xemu/hw/i386
Gerd Hoffmann 8156d48086 pc: allow raising low memory via max-ram-below-4g option
This patch extends the functionality of the max-ram-below-4g option
to also allow increasing lowmem.  Use case: Give as much memory as
possible to legacy non-PAE guests.

While being at it also rework the lowmem calculation logic and add a
longish comment describing how it works and what the compatibility
constrains are.

Note:  This is a incompatible change.  When setting max-ram-below-4g to
a value larger than 3.5G (or 3G with gigabyte alignment) it has no
effect on older qemu versions: qemu silently ignores it.  With the patch
applied it actually has an effect and changes the ram layout.  Highly
unlikely to hit in practive though as there is no reason start old qemu
versions that way.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1464857305-26675-1-git-send-email-kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-06 18:57:06 +02:00
..
kvm qemu-common: push cpu.h inclusion out of qemu-common.h 2016-05-19 16:42:29 +02:00
xen include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
Makefile.objs pc: acpi: remove unused ASL templates and related blobs/utils 2016-01-09 23:20:19 +02:00
acpi-build.c ACPI: move acpi_build_srat_memory to common place 2016-05-12 13:22:28 +01:00
acpi-build.h Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00
intel_iommu.c intel_iommu: large page support 2016-02-06 20:44:10 +02:00
intel_iommu_internal.h intel_iommu: large page support 2016-02-06 20:44:10 +02:00
kvmvapic.c i386: kvmvapic: initialise imm32 variable 2016-05-23 16:53:43 +02:00
multiboot.c hw: explicitly include qemu-common.h and cpu.h 2016-03-22 22:20:17 +01:00
multiboot.h refer to FWCfgState explicitly 2013-06-02 18:14:02 +03:00
pc.c pc: allow raising low memory via max-ram-below-4g option 2016-06-06 18:57:06 +02:00
pc_piix.c pc: allow raising low memory via max-ram-below-4g option 2016-06-06 18:57:06 +02:00
pc_q35.c Sort the fw_cfg file list 2016-04-07 19:57:33 +03:00
pc_sysfw.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
pci-assign-load-rom.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00