Re: [PATCH v6 6/8] virtio: add vfio api to rd/wr ioport space

On Tue, Feb 02, 2016 at 10:00:36AM +0530, Santosh Shukla wrote:

quoted

BTW, I didn't follow the noIOMMU discussion; how did it end? Do we still
need that? Is this patch a full story to enable virtio on ARM?

Ok, We agreed that explicit __noiommu suffix not required, atleast for
rte_xx_drv struct{}, as because sooner than later we'll have virtio
working for both flavours ie... iommu/noiommu. My only worry was
parsing for _noiommu and default vfio case, as because noiomu needed
user to preset "enable_noiommu_" param for vfio driver to do mode
switch. But we wont need that parsing as because if param is not set
then binding won't happen, which Thomas rightly pointed out, therefore
I choose to drop resource parsing for virtio-for-vfio case, now virtio
driver to check only drv->kdrv == RTE_KDRV_VFIO so to make sure
interface attached to vfio or not.

But perhaps when we have both flavours working for virtio, then we
should at least prompt a  INFO message on console that virtio pmd
driver attached to default vfio or noIOMMU.

So we don't need explicit _noIOMMU.

Thanks for the explanation.

Yes this patch is to enable non-x86 arch to use virtio pmd driver
(virtio 0.95 spec). After this patch merges-in, I am planning to
- replace sys/io.h entirely

Hmm, be more specific? Replace it with what?

- Add raw_read/raw_writel() api for arm/arm64 {Already proposed
similar implementation in v2} so that they could use virtio 1.0spec
mapped memory, for both UIO/VFIO mode.

PCI memory bar mapping works both with UIO/VFIO on ARM, without
any extra efforts, right? If so, it should just work with my
patch set and yours.

	--yliu