postcopy: helper for waking shared

Provide a helper to send a 'wake' request on a userfaultfd for
a shared process.
The address in the clients address space is specified together
with the RAMBlock i

postcopy: helper for waking shared

Provide a helper to send a 'wake' request on a userfaultfd for
a shared process.
The address in the clients address space is specified together
with the RAMBlock it was resolved to.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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postcopy-ram: add a stub for postcopy_request_shared_page

This fixes the build on systems without userfaultfd.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vhost+postcopy: Helper to send requests to source for shared pages

Provide a helper to be used by shared waker functions to request
shared pages from the source.
The last_rb pointer is moved into th

vhost+postcopy: Helper to send requests to source for shared pages

Provide a helper to be used by shared waker functions to request
shared pages from the source.
The last_rb pointer is moved into the incoming state since this
helper can update it as well as the main fault thread function.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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postcopy: Allow registering of fd handler

Allow other userfaultfd's to be registered into the fault thread
so that handlers for shared memory can get responses.

Signed-off-by: Dr. David Alan Gilber

postcopy: Allow registering of fd handler

Allow other userfaultfd's to be registered into the fault thread
so that handlers for shared memory can get responses.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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postcopy: Add notifier chain

Add a notifier chain for postcopy with a 'reason' flag
and an opportunity for a notifier member to return an error.

Call it when enabling postcopy.

This will initially

postcopy: Add notifier chain

Add a notifier chain for postcopy with a 'reason' flag
and an opportunity for a notifier member to return an error.

Call it when enabling postcopy.

This will initially used to enable devices to declare they're unable
to postcopy and later to notify of devices of stages within postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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postcopy: use UFFDIO_ZEROPAGE only when available

Use a flag on the RAMBlock to state whether it has the
UFFDIO_ZEROPAGE capability, use it when it's available.

This allows the use of postcopy on t

postcopy: use UFFDIO_ZEROPAGE only when available

Use a flag on the RAMBlock to state whether it has the
UFFDIO_ZEROPAGE capability, use it when it's available.

This allows the use of postcopy on tmpfs as well as hugepage
backed files.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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migration: provide postcopy_fault_thread_notify()

A general helper to notify the fault thread.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>

migration: provide postcopy_fault_thread_notify()

A general helper to notify the fault thread.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180208103132.28452-4-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

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migration: reuse mis->userfault_quit_fd

It was only used for quitting the page fault thread before. Let it be
something more useful - now we can use it to notify a "wake" for the
page fault thread (

migration: reuse mis->userfault_quit_fd

It was only used for quitting the page fault thread before. Let it be
something more useful - now we can use it to notify a "wake" for the
page fault thread (for any reason), and it only means "quit" if the
fault_thread_quit is set.

Since we changed what it does, renaming it to userfault_event_fd.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180208103132.28452-3-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

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migration: Revert postcopy-blocktime commit set

This reverts commits
ca6011c migration: add postcopy total blocktime into query-migrate
5f32dc8 migration: add blocktime calculation into migration-te

migration: Revert postcopy-blocktime commit set

This reverts commits
ca6011c migration: add postcopy total blocktime into query-migrate
5f32dc8 migration: add blocktime calculation into migration-test
2f7dae9 migration: postcopy_blocktime documentation
3be98be migration: calculate vCPU blocktime on dst side
01a87f0 migration: add postcopy blocktime ctx into MigrationIncomingState
31bf06a migration: introduce postcopy-blocktime capability

as they don't build on ppc32 due to trying to do atomic accesses
on types that are larger than the host pointer type.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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migration: add postcopy total blocktime into query-migrate

Postcopy total blocktime is available on destination side only.
But query-migrate was possible only for source. This patch
adds ability to

migration: add postcopy total blocktime into query-migrate

Postcopy total blocktime is available on destination side only.
But query-migrate was possible only for source. This patch
adds ability to call query-migrate on destination.
To be able to see postcopy blocktime, need to request postcopy-blocktime
capability.

The query-migrate command will show following sample result:
{"return":
"postcopy-vcpu-blocktime": [115, 100],
"status": "completed",
"postcopy-blocktime": 100
}}

postcopy_vcpu_blocktime contains list, where the first item is the first
vCPU in QEMU.

This patch has a drawback, it combines states of incoming and
outgoing migration. Ongoing migration state will overwrite incoming
state. Looks like better to separate query-migrate for incoming and
outgoing migration or add parameter to indicate type of migration.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: calculate vCPU blocktime on dst side

This patch provides blocktime calculation per vCPU,
as a summary and as a overlapped value for all vCPUs.

This approach was suggested by Peter Xu, as

migration: calculate vCPU blocktime on dst side

This patch provides blocktime calculation per vCPU,
as a summary and as a overlapped value for all vCPUs.

This approach was suggested by Peter Xu, as an improvements of
previous approch where QEMU kept tree with faulted page address and cpus bitmask
in it. Now QEMU is keeping array with faulted page address as value and vCPU
as index. It helps to find proper vCPU at UFFD_COPY time. Also it keeps
list for blocktime per vCPU (could be traced with page_fault_addr)

Blocktime will not calculated if postcopy_blocktime field of
MigrationIncomingState wasn't initialized.

Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: add postcopy blocktime ctx into MigrationIncomingState

This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID, in
case this feature is provided by kernel.

PostcopyBlocktimeCo

migration: add postcopy blocktime ctx into MigrationIncomingState

This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID, in
case this feature is provided by kernel.

PostcopyBlocktimeContext is encapsulated inside postcopy-ram.c,
due to it being a postcopy-only feature.
Also it defines PostcopyBlocktimeContext's instance live time.
Information from PostcopyBlocktimeContext instance will be provided
much after postcopy migration end, instance of PostcopyBlocktimeContext
will live till QEMU exit, but part of it (vcpu_addr,
page_fault_vcpu_time) used only during calculation, will be released
when postcopy ended or failed.

To enable postcopy blocktime calculation on destination, need to
request proper compatibility (Patch for documentation will be at the
tail of the patch set).

As an example following command enable that capability, assume QEMU was
started with
-chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
option to control it

[root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
{\"execute\": \"migrate-set-capabilities\" , \"arguments\": {
\"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock

Or just with HMP
(qemu) migrate_set_capability postcopy-blocktime on

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: add bitmap for received page

This patch adds ability to track down already received
pages, it's necessary for calculation vCPU block time in
postcopy migration feature, and for recovery a

migration: add bitmap for received page

This patch adds ability to track down already received
pages, it's necessary for calculation vCPU block time in
postcopy migration feature, and for recovery after
postcopy migration failure.

Also it's necessary to solve shared memory issue in
postcopy livemigration. Information about received pages
will be transferred to the software virtual bridge
(e.g. OVS-VSWITCHD), to avoid fallocate (unmap) for
already received pages. fallocate syscall is required for
remmaped shared memory, due to remmaping itself blocks
ioctl(UFFDIO_COPY, ioctl in this case will end with EEXIT
error (struct page is exists after remmap).

Bitmap is placed into RAMBlock as another postcopy/precopy
related bitmaps.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: introduce qemu_ufd_copy_ioctl helper

Just for placing auxilary operations inside helper,
auxilary operations like: track received pages,
notify about copying operation in futher patches.

migration: introduce qemu_ufd_copy_ioctl helper

Just for placing auxilary operations inside helper,
auxilary operations like: track received pages,
notify about copying operation in futher patches.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: postcopy_place_page factoring out

Need to mark copied pages as closer as possible to the place where it
tracks down. That will be necessary in futher patch.

Reviewed-by: Dr. David Alan G

migration: postcopy_place_page factoring out

Need to mark copied pages as closer as possible to the place where it
tracks down. That will be necessary in futher patch.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: split ufd_version_check onto receive/request features part

This modification is necessary for userfault fd features which are
required to be requested from userspace.
UFFD_FEATURE_THREAD_

migration: split ufd_version_check onto receive/request features part

This modification is necessary for userfault fd features which are
required to be requested from userspace.
UFFD_FEATURE_THREAD_ID is a one of such "on demand" feature, which will
be introduced in the next patch.

QEMU have to use separate userfault file descriptor, due to
userfault context has internal state, and after first call of
ioctl UFFD_API it changes its state to UFFD_STATE_RUNNING (in case of
success), but kernel while handling ioctl UFFD_API expects UFFD_STATE_WAIT_API.
So only one ioctl with UFFD_API is possible per ufd.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: fix hardcoded function name in error report

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.p

migration: fix hardcoded function name in error report

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: pass MigrationIncomingState* into migration check functions

That tiny refactoring is necessary to be able to set
UFFD_FEATURE_THREAD_ID while requesting features, and then
to create downt

migration: pass MigrationIncomingState* into migration check functions

That tiny refactoring is necessary to be able to set
UFFD_FEATURE_THREAD_ID while requesting features, and then
to create downtime context in case when kernel supports it.

Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: Remove unneeded includes

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>

migration: Move migration.h to migration/

Nothing uses it outside of migration.h

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by

migration: Move migration.h to migration/

Nothing uses it outside of migration.h

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>

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migration: Export ram.c functions in its own file

All functions are internal except for ram_mig_init(). Create
migration/misc.h for this kind of functions.

Signed-off-by: Juan Quintela <quintela@r

migration: Export ram.c functions in its own file

All functions are internal except for ram_mig_init(). Create
migration/misc.h for this kind of functions.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

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migration: Split qemu-file.h

Split the file into public and internal interfaces. I have to rename
the external one because we can't have two include files with the same
name in the same directory.

migration: Split qemu-file.h

Split the file into public and internal interfaces. I have to rename
the external one because we can't have two include files with the same
name in the same directory. Build system gets confused. The only
exported functions are the ones that handle basic types.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

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migration: shut src return path unconditionally

We were do the shutting off only for postcopy. Now we do this as long as
the source return path is there.

Moving the cleanup of from_src_file there t

migration: shut src return path unconditionally

We were do the shutting off only for postcopy. Now we do this as long as
the source return path is there.

Moving the cleanup of from_src_file there too.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

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migration: Create savevm.h for functions exported from savevm.c

This removes last trace of migration functions from sysemu/sysemu.h.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by:

migration: Create savevm.h for functions exported from savevm.c

This removes last trace of migration functions from sysemu/sysemu.h.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>

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exec: Create include for target_page_size()

That is the only function that we need from exec.c, and having to
include the whole sysemu.h for this.

Signed-off-by: Juan Quintela <quintela@redhat.com>

exec: Create include for target_page_size()

That is the only function that we need from exec.c, and having to
include the whole sysemu.h for this.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

---

/me leans to be less sloppy with copyright notices
thanks Dave

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