[Qemu-commits] [qemu/qemu] 17f30e: vl: Fix error location of positional arguments

[Peter Maydell]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: 17f30eae122a0a336dfe96cd525c96007414f7fb
      
https://github.com/qemu/qemu/commit/17f30eae122a0a336dfe96cd525c96007414f7fb
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M vl.c

  Log Message:
  -----------
  vl: Fix error location of positional arguments

We blame badness in positional arguments on the last option argument:

    $ qemu-system-x86_64 -vnc :1 bad.img
    qemu-system-x86_64: -vnc :1: Could not open 'foo': No such file or directory

I believe we've done this ever since we reported locations.  Fix it to

    qemu-system-x86_64: bad.img: Could not open 'bad.img': No such file or 
directory

Reported-by: Daniel P. Berrangé <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Daniel P. Berrangé <address@hidden>
Reviewed-by: Stefano Garzarella <address@hidden>


  Commit: 966c0d49326b2d18bff0b1f36f4d44802371a412
      
https://github.com/qemu/qemu/commit/966c0d49326b2d18bff0b1f36f4d44802371a412
  Author: Zhang Chen <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M qapi/migration.json

  Log Message:
  -----------
  qapi/migration.json: Fix ColoStatus member last_mode's version

Signed-off-by: Zhang Chen <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
[Commit message tweaked as per Eric's review]
Signed-off-by: Markus Armbruster <address@hidden>


  Commit: 5cc8f9eb7a11e2c8635c2e62d7651daf9e3bff42
      
https://github.com/qemu/qemu/commit/5cc8f9eb7a11e2c8635c2e62d7651daf9e3bff42
  Author: Zhang Chen <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M qapi/migration.json

  Log Message:
  -----------
  qapi/migration.json: Rename COLOStatus last_mode to last-mode

Signed-off-by: Zhang Chen <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
[Commit message rephrased]
Signed-off-by: Markus Armbruster <address@hidden>


  Commit: 2fa23277d58ce7ec527541b3baf52894ded530cc
      
https://github.com/qemu/qemu/commit/2fa23277d58ce7ec527541b3baf52894ded530cc
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M vl.c

  Log Message:
  -----------
  Revert "vl: Fix to create migration object before block backends again"

This reverts commit e60483f2f8498ae08ae79ca4c6fb03a3317f5e1e.

Recent commit cda4aa9a5a0 moved block backend creation before machine
property evaluation.  This broke block backends registering migration
blockers.  Commit e60483f2f84 fixed it by moving migration object
creation before block backend creation.  This broke migration with
Xen.  Turns out we need to configure the accelerator before we create
the migration object so that Xen's accelerator compat properties get
applied.  Revert the flawed commit.  This fixes the Xen regression,
but brings back the block backend regression.  The next commits will
fix it again.

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>


  Commit: 811f8652712a4ec2ff73c2c5dca35581a25112a4
      
https://github.com/qemu/qemu/commit/811f8652712a4ec2ff73c2c5dca35581a25112a4
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M include/sysemu/sysemu.h
    M migration/migration.c
    M migration/migration.h
    M migration/savevm.c
    M vl.c

  Log Message:
  -----------
  Revert "migration: move only_migratable to MigrationState"

This reverts commit 3df663e575f1876d7f3bc684f80e72fca0703d39.
This reverts commit b605c47b57b58e61a901a50a0762dccf43d94783.

Command line option --only-migratable is for disallowing any
configuration that can block migration.

Initially, --only-migratable set global variable @only_migratable.

Commit 3df663e575 "migration: move only_migratable to MigrationState"
replaced it by MigrationState member @only_migratable.  That was a
mistake.

First, it doesn't make sense on the design level.  MigrationState
captures the state of an individual migration, but --only-migratable
isn't a property of an individual migration, it's a restriction on
QEMU configuration.  With fault tolerance, we could have several
migrations at once.  --only-migratable would certainly protect all of
them.  Storing it in MigrationState feels inappropriate.

Second, it contributes to a dependency cycle that manifests itself as
a bug now.

Putting @only_migratable into MigrationState means its available only
after migration_object_init().

We can't set it before migration_object_init(), so we delay setting it
with a global property (this is fixup commit b605c47b57 "migration:
fix handling for --only-migratable").

We can't get it before migration_object_init(), so anything that uses
it can only run afterwards.

Since migrate_add_blocker() needs to obey --only-migratable, any code
adding migration blockers can run only afterwards.  This contributes
to the following dependency cycle:

* configure_blockdev() must run before machine_set_property()
  so machine properties can refer to block backends

* machine_set_property() before configure_accelerator()
  so machine properties like kvm-irqchip get applied

* configure_accelerator() before migration_object_init()
  so that Xen's accelerator compat properties get applied.

* migration_object_init() before configure_blockdev()
  so configure_blockdev() can add migration blockers

The cycle was closed when recent commit cda4aa9a5a0 "Create block
backends before setting machine properties" added the first
dependency, and satisfied it by violating the last one.  Broke block
backends that add migration blockers.

Moving @only_migratable into MigrationState was a mistake.  Revert it.

This doesn't quite break the "migration_object_init() before
configure_blockdev() dependency, since migrate_add_blocker() still has
another dependency on migration_object_init().  To be addressed the
next commit.

Note that the reverted commit made -only-migratable sugar for -global
migration.only-migratable=on below the hood.  Documentation has only
ever mentioned -only-migratable.  This commit removes the arcane &
undocumented alternative to -only-migratable again.  Nobody should be
using it.

Conflicts:
        include/migration/misc.h
        migration/migration.c
        migration/migration.h
        vl.c

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>


  Commit: daff7f0bbe9950d045bb5b74f202295f70ab3aaa
      
https://github.com/qemu/qemu/commit/daff7f0bbe9950d045bb5b74f202295f70ab3aaa
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M migration/migration.c

  Log Message:
  -----------
  migration: Support adding migration blockers earlier

migrate_add_blocker() asserts we have a current_migration object, in
migrate_get_current().  We do only after migration_object_init().

This contributes to the following dependency cycle:

* configure_blockdev() must run before machine_set_property()
  so machine properties can refer to block backends

* machine_set_property() before configure_accelerator()
  so machine properties like kvm-irqchip get applied

* configure_accelerator() before migration_object_init()
  so that Xen's accelerator compat properties get applied.

* migration_object_init() before configure_blockdev()
  so configure_blockdev() can add migration blockers

The cycle was closed when recent commit cda4aa9a5a0 "Create block
backends before setting machine properties" added the first
dependency, and satisfied it by violating the last one.  Broke block
backends that add migration blockers, as demonstrated by qemu-iotests
055.

To fix it, break the last dependency: make migrate_add_blocker()
usable before migration_object_init().

The previous commit already removed the use of migrate_get_current()
from migrate_add_blocker() itself.  Didn't quite do the trick, as
there's another one hiding in migration_is_idle().

The use there isn't actually necessary: when no migration object has
been created yet, migration is surely idle.  Make migration_is_idle()
return true then.

Fixes: cda4aa9a5a08777cf13e164c0543bd4888b8adce
Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>


  Commit: 0427b6257e2a901d60c58cad6f1b750a76fad4a8
      
https://github.com/qemu/qemu/commit/0427b6257e2a901d60c58cad6f1b750a76fad4a8
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M vl.c

  Log Message:
  -----------
  vl: Document dependencies hiding in global and compat props

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>


  Commit: 79b9d4bde7db3f760851217b329c68a883184c6b
      
https://github.com/qemu/qemu/commit/79b9d4bde7db3f760851217b329c68a883184c6b
  Author: Markus Armbruster <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M accel/accel.c

  Log Message:
  -----------
  accel: Unbreak accelerator fallback

When the user specifies a list of accelerators, we pick the first one
that initializes successfully.  Recent commit 1a3ec8c1564 broke that.
Reproducer:

    $ qemu-system-x86_64 --machine accel=xen:tcg
    xencall: error: Could not obtain handle on privileged command interface: No 
such file or directory
    xen be core: xen be core: can't open xen interface
    can't open xen interface
    qemu-system-x86_64: failed to initialize Xen: Operation not permitted
    qemu-system-x86_64: /home/armbru/work/qemu/qom/object.c:436: 
object_set_accelerator_compat_props: Assertion `!object_compat_props[0]' failed.

Root cause: we register accelerator compat properties even when the
accelerator fails.  The failed assertion is
object_set_accelerator_compat_props() telling us off.  Fix by calling
it only for the accelerator that succeeded.

Fixes: 1a3ec8c1564f51628cce10d435a2e22559ea29fd
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Message-Id: <address@hidden>


  Commit: 37301a8d0fe2b2a837747548c1ecf7d73b6fe8ab
      
https://github.com/qemu/qemu/commit/37301a8d0fe2b2a837747548c1ecf7d73b6fe8ab
  Author: Peter Maydell <address@hidden>
  Date:   2019-04-02 (Tue, 02 Apr 2019)

  Changed paths:
    M accel/accel.c
    M include/sysemu/sysemu.h
    M migration/migration.c
    M migration/migration.h
    M migration/savevm.c
    M qapi/migration.json
    M vl.c

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/armbru/tags/pull-misc-2019-04-02' into 
staging

Miscellaneous patches for 2019-04-02

# gpg: Signature made Tue 02 Apr 2019 12:54:27 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <address@hidden>" [full]
# gpg:                 aka "Markus Armbruster <address@hidden>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-misc-2019-04-02:
  accel: Unbreak accelerator fallback
  vl: Document dependencies hiding in global and compat props
  migration: Support adding migration blockers earlier
  Revert "migration: move only_migratable to MigrationState"
  Revert "vl: Fix to create migration object before block backends again"
  qapi/migration.json: Rename COLOStatus last_mode to last-mode
  qapi/migration.json: Fix ColoStatus member last_mode's version
  vl: Fix error location of positional arguments

Signed-off-by: Peter Maydell <address@hidden>


Compare: https://github.com/qemu/qemu/compare/436960c95946...37301a8d0fe2