram_counters;
extern XBZRLECacheStats xbzrle_counters;
@ -44,6 +45,8 @@ int multifd_save_setup(void);
int multifd_save_cleanup(Error **errp);
int multifd_load_setup(void);
int multifd_load_cleanup(Error **errp);
bool multifd_recv_all_channels_created(void);
void multifd_recv_new_channel(QIOChannel *ioc);
uint64_t ram_pagesize_summary(void);
int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
@ -63,5 +66,8 @@ int ramblock_recv_bitmap_test(RAMBlock *rb, void *host_addr);
bool ramblock_recv_bitmap_test_byte_offset(RAMBlock *rb, uint64_t byte_offset);
void ramblock_recv_bitmap_set(RAMBlock *rb, void *host_addr);
void ramblock_recv_bitmap_set_range(RAMBlock *rb, void *host_addr, size_t nr);
int64_t ramblock_recv_bitmap_send(QEMUFile *file,
const char *block_name);
int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *rb);
#endif

7
migration/rdma.c
View File

@ -708,6 +708,9 @@ static int rdma_delete_block(RDMAContext *rdma, RDMALocalBlock *block)
memcpy(local->block + block->index, old + (block->index + 1),
sizeof(RDMALocalBlock) *
(local->nb_blocks - (block->index + 1)));
for (x = block->index; x < local->nb_blocks - 1; x++) {
local->block[x].index--;
}
}
} else {
assert(block == local->block);
@ -3246,6 +3249,10 @@ static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque)
qsort(rdma->local_ram_blocks.block,
rdma->local_ram_blocks.nb_blocks,
sizeof(RDMALocalBlock), dest_ram_sort_func);
for (i = 0; i < local->nb_blocks; i++) {
local->block[i].index = i;
}
if (rdma->pin_all) {
ret = qemu_rdma_reg_whole_ram_blocks(rdma);
if (ret) {

191
migration/savevm.c
View File

@ -80,7 +80,9 @@ enum qemu_vm_cmd {
MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
were previously sent during
precopy but are dirty. */
MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */
MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */
MIG_CMD_MAX
};
@ -97,7 +99,9 @@ static struct mig_cmd_args {
[MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
[MIG_CMD_POSTCOPY_RAM_DISCARD] = {
.len = -1, .name = "POSTCOPY_RAM_DISCARD" },
[MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" },
[MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
[MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
[MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
};
@ -956,6 +960,25 @@ void qemu_savevm_send_postcopy_run(QEMUFile *f)
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
}
void qemu_savevm_send_postcopy_resume(QEMUFile *f)
{
trace_savevm_send_postcopy_resume();
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL);
}
void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name)
{
size_t len;
char buf[256];
trace_savevm_send_recv_bitmap(block_name);
buf[0] = len = strlen(block_name);
memcpy(buf + 1, block_name, len);
qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf);
}
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@ -1008,6 +1031,31 @@ void qemu_savevm_state_setup(QEMUFile *f)
}
}
int qemu_savevm_state_resume_prepare(MigrationState *s)
{
SaveStateEntry *se;
int ret;
trace_savevm_state_resume_prepare();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->resume_prepare) {
continue;
}
if (se->ops && se->ops->is_active) {
if (!se->ops->is_active(se->opaque)) {
continue;
}
}
ret = se->ops->resume_prepare(s, se->opaque);
if (ret < 0) {
return ret;
}
}
return 0;
}
/*
* this function has three return values:
* negative: there was one error, and we have -errno.
@ -1564,8 +1612,8 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
*/
static void *postcopy_ram_listen_thread(void *opaque)
{
QEMUFile *f = opaque;
MigrationIncomingState *mis = migration_incoming_get_current();
QEMUFile *f = mis->from_src_file;
int load_res;
migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
@ -1579,6 +1627,14 @@ static void *postcopy_ram_listen_thread(void *opaque)
*/
qemu_file_set_blocking(f, true);
load_res = qemu_loadvm_state_main(f, mis);
/*
* This is tricky, but, mis->from_src_file can change after it
* returns, when postcopy recovery happened. In the future, we may
* want a wrapper for the QEMUFile handle.
*/
f = mis->from_src_file;
/* And non-blocking again so we don't block in any cleanup */
qemu_file_set_blocking(f, false);
@ -1668,7 +1724,7 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
/* Start up the listening thread and wait for it to signal ready */
qemu_sem_init(&mis->listen_thread_sem, 0);
qemu_thread_create(&mis->listen_thread, "postcopy/listen",
postcopy_ram_listen_thread, mis->from_src_file,
postcopy_ram_listen_thread, NULL,
QEMU_THREAD_DETACHED);
qemu_sem_wait(&mis->listen_thread_sem);
qemu_sem_destroy(&mis->listen_thread_sem);
@ -1745,6 +1801,31 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
return LOADVM_QUIT;
}
static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
{
if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
error_report("%s: illegal resume received", __func__);
/* Don't fail the load, only for this. */
return 0;
}
/*
* This means source VM is ready to resume the postcopy migration.
* It's time to switch state and release the fault thread to
* continue service page faults.
*/
migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
MIGRATION_STATUS_POSTCOPY_ACTIVE);
qemu_sem_post(&mis->postcopy_pause_sem_fault);
trace_loadvm_postcopy_handle_resume();
/* Tell source that "we are ready" */
migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE);
return 0;
}
/**
* Immediately following this command is a blob of data containing an embedded
* chunk of migration stream; read it and load it.
@ -1793,6 +1874,49 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
return ret;
}
/*
* Handle request that source requests for recved_bitmap on
* destination. Payload format:
*
* len (1 byte) + ramblock_name (<255 bytes)
*/
static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
uint16_t len)
{
QEMUFile *file = mis->from_src_file;
RAMBlock *rb;
char block_name[256];
size_t cnt;
cnt = qemu_get_counted_string(file, block_name);
if (!cnt) {
error_report("%s: failed to read block name", __func__);
return -EINVAL;
}
/* Validate before using the data */
if (qemu_file_get_error(file)) {
return qemu_file_get_error(file);
}
if (len != cnt + 1) {
error_report("%s: invalid payload length (%d)", __func__, len);
return -EINVAL;
}
rb = qemu_ram_block_by_name(block_name);
if (!rb) {
error_report("%s: block '%s' not found", __func__, block_name);
return -EINVAL;
}
migrate_send_rp_recv_bitmap(mis, block_name);
trace_loadvm_handle_recv_bitmap(block_name);
return 0;
}
/*
* Process an incoming 'QEMU_VM_COMMAND'
* 0 just a normal return
@ -1866,6 +1990,12 @@ static int loadvm_process_command(QEMUFile *f)
case MIG_CMD_POSTCOPY_RAM_DISCARD:
return loadvm_postcopy_ram_handle_discard(mis, len);
case MIG_CMD_POSTCOPY_RESUME:
return loadvm_postcopy_handle_resume(mis);
case MIG_CMD_RECV_BITMAP:
return loadvm_handle_recv_bitmap(mis, len);
}
return 0;
@ -2055,11 +2185,50 @@ void qemu_loadvm_state_cleanup(void)
}
}
/* Return true if we should continue the migration, or false. */
static bool postcopy_pause_incoming(MigrationIncomingState *mis)
{
trace_postcopy_pause_incoming();
/* Clear the triggered bit to allow one recovery */
mis->postcopy_recover_triggered = false;
migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
MIGRATION_STATUS_POSTCOPY_PAUSED);
assert(mis->from_src_file);
qemu_file_shutdown(mis->from_src_file);
qemu_fclose(mis->from_src_file);
mis->from_src_file = NULL;
assert(mis->to_src_file);
qemu_file_shutdown(mis->to_src_file);
qemu_mutex_lock(&mis->rp_mutex);
qemu_fclose(mis->to_src_file);
mis->to_src_file = NULL;
qemu_mutex_unlock(&mis->rp_mutex);
/* Notify the fault thread for the invalidated file handle */
postcopy_fault_thread_notify(mis);
error_report("Detected IO failure for postcopy. "
"Migration paused.");
while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
qemu_sem_wait(&mis->postcopy_pause_sem_dst);
}
trace_postcopy_pause_incoming_continued();
return true;
}
static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
{
uint8_t section_type;
int ret = 0;
retry:
while (true) {
section_type = qemu_get_byte(f);
@ -2104,6 +2273,24 @@ static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
out:
if (ret < 0) {
qemu_file_set_error(f, ret);
/*
* Detect whether it is:
*
* 1. postcopy running (after receiving all device data, which
* must be in POSTCOPY_INCOMING_RUNNING state. Note that
* POSTCOPY_INCOMING_LISTENING is still not enough, it's
* still receiving device states).
* 2. network failure (-EIO)
*
* If so, we try to wait for a recovery.
*/
if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING &&
ret == -EIO && postcopy_pause_incoming(mis)) {
/* Reset f to point to the newly created channel */
f = mis->from_src_file;
goto retry;
}
}
return ret;
}

3
migration/savevm.h
View File

@ -31,6 +31,7 @@
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_setup(QEMUFile *f);
int qemu_savevm_state_resume_prepare(MigrationState *s);
void qemu_savevm_state_header(QEMUFile *f);
int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy);
void qemu_savevm_state_cleanup(void);
@ -47,6 +48,8 @@ int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len);
void qemu_savevm_send_postcopy_advise(QEMUFile *f);
void qemu_savevm_send_postcopy_listen(QEMUFile *f);
void qemu_savevm_send_postcopy_run(QEMUFile *f);
void qemu_savevm_send_postcopy_resume(QEMUFile *f);
void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name);
void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
uint16_t len,

39
migration/socket.c
View File

@ -28,6 +28,28 @@
#include "trace.h"
struct SocketOutgoingArgs {
SocketAddress *saddr;
} outgoing_args;
void socket_send_channel_create(QIOTaskFunc f, void *data)
{
QIOChannelSocket *sioc = qio_channel_socket_new();
qio_channel_socket_connect_async(sioc, outgoing_args.saddr,
f, data, NULL, NULL);
}
int socket_send_channel_destroy(QIOChannel *send)
{
/* Remove channel */
object_unref(OBJECT(send));
if (outgoing_args.saddr) {
qapi_free_SocketAddress(outgoing_args.saddr);
outgoing_args.saddr = NULL;
}
return 0;
}
static SocketAddress *tcp_build_address(const char *host_port, Error **errp)
{
SocketAddress *saddr;
@ -95,6 +117,11 @@ static void socket_start_outgoing_migration(MigrationState *s,
struct SocketConnectData *data = g_new0(struct SocketConnectData, 1);
data->s = s;
/* in case previous migration leaked it */
qapi_free_SocketAddress(outgoing_args.saddr);
outgoing_args.saddr = saddr;
if (saddr->type == SOCKET_ADDRESS_TYPE_INET) {
data->hostname = g_strdup(saddr->u.inet.host);
}
@ -106,7 +133,6 @@ static void socket_start_outgoing_migration(MigrationState *s,
data,
socket_connect_data_free,
NULL);
qapi_free_SocketAddress(saddr);
}
void tcp_start_outgoing_migration(MigrationState *s,
@ -144,6 +170,10 @@ static void socket_accept_incoming_migration(QIONetListener *listener,
qio_net_listener_disconnect(listener);
object_unref(OBJECT(listener));
if (!migrate_use_multifd()) {
migration_incoming_process();
}
}
}
@ -160,9 +190,10 @@ static void socket_start_incoming_migration(SocketAddress *saddr,
return;
}
qio_net_listener_set_client_func(listener,
socket_accept_incoming_migration,
NULL, NULL);
qio_net_listener_set_client_func_full(listener,
socket_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
}
void tcp_start_incoming_migration(const char *host_port, Error **errp)

7
migration/socket.h
View File

@ -16,6 +16,13 @@
#ifndef QEMU_MIGRATION_SOCKET_H
#define QEMU_MIGRATION_SOCKET_H
#include "io/channel.h"
#include "io/task.h"
void socket_send_channel_create(QIOTaskFunc f, void *data);
int socket_send_channel_destroy(QIOChannel *send);
void tcp_start_incoming_migration(const char *host_port, Error **errp);
void tcp_start_outgoing_migration(MigrationState *s, const char *host_port,

21
migration/trace-events
View File

@ -12,11 +12,13 @@ loadvm_state_cleanup(void) ""
loadvm_handle_cmd_packaged(unsigned int length) "%u"
loadvm_handle_cmd_packaged_main(int ret) "%d"
loadvm_handle_cmd_packaged_received(int ret) "%d"
loadvm_handle_recv_bitmap(char *s) "%s"
loadvm_postcopy_handle_advise(void) ""
loadvm_postcopy_handle_listen(void) ""
loadvm_postcopy_handle_run(void) ""
loadvm_postcopy_handle_run_cpu_sync(void) ""
loadvm_postcopy_handle_run_vmstart(void) ""
loadvm_postcopy_handle_resume(void) ""
loadvm_postcopy_ram_handle_discard(void) ""
loadvm_postcopy_ram_handle_discard_end(void) ""
loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud"
@ -34,7 +36,10 @@ savevm_send_open_return_path(void) ""
savevm_send_ping(uint32_t val) "0x%x"
savevm_send_postcopy_listen(void) ""
savevm_send_postcopy_run(void) ""
savevm_send_postcopy_resume(void) ""
savevm_send_recv_bitmap(char *name) "%s"
savevm_state_setup(void) ""
savevm_state_resume_prepare(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""
savevm_state_cleanup(void) ""
@ -77,6 +82,13 @@ ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
ram_postcopy_send_discard_bitmap(void) ""
ram_save_page(const char *rbname, uint64_t offset, void *host) "%s: offset: 0x%" PRIx64 " host: %p"
ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: 0x%zx len: 0x%zx"
ram_dirty_bitmap_request(char *str) "%s"
ram_dirty_bitmap_reload_begin(char *str) "%s"
ram_dirty_bitmap_reload_complete(char *str) "%s"
ram_dirty_bitmap_sync_start(void) ""
ram_dirty_bitmap_sync_wait(void) ""
ram_dirty_bitmap_sync_complete(void) ""
ram_state_resume_prepare(uint64_t v) "%" PRId64
# migration/migration.c
await_return_path_close_on_source_close(void) ""
@ -88,6 +100,7 @@ migrate_fd_cancel(void) ""
migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len) "in %s at 0x%zx len 0x%zx"
migrate_pending(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
migrate_send_rp_recv_bitmap(char *name, int64_t size) "block '%s' size 0x%"PRIi64
migration_completion_file_err(void) ""
migration_completion_postcopy_end(void) ""
migration_completion_postcopy_end_after_complete(void) ""
@ -99,6 +112,13 @@ migration_thread_setup_complete(void) ""
open_return_path_on_source(void) ""
open_return_path_on_source_continue(void) ""
postcopy_start(void) ""
postcopy_pause_return_path(void) ""
postcopy_pause_return_path_continued(void) ""
postcopy_pause_fault_thread(void) ""
postcopy_pause_fault_thread_continued(void) ""
postcopy_pause_continued(void) ""
postcopy_pause_incoming(void) ""
postcopy_pause_incoming_continued(void) ""
postcopy_start_set_run(void) ""
source_return_path_thread_bad_end(void) ""
source_return_path_thread_end(void) ""
@ -106,6 +126,7 @@ source_return_path_thread_entry(void) ""
source_return_path_thread_loop_top(void) ""
source_return_path_thread_pong(uint32_t val) "0x%x"
source_return_path_thread_shut(uint32_t val) "0x%x"
source_return_path_thread_resume_ack(uint32_t v) "%"PRIu32
migrate_global_state_post_load(const char *state) "loaded state: %s"
migrate_global_state_pre_save(const char *state) "saved state: %s"
migration_thread_low_pending(uint64_t pending) "%" PRIu64

57
qapi/migration.json
View File

@ -89,6 +89,10 @@
#
# @postcopy-active: like active, but now in postcopy mode. (since 2.5)
#
# @postcopy-paused: during postcopy but paused. (since 2.13)
#
# @postcopy-recover: trying to recover from a paused postcopy. (since 2.13)
#
# @completed: migration is finished.
#
# @failed: some error occurred during migration process.
@ -106,7 +110,8 @@
##
{ 'enum': 'MigrationStatus',
'data': [ 'none', 'setup', 'cancelling', 'cancelled',
'active', 'postcopy-active', 'completed', 'failed', 'colo',
'active', 'postcopy-active', 'postcopy-paused',
'postcopy-recover', 'completed', 'failed', 'colo',
'pre-switchover', 'device' ] }
##
@ -157,11 +162,13 @@
# error strings. (Since 2.7)
#
# @postcopy-blocktime: total time when all vCPU were blocked during postcopy
# live migration (Since 2.13)
# live migration. This is only present when the postcopy-blocktime
# migration capability is enabled. (Since 2.13)
#
# @postcopy-vcpu-blocktime: list of the postcopy blocktime per vCPU (Since 2.13)
# @postcopy-vcpu-blocktime: list of the postcopy blocktime per vCPU. This is
# only present when the postcopy-blocktime migration capability
# is enabled. (Since 2.13)
#
#
# Since: 0.14.0
##
@ -363,7 +370,6 @@
#
# @x-multifd: Use more than one fd for migration (since 2.11)
#
#
# @dirty-bitmaps: If enabled, QEMU will migrate named dirty bitmaps.
# (since 2.12)
#
@ -1028,6 +1034,8 @@
# @detach: this argument exists only for compatibility reasons and
# is ignored by QEMU
#
# @resume: resume one paused migration, default "off". (since 2.13)
#
# Returns: nothing on success
#
# Since: 0.14.0
@ -1049,7 +1057,8 @@
#
##
{ 'command': 'migrate',
'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool', '*detach': 'bool' } }
'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool',
'*detach': 'bool', '*resume': 'bool' } }
##
# @migrate-incoming:
@ -1183,3 +1192,39 @@
# Since: 2.9
##
{ 'command': 'xen-colo-do-checkpoint' }
##
# @migrate-recover:
#
# Provide a recovery migration stream URI.
#
# @uri: the URI to be used for the recovery of migration stream.
#
# Returns: nothing.
#
# Example:
#
# -> { "execute": "migrate-recover",
# "arguments": { "uri": "tcp:192.168.1.200:12345" } }
# <- { "return": {} }
#
# Since: 2.13
##
{ 'command': 'migrate-recover', 'data': { 'uri': 'str' },
'allow-oob': true }
##
# @migrate-pause:
#
# Pause a migration. Currently it only supports postcopy.
#
# Returns: nothing.
#
# Example:
#
# -> { "execute": "migrate-pause" }
# <- { "return": {} }
#
# Since: 2.13
##
{ 'command': 'migrate-pause', 'allow-oob': true }

85
tests/migration-test.c
View File

@ -19,9 +19,6 @@
#include "qemu/sockets.h"
#include "chardev/char.h"
#include "sysemu/sysemu.h"
#include "hw/nvram/chrp_nvram.h"
#define MIN_NVRAM_SIZE 8192 /* from spapr_nvram.c */
const unsigned start_address = 1024 * 1024;
const unsigned end_address = 100 * 1024 * 1024;
@ -92,36 +89,6 @@ static void init_bootfile_x86(const char *bootpath)
fclose(bootfile);
}
static void init_bootfile_ppc(const char *bootpath)
{
FILE *bootfile;
char buf[MIN_NVRAM_SIZE];
ChrpNvramPartHdr *header = (ChrpNvramPartHdr *)buf;
memset(buf, 0, MIN_NVRAM_SIZE);
/* Create a "common" partition in nvram to store boot-command property */
header->signature = CHRP_NVPART_SYSTEM;
memcpy(header->name, "common", 6);
chrp_nvram_finish_partition(header, MIN_NVRAM_SIZE);
/* FW_MAX_SIZE is 4MB, but slof.bin is only 900KB,
* so let's modify memory between 1MB and 100MB
* to do like PC bootsector
*/
sprintf(buf + 16,
"boot-command=hex .\" _\" begin %x %x do i c@ 1 + i c! 1000 +loop "
".\" B\" 0 until", end_address, start_address);
/* Write partition to the NVRAM file */
bootfile = fopen(bootpath, "wb");
g_assert_cmpint(fwrite(buf, MIN_NVRAM_SIZE, 1, bootfile), ==, 1);
fclose(bootfile);
}
/*
* Wait for some output in the serial output file,
* we get an 'A' followed by an endless string of 'B's
@ -422,12 +389,14 @@ static void test_migrate_start(QTestState **from, QTestState **to,
if (access("/sys/module/kvm_hv", F_OK)) {
accel = "tcg";
}
init_bootfile_ppc(bootpath);
cmd_src = g_strdup_printf("-machine accel=%s -m 256M"
" -name source,debug-threads=on"
" -serial file:%s/src_serial"
" -drive file=%s,if=pflash,format=raw",
accel, tmpfs, bootpath);
" -prom-env '"
"boot-command=hex .\" _\" begin %x %x "
"do i c@ 1 + i c! 1000 +loop .\" B\" 0 "
"until'", accel, tmpfs, end_address,
start_address);
cmd_dst = g_strdup_printf("-machine accel=%s -m 256M"
" -name target,debug-threads=on"
" -serial file:%s/dest_serial"
@ -536,7 +505,7 @@ static void test_deprecated(void)
qtest_quit(from);
}
static void test_migrate(void)
static void test_postcopy(void)
{
char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
QTestState *from, *to;
@ -611,6 +580,45 @@ static void test_baddest(void)
test_migrate_end(from, to, false);
}
static void test_precopy_unix(void)
{
char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
QTestState *from, *to;
test_migrate_start(&from, &to, uri, false);
/* We want to pick a speed slow enough that the test completes
* quickly, but that it doesn't complete precopy even on a slow
* machine, so also set the downtime.
*/
/* 1 ms should make it not converge*/
migrate_set_parameter(from, "downtime-limit", "1");
/* 1GB/s */
migrate_set_parameter(from, "max-bandwidth", "1000000000");
/* Wait for the first serial output from the source */
wait_for_serial("src_serial");
migrate(from, uri);
wait_for_migration_pass(from);
/* 300 ms should converge */
migrate_set_parameter(from, "downtime-limit", "300");
if (!got_stop) {
qtest_qmp_eventwait(from, "STOP");
}
qtest_qmp_eventwait(to, "RESUME");
wait_for_serial("dest_serial");
wait_for_migration_complete(from);
test_migrate_end(from, to, true);
g_free(uri);
}
int main(int argc, char **argv)
{
char template[] = "/tmp/migration-test-XXXXXX";
@ -630,9 +638,10 @@ int main(int argc, char **argv)
module_call_init(MODULE_INIT_QOM);
qtest_add_func("/migration/postcopy/unix", test_migrate);
qtest_add_func("/migration/postcopy/unix", test_postcopy);
qtest_add_func("/migration/deprecated", test_deprecated);
qtest_add_func("/migration/bad_dest", test_baddest);
qtest_add_func("/migration/precopy/unix", test_precopy_unix);
ret = g_test_run();