Re: [Qemu-arm] [Qemu-devel] [PATCH v2 1/3] boards.h: Define new flag ignore_memory_transaction_failures

[Alistair Francis]

On Tue, Sep 5, 2017 at 9:03 AM, Richard Henderson
<address@hidden> wrote:
> On 09/05/2017 08:53 AM, Peter Maydell wrote:
>> Define a new MachineClass field ignore_memory_transaction_failures.
>> If this is flag is true then the CPU will ignore memory transaction
>> failures which should cause the CPU to take an exception due to an
>> access to an unassigned physical address; the transaction will
>> instead return zero (for a read) or be ignored (for a write).  This
>> should be set only by legacy board models which rely on the old
>> RAZ/WI behaviour for handling devices that QEMU does not yet model.
>> New board models should instead use "unimplemented-device" for all
>> memory ranges where the guest will attempt to probe for a device that
>> QEMU doesn't implement and a stub device is required.
>>
>> We need this for ARM boards, where we're about to implement support for
>> generating external aborts on memory transaction failures. Too many
>> of our legacy board models rely on the RAZ/WI behaviour and we
>> would break currently working guests when their "probe for device"
>> code provoked an external abort rather than a RAZ.
>>
>> Signed-off-by: Peter Maydell <address@hidden>
>> ---
>>  include/hw/boards.h | 11 +++++++++++
>>  include/qom/cpu.h   |  7 ++++++-
>>  qom/cpu.c           | 16 ++++++++++++++++
>>  3 files changed, 33 insertions(+), 1 deletion(-)
>
> Reviewed-by: Richard Henderson <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Thanks,
Alistair

>
>
> r~
>