The no_migrate save state flag is currently only checked in the
last phase of migration.  This means that we potentially waste
a lot of time and bandwidth with the live state handlers before
we ever check the no_migrate flags.  The error message printed
when we catch a non-migratable device doesn't get printed for
a detached migration.  And, no_migrate does nothing to prevent
an incoming migration to a target that includes a non-migratable
device.  This attempts to fix all of these.

One notable difference in behavior is that an outgoing migration
now checks for non-migratable devices before ever connecting to
the target system.  This means the target will remain listening
rather than exit from failure.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

There's no need to flush requests after vmstop
as vmstop does it for us automatically now.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Tested-by: NJason Wang <jasowang@redhat.com>

I'd like to disable bandwidth limit or make it very high,
Use int64_t all over to make values >= 4g work.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Tested-by: NJason Wang <jasowang@redhat.com>

Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Nmalc <av1474@comtv.ru>

Compiling with GCC 4.6.0 20100925 produced warnings like:
/src/qemu/net/tap-win32.c: In function 'tap_win32_open':
/src/qemu/net/tap-win32.c:582:12: error: variable 'hThread' set but not used [-Werror=unused-but-set-variable]

Fix by removing the unused variables.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Fix this warning:
  CC    savevm.o
/src/qemu/savevm.c: In function `do_savevm':
/src/qemu/savevm.c:1900: warning: passing arg 1 of `localtime_r' from incompatible pointer type

It looks like on OpenBSD the type of tv_sec in struct timeval is still
'long' instead of time_t as in most other OS. Fix by adding a cast.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

When savevm is run without a name, the name stays blank and the snapshot is
saved anyway.

The new behavior is when savevm is run without parameters a name will be
created automaticaly, so the snapshot is accessible to the user without needing
the id when loadvm is run.

(qemu) savevm
(qemu) info snapshots
ID        TAG                 VM SIZE                DATE       VM CLOCK
1         vm-20100728134640      978K 2010-07-28 13:46:40   00:00:08.603

We use a name with the format 'vm-YYYYMMDDHHMMSS'.

This is a first step to hide the internal id, because I don't see a reason to
expose this kind of internals to the user.
Signed-off-by: NMiguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The output generated by 'info snapshots' shows only snapshots that exist on the
block device that saves the VM state. This output can cause an user to
erroneously try to load an snapshot that is not available on all block devices.

$ qemu-img snapshot -l xxtest.qcow2
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
1                                1.5M 2010-07-26 16:51:52   00:00:08.599
2                                1.5M 2010-07-26 16:51:53   00:00:09.719
3                                1.5M 2010-07-26 17:26:49   00:00:13.245
4                                1.5M 2010-07-26 19:01:00   00:00:46.763

$ qemu-img snapshot -l xxtest2.qcow2
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
3                                   0 2010-07-26 17:26:49   00:00:13.245
4                                   0 2010-07-26 19:01:00   00:00:46.763

Current output:
$ qemu -hda xxtest.qcow2 -hdb xxtest2.qcow2 -monitor stdio -vnc :0
QEMU 0.12.4 monitor - type 'help' for more information
(qemu) info snapshots
Snapshot devices: ide0-hd0
Snapshot list (from ide0-hd0):
ID        TAG                 VM SIZE                DATE       VM CLOCK
1                                1.5M 2010-07-26 16:51:52   00:00:08.599
2                                1.5M 2010-07-26 16:51:53   00:00:09.719
3                                1.5M 2010-07-26 17:26:49   00:00:13.245
4                                1.5M 2010-07-26 19:01:00   00:00:46.763

Snapshots 1 and 2 do not exist on xxtest2.qcow, but they are displayed anyway.

This patch sumarizes the output to only show fully available snapshots.

New output:
(qemu) info snapshots
ID        TAG                 VM SIZE                DATE       VM CLOCK
3                                1.5M 2010-07-26 17:26:49   00:00:13.245
4                                1.5M 2010-07-26 19:01:00   00:00:46.763
Signed-off-by: NMiguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

A non-migratable device should be removed before migration and re-added after.
Signed-off-by: NCam Macdonell <cam@cs.ualberta.ca>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This patch improves the resilience of the load_vmstate() function, doing
further and better ordered tests.

In load_vmstate(), if there is any error on bdrv_snapshot_goto(), except if the
error is on VM state device, load_vmstate() will return zero and the VM will be
started with major corruption chances.

The current process:
- test if there is any writable device without snapshot support
    - if exists return -error
- get the device that saves the VM state, possible return -error but unlikely
because it was tested earlier
- flush I/O
- run bdrv_snapshot_goto() on devices
    - if fails, give an warning and goes to the next (not good!)
    - if fails on the VM state device, return zero (not good!)
- check if the requested snapshot exists on the device that saves the VM state
and the state is not zero
    - if fails return -error
- open the file with the VM state
    - if fails return -error
- load the VM state
    - if fails return -error
- return zero

New behavior:
- get the device that saves the VM state
    - if fails return -error
- check if the requested snapshot exists on the device that saves the VM state
and the state is not zero
    - if fails return -error
- test if there is any writable device without snapshot support
    - if exists return -error
- test if the devices with snapshot support have the requested snapshot
    - if anyone fails, return -error
- flush I/O
- run snapshot_goto() on devices
    - if anyone fails, return -error
- open the file with the VM state
    - if fails return -error
- load the VM state
    - if fails return -error
- return zero

do_loadvm must not call vm_start if any error has occurred in load_vmstate.
Signed-off-by: NMiguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Forgot to check for and free these.
Found-by: NZachary Amsden <zamsden@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

This commit adds subsections for each device section.
Subsections is the way to handle information that don't need to be sent
to de destination of a migration because its values are not needed.  It is
the way to handle optional information.  Notice that only the source can
decide if the information is optional or not.  The destination needs to
understand all subsections that it receives to have a sucessful load.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

For callers that pass a device we can traverse up the qdev tree and
make use of the BusInfo.get_dev_path information for creating unique
savevm id strings.  This avoids needing to rely on the instance number,
which can cause problems with device initialization order and hotplug.

For compatibility, we also store away the old id string and instance
so we can accept migrations from VMs as we add new get_dev_path
implementations.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

When available, we'd like to be able to access the DeviceState
when registering a savevm.  For buses with a get_dev_path()
function, this will allow us to create more unique savevm
id strings.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

savevm.c keeps a pointer to the snapshot block device.  If you manage
to get that device deleted, the pointer dangles, and the next snapshot
operation will crash & burn.  Unplugging a guest device that uses it
does the trick:

    $ MALLOC_PERTURB_=234 qemu-system-x86_64 [...]
    QEMU 0.12.50 monitor - type 'help' for more information
    (qemu) info snapshots
    No available block device supports snapshots
    (qemu) drive_add auto if=none,file=tmp.qcow2
    OK
    (qemu) device_add usb-storage,id=foo,drive=none1
    (qemu) info snapshots
    Snapshot devices: none1
    Snapshot list (from none1):
    ID        TAG                 VM SIZE                DATE       VM CLOCK
    (qemu) device_del foo
    (qemu) info snapshots
    Snapshot devices:
    Segmentation fault (core dumped)

Move management of that pointer to block.c, and zap it when the device
it points becomes unusable.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We find snapshots by iterating over the list of drives defined with
drive_init().  This misses host block devices defined by other means.
Such means don't exist now, but will be introduced later in this
series.

Iterate over all host block devices instead, with bdrv_next().
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Both bdrv_can_snapshot() and bdrv_has_snapshot() does not work as advertized.

First issue: Their names implies different porpouses, but they do the same thing
and have exactly the same code. Maybe copied and pasted and forgotten?
bdrv_has_snapshot() is called in various places for actually checking if there
is snapshots or not.

Second issue: the way bdrv_can_snapshot() verifies if a block driver supports or
not snapshots does not catch all cases. E.g.: a raw image.

So when do_savevm() is called, first thing it does is to set a global
BlockDriverState to save the VM memory state calling get_bs_snapshots().

static BlockDriverState *get_bs_snapshots(void)
{
    BlockDriverState *bs;
    DriveInfo *dinfo;

    if (bs_snapshots)
        return bs_snapshots;
    QTAILQ_FOREACH(dinfo, &drives, next) {
        bs = dinfo->bdrv;
        if (bdrv_can_snapshot(bs))
            goto ok;
    }
    return NULL;
 ok:
    bs_snapshots = bs;
    return bs;
}

bdrv_can_snapshot() may return a BlockDriverState that does not support
snapshots and do_savevm() goes on.

Later on in do_savevm(), we find:

    QTAILQ_FOREACH(dinfo, &drives, next) {
        bs1 = dinfo->bdrv;
        if (bdrv_has_snapshot(bs1)) {
            /* Write VM state size only to the image that contains the state */
            sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
            ret = bdrv_snapshot_create(bs1, sn);
            if (ret < 0) {
                monitor_printf(mon, "Error while creating snapshot on '%s'\n",
                               bdrv_get_device_name(bs1));
            }
        }
    }

bdrv_has_snapshot(bs1) is not checking if the device does support or has
snapshots as explained above. Only in bdrv_snapshot_create() the device is
actually checked for snapshot support.

So, in cases where the first device supports snapshots, and the second does not,
the snapshot on the first will happen anyways. I believe this is not a good
behavior. It should be an all or nothing process.

This patch addresses these issues by making bdrv_can_snapshot() actually do
what it must do and enforces better tests to avoid errors in the middle of
do_savevm(). bdrv_has_snapshot() is removed and replaced by bdrv_can_snapshot()
where appropriate.

bdrv_can_snapshot() was moved from savevm.c to block.c. It makes more sense to me.

The loadvm_state() function was updated too to enforce that when loading a VM at
least all writable devices must support snapshots too.
Signed-off-by: NMiguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Anything that moves hundreds of lines out of vl.c can't be all bad.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch makes sure that if the exec: process exits with a non-zero return
status, we treat the migration as failed.

This fixes https://bugs.launchpad.net/qemu/+bug/391879Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Some legacy users (mostly PC devices) of vmstate_register manage
instance IDs on their own, and that unfortunately in a way that is
incompatible with automatically generated ones. This so far prevents
switching those users to vmstates that are registered by qdev.

To establish a migration path, this patch introduces the concept of
alias IDs. They can be passed to an extended vmstate registration
service, and qdev provides a set service to be used during device init.
find_se will consider the alias in addition to the default ID. We can
then start generating the default ID automatically and writing it on
vmsave, thus converting that format without breaking support for upward
migration.

The user is required specify the highest vmstate version for which the
alias is required. Once this version falls behind the minimum required
for a specific vmstate, an assertion triggers to motivate cleaning up
the obsolete alias.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

No device makes use of it anymore.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

The packet(s) sent out after migration are supposed to be RAPR type of
packets. If they are supposed to go anywhere useful, the RAPR ethernet
identifier needs to be fix.

Also see http://www.iana.org/assignments/ethernet-numbers for 0x8035 for
RARP.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

error_report() terminates the message with a newline.  Strip it it
from its arguments.

This fixes a few error messages lacking a newline:
net_handle_fd_param()'s "No file descriptor named %s found", and
tap_open()'s "vnet_hdr=1 requested, but no kernel support for
IFF_VNET_HDR available" (all three versions).

There's one place that passes arguments without newlines
intentionally: load_vmstate().  Fix it up.

A monitor may not even exist.

Change load_vmstate() to use qemu_error() instead of monitor_printf().
Parameter mon is now unused, remove it.

Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

This grand cleanup drops all reset and vmsave/load related
synchronization points in favor of four(!) generic hooks:

- cpu_synchronize_all_states in qemu_savevm_state_complete
  (initial sync from kernel before vmsave)
- cpu_synchronize_all_post_init in qemu_loadvm_state
  (writeback after vmload)
- cpu_synchronize_all_post_init in main after machine init
- cpu_synchronize_all_post_reset in qemu_system_reset
  (writeback after system reset)

These writeback points + the existing one of VCPU exec after
cpu_synchronize_state map on three levels of writeback:

- KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run)
- KVM_PUT_RESET_STATE   (on synchronous system reset, all VCPUs stopped)
- KVM_PUT_FULL_STATE    (on init or vmload, all VCPUs stopped as well)

This level is passed to the arch-specific VCPU state writing function
that will decide which concrete substates need to be written. That way,
no writer of load, save or reset functions that interact with in-kernel
KVM states will ever have to worry about synchronization again. That
also means that a lot of reasons for races, segfaults and deadlocks are
eliminated.

cpu_synchronize_state remains untouched, just as Anthony suggested. We
continue to need it before reading or writing of VCPU states that are
also tracked by in-kernel KVM subsystems.

Consequently, this patch removes many cpu_synchronize_state calls that
are now redundant, just like remaining explicit register syncs.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

savevm without id or tag segfaults in:

(gdb) bt
#0  0x00007f600a83bf8a in __strcmp_sse42 () from /lib64/libc.so.6
#1  0x00000000004745b6 in bdrv_snapshot_find (bs=<value optimized out>,
    sn_info=0x7fff996be280, name=0x0) at savevm.c:1631
#2  0x0000000000475c80 in del_existing_snapshots (name=<value optimized out>,
    mon=<value optimized out>) at savevm.c:1654
#3  do_savevm (name=<value optimized out>, mon=<value optimized out>)
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

  CC    savevm.o
cc1: warnings being treated as errors
savevm.c: In function 'file_put_buffer':
savevm.c:342: error: ignoring return value of 'fwrite', declared with attribute warn_unused_result
make: *** [savevm.o] Error 1
Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

The effect of this patch with current block migration is that its stage
2, ie. the first full walk-through of the block devices will be
performed completely before RAM migration starts. This ensures that
continuously changing RAM pages are not re-synchronized all the time
while block migration is not completed.

Future versions of block migration which will respect the specified
downtime will generate a different pattern: After RAM migration has
started as well, block migration may also continue to inject dirty
blocks into the RAM stream once it detects that the number of pending
blocks would extend the downtime unacceptably.

Note that all this relies on the current registration order: block
before RAM migration.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

In order to allow proper progress reporting to the monitor that
initiated the migration, forward the monitor reference through the
migration layer down to SaveLiveStateHandler.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Introduce qemu_savevm_state_cancel and inject a stage -1 to cancel a
live migration. This gives the involved subsystems a chance to clean up
dynamically allocated resources. Namely, the block migration layer can
now free its device descriptors and pending blocks.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

When the size that we want to transmit is in another field, but in an
unit different that bytes
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Support for buffer that are pointed by a pointer (i.e. not embedded)
where the size that we want to use is a field in the state.
We also need a new place to store where to start in the middle of the
buffer, as now it is a pointer, not the offset of the 1st field.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Seeking on vmstate save/load does not work if the underlying file is a
stream. We could try to make all QEMUFile* forward-seek-aware, but first
attempts in this direction indicated that it's saner to convert the few
qemu_fseek-on-vmstates users to plain reads/writes.

This fixes various subtle vmstate corruptions where unused fields were
involved.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Now that we have a way to iterate NICs.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

This patch introduces block migration called during live migration. Block
are being copied to the destination in an async way. First the code will
transfer the whole disk and then transfer all dirty blocks accumulted during
the migration.
Still need to improve transition from the iterative phase of migration to the
end phase. For now transition will take place when all blocks transfered once,
all the dirty blocks will be transfered during the end phase (guest is
suspended).

Changes from v4:
- Global variabels moved to a global state structure allocated dynamically.
- Minor coding style issues.
- Poll block.c for tracking of dirty blocks instead of manage it here.
Signed-off-by: NLiran Schour <lirans@il.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

When creating a snapshot we can run into the situation that the first disk
doesn't have a snapshot, but the second one does have one with the same name as
the new snapshot.

In this case, qemu doesn't recognize that there is a snapshot to be
overwritten, so it starts to save the new snapshot and errors out later when it
tries to snapshot the second image. With this patch, snapshots on secondary
images are overwritten just like on the first image.
Reported-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

commit b04c4134
broke incoming migration.  After talking with Gleb, code was intended
to be the way is in this fix.  This fixes migration here.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>