RE: [Patch v5 0/3] Introduce a driver to support host accelerated access to Microsoft Azure Blob for Azure VM

From: Long Li
Date: Mon Oct 11 2021 - 13:46:56 EST


> Subject: Re: [Patch v5 0/3] Introduce a driver to support host accelerated access
> to Microsoft Azure Blob for Azure VM
>
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> writes:
>
> ...
> >
> > Not to mention the whole crazy idea of "let's implement our REST api
> > that used to go over a network connection over an ioctl instead!"
> > That's the main problem that you need to push back on here.
> >
> > What is forcing you to put all of this into the kernel in the first
> > place? What's wrong with the userspace network connection/protocol
> > that you have today?
> >
> > Does this mean that we now have to implement all REST apis that people
> > dream up as ioctl interfaces over a hyperv transport? That would be
> > insane.
>
> As far as I understand, the purpose of the driver is to replace a "slow"
> network connection to API endpoint with a "fast" transport over Vmbus. So
> what if instead of implementing this new driver we just use Hyper-V Vsock and
> move API endpoint to the host?

Hi Vitaly,

We looked at Hyper-V Vsock when designing this driver. The problem is that the Hyper-V device model of Vsock can't support the data throughput and scale needed for Blobs. Vsock is mostly used for management tasks.

The usage of Blob in Azure justifies an dedicated VMBUS channel (and sub-channels) for a new VSP/VSC driver.

Thanks,

Long

>
> --
> Vitaly