RE: [Patch v4 0/3] Introduce a driver to support host accelerated access to Microsoft Azure Blob

[Long Li]

> Subject: Re: [Patch v4 0/3] Introduce a driver to support host accelerated
> access to Microsoft Azure Blob
> 
> On Mon, Jul 19, 2021 at 09:37:56PM -0700, Bart Van Assche wrote:
> > such that this object storage driver can be implemented as a
> > user-space library instead of as a kernel driver? As you may know vfio
> > users can either use eventfds for completion notifications or polling.
> > An interface like io_uring can be built easily on top of vfio.
> 
> Yes.  Similar to say the NVMe K/V command set this does not look like a
> candidate for a kernel driver.

The driver is modeled to support multiple processes/users over a VMBUS
channel. I don't see a way that this can be implemented through VFIO? 

Even if it can be done, this exposes a security risk as the same VMBUS
channel is shared by multiple processes in user-mode.