Re: [PATCH v2 13/40] vfio: Add support for Shared Virtual Addressing

Xu Zaibo
2018-09-04T02:12:37Z

On 2018/9/3 18:34, Jean-Philippe Brucker wrote:
> On 01/09/18 03:23, Xu Zaibo wrote:
>> As one application takes a whole function while using VFIO-PCI, why do
>> the application and the
>> function need to enable PASID capability? (Since just one I/O page table
>> is enough for them.)
> At the moment the series doesn't provide support for SVA without PASID
> (on the I/O page fault path, 08/40). In addition the BIND ioctl could be
> used by the owner application to bind other processes (slaves) and
> perform sub-assignment. But that feature is incomplete because we don't
> send stop_pasid notification to the owner when a slave dies.
>
So, Could I understand like this?

1. While the series are finished well, VFIO-PCI device can be held
by only one process
through binding IOCTL command without PASID (without PASID
being exposed user space).

2. While using VFIO-PCI device to support multiple processes with
SVA series, a primary
process with multiple secondary processes must be deployed just
like DPDK(https://www.dpdk.org/).
And, the PASID still has to be exposed to user land.

Thanks,
Zaibo

.