Re: [Qemu-devel] [PATCHv2 0/4] Start allowing ISA to be configured out

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 02, 2015 at 03:53:43PM +1000, David Gibson wrote:
> At the moment isa-bus.c is compiled unconditionally for all targets.
> However, some targets have never used legacy ISA devices.  Many more
> targets have at least some machine types without ISA.
> 
> These patches allow ISA bus to be disabled in the configuration, thus
> allowing cut down configurations for targets and machine types that
> don't have ISA.
> 
> Actually turning off ISA will require more than this for most targets
> - there are a number of non-obvious dependencies on the ISA code.
> b19c1c0 "isa: remove isa_mem_base variable" already got rid of an
> important one (VGA depended on ISA).  Patches 2/4 and 4/4 in this
> series remove some more.  There are a number more though, for example
> CONFIG_IDE_CORE depends on ISA and the HMP "info irq" command depends
> on I8259 code.
> 
> This patch should allow easier experimentation so we can chip away at
> those dependencies on legacy code in the future.
> 
> Changes in v2:
>  * Removed changes to HMP, since it would cause a regression for PReP
>  * Added a cleanup of the dead CONFIG_ISA_MMIO variable
>  * Clearer explanation of the situation in commit messages

Overall I don't have a problem with this.
I think this needs to be deferred until after 2.4 though,
pls remember to re-post then.

> David Gibson (4):
>   Cleanup leftover CONFIG_ISA_MMIO
>   Split serial-isa into its own config option
>   Allow ISA bus to be configured out
>   Split ISA and sysbus versions of m48t59 device
> 
>  default-configs/alpha-softmmu.mak     |   1 +
>  default-configs/arm-softmmu.mak       |   2 +-
>  default-configs/i386-softmmu.mak      |   1 +
>  default-configs/mips-softmmu.mak      |   1 +
>  default-configs/mips64-softmmu.mak    |   1 +
>  default-configs/mips64el-softmmu.mak  |   1 +
>  default-configs/mipsel-softmmu.mak    |   1 +
>  default-configs/moxie-softmmu.mak     |   1 +
>  default-configs/pci.mak               |   1 +
>  default-configs/ppc-softmmu.mak       |   2 +-
>  default-configs/ppc64-softmmu.mak     |   2 +-
>  default-configs/ppcemb-softmmu.mak    |   1 +
>  default-configs/sh4-softmmu.mak       |   1 +
>  default-configs/sh4eb-softmmu.mak     |   1 +
>  default-configs/sparc-softmmu.mak     |   1 +
>  default-configs/sparc64-softmmu.mak   |   2 +-
>  default-configs/unicore32-softmmu.mak |   1 +
>  default-configs/x86_64-softmmu.mak    |   1 +
>  hw/char/Makefile.objs                 |   3 +-
>  hw/isa/Makefile.objs                  |   2 +-
>  hw/timer/Makefile.objs                |   3 +
>  hw/timer/m48t59-internal.h            |  82 ++++++++++++
>  hw/timer/m48t59-isa.c                 | 180 +++++++++++++++++++++++++++
>  hw/timer/m48t59.c                     | 228 +++-------------------------------
>  24 files changed, 304 insertions(+), 216 deletions(-)
>  create mode 100644 hw/timer/m48t59-internal.h
>  create mode 100644 hw/timer/m48t59-isa.c
> 
> -- 
> 2.4.3