Re: [Qemu-devel] [PATCH 0/2] Drop support for qdev taddr properties

[Paolo Bonzini <pbonzini@redhat.com>]

Il 02/04/2013 18:10, Peter Maydell ha scritto:
> There is currently only one user of the qdev taddr (target addr,
> now hwaddr) property code, and that user is wrong anyway, since the
> property it's trying to set isn't actually a taddr property.
> Fix the erroneous use in sm501 and drop all the taddr property code.
> 
> The justification for dropping the support is that a device should
> generally not be exposing properties whose width (conceptually)
> depends on the target CPU type. (This is the same rationale for
> not supporting hwaddr fields in migration state.) Instead the
> device should expose either a 32 bit or 64 bit property, depending
> on what the actual hardware does.
> 
> Aside: I may try to get rid of the DMAADDR property too at some
> point, because what the sysbus-ohci device should actually be doing
> is taking a MemoryRegion* [or maybe a DMAContext*]

Avi had patches to unify DMAContext and MemoryRegion.  I should revive
them perhaps.

> representing what
> it should be DMAing into, rather than the current "DMA into the
> system address space at addr + some constant offset" hack. One
> thing at a time, though.

That's a general problem with sysbus.  I guess if you need another
address space you should define your own bus, like PCI does.

Paolo

> Peter Maydell (2):
>   hw/sm501: Use correct setter for sysbus-ohci dma-address property
>   qdev: Drop taddr properties
> 
>  hw/Makefile.objs        |  1 -
>  hw/fdc.c                |  1 -
>  hw/milkymist-hw.h       |  1 -
>  hw/milkymist-minimac2.c |  1 -
>  hw/qdev-addr.c          | 78 -------------------------------------------------
>  hw/qdev-addr.h          | 10 -------
>  hw/sm501.c              |  3 +-
>  hw/sparc/sun4m.c        |  1 -
>  hw/tcx.c                |  1 -
>  hw/xilinx_axidma.c      |  1 -
>  10 files changed, 1 insertion(+), 97 deletions(-)
>  delete mode 100644 hw/qdev-addr.c
>  delete mode 100644 hw/qdev-addr.h
>