Re: [Qemu-devel] [PATCH 0/2] Don't abort on writes to ROMs

[Paolo Bonzini]

On 13/12/2017 18:52, Peter Maydell wrote:
> Currently we set up the io_mem_rom special memory region using the
> unassigned_mem_ops structure; this is then used when a guest tries to
> write to ROM.  This is incorrect, because the behaviour of unassigned
> memory may be different from that of ROM for writes.  In particular,
> on some architectures writing to unassigned memory generates a guest
> exception, whereas writing to ROM is generally ignored.
> 
> This patchset creates a separate readonly_mem_ops for handling the
> writes to readonly memory, which just ignores them.
> 
> Patch 2 removes a workaround in the MIPS boston board which
> is no longer needed once the core memory system is fixed.
> 
> Disclaimer: I haven't tested the mips change beyond 'make check'
> (I tested the exec patch with a temporary hack to the Arm
> virt board), but I believe it to be correct...
> 
> thanks
> -- PMM
> 
> 
> Peter Maydell (2):
>   exec: Don't reuse unassigned_mem_ops for io_mem_rom
>   hw/mips/boston: Remove workaround for writes to ROM aborting
> 
>  exec.c           | 34 +++++++++++++++++++++++++++++++++-
>  hw/mips/boston.c | 14 ++------------
>  2 files changed, 35 insertions(+), 13 deletions(-)
> 

Queued for 2.12, thanks.

Paolo