[Qemu-devel] [PATCH 0/2] pc: fix /etc/acpi/tables size in fw_cfg for -M pc-2.0

[Paolo Bonzini <pbonzini@redhat.com>]

Changing the ACPI table size causes migration to break, and the memory
hotplug work opened our eyes on how horribly we were breaking things in
2.0 already.

Unfortunately when reviewing the design I assumed incorrectly that all
tables would be placed in separate fw_cfg files.  This would have been
better, because you can always move stuff to a new SSDT (and thus a new
file), keeping the sizes under control.

Hard-code 64k as the maximum ACPI table size; for -M pc-i440fx-2.0
and -M pc-i440fx-1.7 compute the payload size of QEMU 2.0 and always
use that one.  This works always for QEMU 2.0, and also for 1.7
except for a few values of "-smp maxcpus".

The first patch is needed to shrink the ACPI tables and make them
smaller than they used to be in 2.0.

Please test and ack.  I'll do more testing tomorrow.

Paolo


Paolo Bonzini (2):
  acpi-dsdt: procedurally generate _PRT
  pc: hack for migration compatibility from QEMU 2.0

 hw/i386/acpi-build.c  | 61 +++++++++++++++++++++++++++++++---
 hw/i386/acpi-dsdt.dsl | 90 ++++++++++++++++++++++-----------------------------
 hw/i386/pc_piix.c     | 20 ++++++++++++
 hw/i386/pc_q35.c      |  5 +++
 include/hw/i386/pc.h  |  1 +
 5 files changed, 122 insertions(+), 55 deletions(-)

-- 
1.8.3.1