[Qemu-commits] [qemu/qemu] a83c28: acpi: fix acpi_index migration

[Peter Maydell]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: a83c2844903c45aa7d32cdd17305f23ce2c56ab9
      
https://github.com/qemu/qemu/commit/a83c2844903c45aa7d32cdd17305f23ce2c56ab9
  Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Date:   2022-04-06 (Wed, 06 Apr 2022)

  Changed paths:
    M hw/acpi/acpi-pci-hotplug-stub.c
    M hw/acpi/pcihp.c
    M hw/acpi/piix4.c
    M hw/core/machine.c
    M include/hw/acpi/pcihp.h

  Log Message:
  -----------
  acpi: fix acpi_index migration

vmstate_acpi_pcihp_use_acpi_index() was expecting AcpiPciHpState
as state but it actually received PIIX4PMState, because
VMSTATE_PCI_HOTPLUG is a macro and not another struct.
So it ended up accessing random pointer, which resulted
in 'false' return value and acpi_index field wasn't ever
sent.

However in 7.0 that pointer de-references to value > 0, and
destination QEMU starts to expect the field which isn't
sent in migratioon stream from older QEMU (6.2 and older).
As result migration fails with:
  qemu-system-x86_64: Missing section footer for 0000:00:01.3/piix4_pm
  qemu-system-x86_64: load of migration failed: Invalid argument

In addition with QEMU-6.2, destination due to not expected
state, also never expects the acpi_index field in migration
stream.

Q35 is not affected as it always sends/expects the field as
long as acpi based PCI hotplug is enabled.

Fix issue by introducing compat knob to never send/expect
acpi_index in migration stream for 6.2 and older PC machine
types and always send it for 7.0 and newer PC machine types.

Diagnosed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Fixes: b32bd76 ("pci: introduce acpi-index property for PCI device")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/932
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>


  Commit: 95a3fcc7487e5bef262e1f937ed8636986764c4e
      
https://github.com/qemu/qemu/commit/95a3fcc7487e5bef262e1f937ed8636986764c4e
  Author: Peter Maydell <peter.maydell@linaro.org>
  Date:   2022-04-06 (Wed, 06 Apr 2022)

  Changed paths:
    M VERSION

  Log Message:
  -----------
  Update version for v7.0.0-rc3 release

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


Compare: https://github.com/qemu/qemu/compare/f53faa70bb63...95a3fcc7487e