Re: [Qemu-devel] [PATCH] virito: unbreak virtio device behinds IOMMU with region cache

[Jason Wang <jasowang@redhat.com>]

On 2017年03月03日 20:56, Paolo Bonzini wrote:
>
> On 03/03/2017 10:06, Jason Wang wrote:
>> Commit c611c76417f5 ("virtio: add MemoryListener to cache ring
>> translations") registers a memory listener to dma_as. This may not
>> work when IOMMU is enabled: dma_as(bus_master_as) were correctly
>> initialized in pcibus_machine_done() after virtio_realize() where we
>> try to register listener and initialize address space cache.
>>
>> Fixing this by:
>>
>> - delay the listener register to status set
>> - reset dma_as before trying to initialize address spaces to make sure
>>    it works even IOMMU were created after virtio device
>>
>> Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring translations")
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> For virtio 0.9 it is valid to use the virtio device while the status is 0.
>
> You can add a function virtio_set_dma_as to generic virtio that does a
> MemoryListener unregister+register, then PCI can call it when the
> AddressSpace is ready.
>
> Paolo
>
>

Ok, will post a new version.

Thanks