arch-run: Add a "continuous" migration option for tests

The cooperative migration protocol is very good to control precise
pre and post conditions for a migration event. However in some cases
its in

arch-run: Add a "continuous" migration option for tests

The cooperative migration protocol is very good to control precise
pre and post conditions for a migration event. However in some cases
its intrusiveness to the test program, can mask problems and make
analysis more difficult.

For example to stress test migration vs concurrent complicated
memory access, including TLB refill, ram dirtying, etc., then the
tight spin at getchar() and resumption of the workload after
migration is unhelpful.

This adds a continuous migration mode that directs the harness to
perform migrations continually. This is added to the migration
selftests, which also sees cooperative migration iterations reduced
to avoid increasing test time too much.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20240405083539.374995-6-npiggin@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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migration: Add a migrate_skip command

Tests that are run with MIGRATION=yes but skip due to some requirement
not being met will show as a failure due to the harness requirement to
see one successful

migration: Add a migrate_skip command

Tests that are run with MIGRATION=yes but skip due to some requirement
not being met will show as a failure due to the harness requirement to
see one successful migration. The workaround for this is to migrate in
test's skip path. Add a new command that just tells the harness to not
expect a migration.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20240405083539.374995-4-npiggin@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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migration: Add quiet migration support

Console output required to support migration becomes quite noisy
when doing lots of migrations. Provide a migrate_quiet() call that
suppresses console output a

migration: Add quiet migration support

Console output required to support migration becomes quite noisy
when doing lots of migrations. Provide a migrate_quiet() call that
suppresses console output and doesn't log a message.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20240221032757.454524-7-npiggin@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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migration: Support multiple migrations

Support multiple migrations by flipping dest file/socket variables to
source after the migration is complete, ready to start again. A new
destination is create

migration: Support multiple migrations

Support multiple migrations by flipping dest file/socket variables to
source after the migration is complete, ready to start again. A new
destination is created if the test outputs the migrate line again.
Test cases may now switch to calling migrate() one or more times.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20240221032757.454524-5-npiggin@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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lib: add function to request migration

Migration tests can ask migrate_cmd to migrate them to a new QEMU
process. Requesting migration and waiting for completion is hence a
common pattern which is r

lib: add function to request migration

Migration tests can ask migrate_cmd to migrate them to a new QEMU
process. Requesting migration and waiting for completion is hence a
common pattern which is repeated all over the code base. Add a function
which does all of that to avoid repeating the same pattern.

Since migrate_cmd currently can only migrate exactly once, this function
is called migrate_once() and is a no-op when it has been called before.
This can simplify the control flow, especially when tests are skipped.

Suggested-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20221212111731.292942-2-nrb@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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