The guest cannot boot up with parameter "-no-acpi"

[chao zhou]

Environment:
------------
Host OS (ia32/ia32e/IA64):ia32e
Guest OS (ia32/ia32e/IA64):ia32e
Guest OS Type (Linux/Windows):Linux
kvm.git Commit:81e87e26796782e014fd1f2bb9cd8fb6ce4021a8
qemu.git Commit:a126050a103c924b03388a9a64ce9af8c96b0969
Host Kernel Version:3.12.0-rc5
Hardware:Romley_EP ,Ivytowm_EP

Bug detailed description:
--------------------------
when create guest with parameter "-no-acpi", the guest cannot boot up.

note: this should be a qemu bug
kvm + qemu = result
81e87e26 + a126050a = bad
81e87e26 + b8616055 = good

Reproduce steps:
----------------
1. create guest
qemu-system-x86_64 -enable-kvm -m 1024 -smp 2 -net none -no-acpi rhel6u4.qcow

Current result:
----------------
guest cannot boot up

Expected result:
----------------
guest boot up fine.

Basic root-causing log:
----------------------
[root@vt-snb9 qemu]#qemu-system-x86_64 -enable-kvm -m 1024 -smp 2 -net none /root/rhel6u4.qcow -no-acpi
VNC server running on `::1:5900'
qemu-system-x86_64: /root/qemu/hw/i386/acpi-build.c:135: acpi_get_pm_info: Assertion `obj' failed.
Aborted (core dumped)

[chao zhou (chao-zhou)]

the first bad commit is:
commit 72c194f7e75cb64b2558111cb111adb49fbf4097
Author: Michael S. Tsirkin <email address hidden>
Date: Wed Jul 24 18:56:14 2013 +0300

    i386: ACPI table generation code from seabios

    This adds C code for generating ACPI tables at runtime,
    imported from seabios git tree
        commit 51684b7ced75fb76776e8ee84833fcfb6ecf12dd

    Although ACPI tables come from a system BIOS on real hw,
    it makes sense that the ACPI tables are coupled with the
    virtual machine, since they have to abstract the x86 machine to
    the OS's.

    This is widely desired as a way to avoid the churn
    and proliferation of QEMU-specific interfaces
    associated with ACPI tables in bios code.

    Notes:
    As BIOS can reprogram devices prior to loading
    ACPI tables, we pre-format ACPI tables but defer loading
    hardware configuration there until tables are loaded.

    The code structure was intentionally kept as close
    to the seabios original as possible, to simplify
    comparison and making sure we didn't lose anything
    in translation.

    Minor code duplication results, to help ensure there are no functional
    regressions, I think it's better to merge it like this and do more code
    changes in follow-up patches.

    Cross-version compatibility concerns have been addressed:
        ACPI tables are exposed to guest as FW_CFG entries.
        When running with -M 1.5 and older, this patch disables ACPI
        table generation, and doesn't expose ACPI
        tables to guest.

        As table content is likely to change over time,
        the following measures are taken to simplify
        cross-version migration:
        - All tables besides the RSDP are packed in a single FW CFG entry.
          This entry size is currently 23K. We round it up to 64K
          to avoid too much churn there.
        - Tables are placed in special ROM blob (not mapped into guest memory)
          which is automatically migrated together with the guest, same
          as BIOS code.
        - Offsets where hardware configuration is loaded in ACPI tables
          are also migrated, this is in case future ACPI changes make us
          rearrange the tables in memory.

    This patch reuses some code from SeaBIOS, which was originally under
    LGPLv2 and then relicensed to GPLv3 or LGPLv3, in QEMU under GPLv2+. This
    relicensing has been acked by all contributors that had contributed to the
    code since the v2->v3 relicense. ACKs approving the v2+ relicensing are
    listed below. The list might include ACKs from people not holding
    copyright on any parts of the reused code, but it's better to err on the
    side of caution and include them.

[chao zhou (chao-zhou)]

kvm.git + qemu.git: ede58222_5c5432e7
test on Romley_EP, Ivytown_EP, create guest with parameter "-no-acpi", the guest boot up fine.