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>
Currently various acpi hotplug modules like cpu hotplug, memory hotplug, pci
hotplug, nvdimm hotplug are all pulled in when CONFIG_ACPI_X86 is turned on.
This brings in support for whole lot of subsystems that some targets like
mips does not need. They are added just to satisfy symbol dependencies. This
is ugly and should be avoided. Targets should be able to pull in just what they
need and no more. For example, mips only needs support for PIIX4 and does not
need acpi pci hotplug support or cpu hotplug support or memory hotplug support
etc. This change is an effort to clean this up.
In this change, new config variables are added for various acpi hotplug
subsystems. Targets like mips can only enable PIIX4 support and not the rest
of all the other modules which were being previously pulled in as a part of
CONFIG_ACPI_X86. Function stubs make sure that symbols which piix4 needs but
are not required by mips (for example, symbols specific to pci hotplug etc)
are available to satisfy the dependencies.
Currently, this change only addresses issues with mips malta targets. In future
we might be able to clean up other targets which are similarly pulling in lot
of unnecessary hotplug modules by enabling ACPI_X86.
This change should also address issues such as the following:
https://gitlab.com/qemu-project/qemu/-/issues/221https://gitlab.com/qemu-project/qemu/-/issues/193
Signed-off-by: Ani Sinha <ani@anisinha.ca>
Message-Id: <20210812071409.492299-1-ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
