Re: [PATCH v3 07/23] OvmfPkg/Virtio: take RingBaseShift in SetQueueAddress()

[Brijesh Singh <brijesh.singh@amd.com>]

On 08/23/2017 03:43 PM, Laszlo Ersek wrote:
> On 08/23/17 22:41, Laszlo Ersek wrote:
>> On 08/23/17 14:22, Brijesh Singh wrote:
>>> For the case when an IOMMU is used for translating system physical
>>> addresses to DMA bus master addresses, the transport-independent
>>> virtio device drivers will be required to map their VRING areas to
>>> bus addresses with VIRTIO_DEVICE_PROTOCOL.MapSharedBuffer() calls.
>>>
>>> VirtioRingMap() maps the ring buffer system physical to a bus address.
>>> When an IOMMU is used for translating the address then bus address can
>>> start at a different offset from the system physical address.
>>
>> (1) The paragraph that you now have as first paragraph above was my
>> suggestion, so thank you for picking it up. However, the second
>> paragraph should have been deleted; I suggested the now-first paragraph
>> as a replacement for the now-second one.
>>
>> I wrote, "to keep our references within the virtio device protocol".
>> VirtioRingMap() is a VirtioLib function, which is a utility layer on top
>> of the virtio device protocol. So, as I said, VirtioLib patches may
>> refer to both VirtioLib and the protocol, but protocol patches should
>> preferably only refer to the protocol, and not VirtioLib.
>>
>>    VirtioLib --+
>>     |  ^       |
>>     |  |       |
>>     |  +-------+
>>     |
>>     v
>>    VirtioDeviceProtocol --+
>>                  ^        |
>>                  |        |
>>                  +--------+
>>
>> This is also consistent with the reordering of the patches that I asked
>> for (and that you implemented well in v3, thank you for it).
>>
>> So, apologies if I wasn't clear enough of this -- it's not a big deal at
>> all, I can remove the second paragraph when I push this.
>>
>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>>

Thanks Laszlo, Sorry I did not realize that second paragraph should have been
deleted. Thanks for fixing.

-Brijesh