error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() a

error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() at
the beginning of the functions.

As stated in the commit 05e385d2a9: "include/qapi/error.h advises to put
ERRP_GUARD() right at the beginning of the function, because only then
can it guard the whole function.", so clean up the few spots
disregarding the advice.

Inspired-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240312060337.3240965-1-zhao1.liu@linux.intel.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

show more ...

error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() a

error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() at
the beginning of the functions.

As stated in the commit 05e385d2a9: "include/qapi/error.h advises to put
ERRP_GUARD() right at the beginning of the function, because only then
can it guard the whole function.", so clean up the few spots
disregarding the advice.

Inspired-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240312060337.3240965-1-zhao1.liu@linux.intel.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

show more ...

error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() a

error: Move ERRP_GUARD() to the beginning of the function

Since the commit 05e385d2a9 ("error: Move ERRP_GUARD() to the beginning
of the function"), there are new codes that don't put ERRP_GUARD() at
the beginning of the functions.

As stated in the commit 05e385d2a9: "include/qapi/error.h advises to put
ERRP_GUARD() right at the beginning of the function, because only then
can it guard the whole function.", so clean up the few spots
disregarding the advice.

Inspired-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240312060337.3240965-1-zhao1.liu@linux.intel.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

show more ...

migration: remove error from notifier data

Remove the error object from opaque data passed to notifiers.
Use the new error parameter passed to the notifier instead.

Signed-off-by: Steve Sistare <st

migration: remove error from notifier data

Remove the error object from opaque data passed to notifiers.
Use the new error parameter passed to the notifier instead.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/1708622920-68779-3-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

notify: pass error to notifier with return

Pass an error object as the third parameter to "notifier with return"
notifiers, so clients no longer need to bundle an error object in the
opaque data. T

notify: pass error to notifier with return

Pass an error object as the third parameter to "notifier with return"
notifiers, so clients no longer need to bundle an error object in the
opaque data. The new parameter is used in a later patch.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/1708622920-68779-2-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

userfaultfd: use 1ULL to build ioctl masks

There is no need to use the Linux-internal __u64 type, 1ULL is
guaranteed to be wide enough.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-b

userfaultfd: use 1ULL to build ioctl masks

There is no need to use the Linux-internal __u64 type, 1ULL is
guaranteed to be wide enough.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20240117160313.175609-1-pbonzini@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

userfaultfd: use 1ULL to build ioctl masks

There is no need to use the Linux-internal __u64 type, 1ULL is
guaranteed to be wide enough.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-b

userfaultfd: use 1ULL to build ioctl masks

There is no need to use the Linux-internal __u64 type, 1ULL is
guaranteed to be wide enough.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20240117160313.175609-1-pbonzini@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket:

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket: Connection reset by peer
Memory content inconsistency at 5b43000 first_byte = bd last_byte = bc current = 4f hit_edge = 1
**
ERROR:../tests/qtest/migration-test.c:300:check_guests_ram: assertion failed: (bad == 0)
(test program exited with status code -6)

Fabiano debugged into it and found that the preempt thread can quit even
without receiving all the pages, which can cause guest not receiving all
the pages and corrupt the guest memory.

To make sure preempt thread finished receiving all the pages, we can rely
on the page_requested_count being zero because preempt channel will only
receive requested page faults. Note, not all the faulted pages are required
to be sent via the preempt channel/thread; imagine the case when a
requested page is just queued into the background main channel for
migration, the src qemu will just still send it via the background channel.

Here instead of spinning over reading the count, we add a condvar so the
main thread can wait on it if that unusual case happened, without burning
the cpu for no good reason, even if the duration is short; so even if we
spin in this rare case is probably fine. It's just better to not do so.

The condvar is only used when that special case is triggered. Some memory
ordering trick is needed to guarantee it from happening (against the
preempt thread status field), so the main thread will always get a kick
when that triggers correctly.

Closes: https://gitlab.com/qemu-project/qemu/-/issues/1886
Debugged-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-2-farosas@suse.de>

show more ...

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket:

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket: Connection reset by peer
Memory content inconsistency at 5b43000 first_byte = bd last_byte = bc current = 4f hit_edge = 1
**
ERROR:../tests/qtest/migration-test.c:300:check_guests_ram: assertion failed: (bad == 0)
(test program exited with status code -6)

Fabiano debugged into it and found that the preempt thread can quit even
without receiving all the pages, which can cause guest not receiving all
the pages and corrupt the guest memory.

To make sure preempt thread finished receiving all the pages, we can rely
on the page_requested_count being zero because preempt channel will only
receive requested page faults. Note, not all the faulted pages are required
to be sent via the preempt channel/thread; imagine the case when a
requested page is just queued into the background main channel for
migration, the src qemu will just still send it via the background channel.

Here instead of spinning over reading the count, we add a condvar so the
main thread can wait on it if that unusual case happened, without burning
the cpu for no good reason, even if the duration is short; so even if we
spin in this rare case is probably fine. It's just better to not do so.

The condvar is only used when that special case is triggered. Some memory
ordering trick is needed to guarantee it from happening (against the
preempt thread status field), so the main thread will always get a kick
when that triggers correctly.

Closes: https://gitlab.com/qemu-project/qemu/-/issues/1886
Debugged-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-2-farosas@suse.de>

show more ...

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket:

migration: Fix race that dest preempt thread close too early

We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:

qemu-system-x86_64: Unable to read from socket: Connection reset by peer
Memory content inconsistency at 5b43000 first_byte = bd last_byte = bc current = 4f hit_edge = 1
**
ERROR:../tests/qtest/migration-test.c:300:check_guests_ram: assertion failed: (bad == 0)
(test program exited with status code -6)

Fabiano debugged into it and found that the preempt thread can quit even
without receiving all the pages, which can cause guest not receiving all
the pages and corrupt the guest memory.

To make sure preempt thread finished receiving all the pages, we can rely
on the page_requested_count being zero because preempt channel will only
receive requested page faults. Note, not all the faulted pages are required
to be sent via the preempt channel/thread; imagine the case when a
requested page is just queued into the background main channel for
migration, the src qemu will just still send it via the background channel.

Here instead of spinning over reading the count, we add a condvar so the
main thread can wait on it if that unusual case happened, without burning
the cpu for no good reason, even if the duration is short; so even if we
spin in this rare case is probably fine. It's just better to not do so.

The condvar is only used when that special case is triggered. Some memory
ordering trick is needed to guarantee it from happening (against the
preempt thread status field), so the main thread will always get a kick
when that triggers correctly.

Closes: https://gitlab.com/qemu-project/qemu/-/issues/1886
Debugged-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-2-farosas@suse.de>

show more ...

migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()

virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incom

migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()

virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incoming migration.

So let's expose that function as migrate_ram_is_ignored() in
migration/misc.h

Message-ID: <20230706075612.67404-4-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

show more ...

migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()

virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incom

migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()

virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incoming migration.

So let's expose that function as migrate_ram_is_ignored() in
migration/misc.h

Message-ID: <20230706075612.67404-4-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

show more ...

migration: Drop unused parameter for migration_tls_client_create()

It is not needed since we moved the accessor for tls properties to
options.c.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsements

migration: Drop unused parameter for migration_tls_client_create()

It is not needed since we moved the accessor for tls properties to
options.c.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

show more ...

migration: Allow postcopy_ram_supported_by_host() to report err

Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.

E.g.:

{ "execute": "migrate-set

migration: Allow postcopy_ram_supported_by_host() to report err

Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.

E.g.:

{ "execute": "migrate-set-capabilities" ,
"arguments": { "capabilities":
[ { "capability": "postcopy-ram", "state": true } ] } }

{ "error":
{ "class": "GenericError",
"desc": "Postcopy is not supported: Host backend files need to be TMPFS
or HUGETLBFS only" } }

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

show more ...

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

--

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

---

Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.

What do you think?

show more ...

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

Do that early right at enabling of postcopy.

Note that this is still only a best effort because ramblocks can be
dynamically created. We can add check in hostmem creations and fail if
postcopy enabled, but maybe that's too aggressive.

Still, we have chance to fail the most obvious where we know there's an
existing unsupported ramblock.

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

show more ...

postcopy-ram: do not use qatomic_mb_read

It does not even pair with a qatomic_mb_set(), so it is clearer to use
load-acquire in this case; they are synonyms.

Signed-off-by: Paolo Bonzini <pbonzini@

postcopy-ram: do not use qatomic_mb_read

It does not even pair with a qatomic_mb_set(), so it is clearer to use
load-acquire in this case; they are synonyms.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

migration: Drop unused parameter for migration_tls_client_create()

It is not needed since we moved the accessor for tls properties to
options.c.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsements

migration: Drop unused parameter for migration_tls_client_create()

It is not needed since we moved the accessor for tls properties to
options.c.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

show more ...

migration: Allow postcopy_ram_supported_by_host() to report err

Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.

E.g.:

{ "execute": "migrate-set

migration: Allow postcopy_ram_supported_by_host() to report err

Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.

E.g.:

{ "execute": "migrate-set-capabilities" ,
"arguments": { "capabilities":
[ { "capability": "postcopy-ram", "state": true } ] } }

{ "error":
{ "class": "GenericError",
"desc": "Postcopy is not supported: Host backend files need to be TMPFS
or HUGETLBFS only" } }

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

show more ...

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

--

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

---

Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.

What do you think?

show more ...

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

Do that early right at enabling of postcopy.

Note that this is still only a best effort because ramblocks can be
dynamically created. We can add check in hostmem creations and fail if
postcopy enabled, but maybe that's too aggressive.

Still, we have chance to fail the most obvious where we know there's an
existing unsupported ramblock.

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

show more ...

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

--

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

---

Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.

What do you think?

show more ...

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

migration/postcopy: Detect file system on dest host

Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).

Do that early right at enabling of postcopy.

Note that this is still only a best effort because ramblocks can be
dynamically created. We can add check in hostmem creations and fail if
postcopy enabled, but maybe that's too aggressive.

Still, we have chance to fail the most obvious where we know there's an
existing unsupported ramblock.

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

show more ...

postcopy-ram: do not use qatomic_mb_read

It does not even pair with a qatomic_mb_set(), so it is clearer to use
load-acquire in this case; they are synonyms.

Signed-off-by: Paolo Bonzini <pbonzini@

postcopy-ram: do not use qatomic_mb_read

It does not even pair with a qatomic_mb_set(), so it is clearer to use
load-acquire in this case; they are synonyms.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

--

migration: Create options.c

We move there all capabilities helpers from migration.c.

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

---

Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.

What do you think?

show more ...