On 2018/9/3 18:34, Jean-Philippe Brucker wrote:

On 01/09/18 03:23, Xu Zaibo wrote:

quoted

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

.