Re: [Qemu-ppc] [PATCH v5 27/36] sysbus: add a sysbus_mmio_unmap() helper

[Cédric Le Goater]

On 11/29/18 5:36 PM, Cédric Le Goater wrote:
> On 11/29/18 5:09 AM, David Gibson wrote:
>> On Fri, Nov 16, 2018 at 11:57:20AM +0100, Cédric Le Goater wrote:
>>> This will be used to remove the MMIO regions of the POWER9 XIVE
>>> interrupt controller when the sPAPR machine is reseted.
>>>
>>> Signed-off-by: Cédric Le Goater <address@hidden>
>>
>> Reviewed-by: David Gibson <address@hidden>
>>
>> Since the code looks sane.
>>
>> Hoever, I think using memory_region_set_enabled() would be a better
>> idea for our purposes than actually adding/deleting the subregion.
> 
> Yes and we might not need this one anymore. 

As we are destroying the KVM device, we also need to remove the mmap 
in QEMU, else we will have a VMA with a page fault handler pointing
on a bogus KVM device.  which means destroying the memory region, so
we can not use  memory_region_set_enabled(). 

Anyhow mapping/unmapping works well.

Thanks,

C.