Re: [RFC 01/12] Drivers: hv: vmbus: Drop unsupported VMBus devices earlier

From: Wei Liu
Date: Mon Jun 24 2024 - 03:11:22 EST


On Mon, Jun 03, 2024 at 10:09:29PM -0700, mhkelley58@xxxxxxxxx wrote:
> From: Michael Kelley <mhklinux@xxxxxxxxxxx>
>
> Because Hyper-V doesn't know ahead-of-time what operating system will be
> running in a guest VM, it may offer to Linux guests VMBus devices that are
> intended for use only in Windows guests. Currently in Linux, VMBus
> channels are created for these devices, and they are processed by
> vmbus_device_register(). While nothing further happens because no matching
> driver is found, the channel continues to exist.
>
> To avoid having the spurious channel, drop such devices immediately in
> vmbus_onoffer(), based on identifying the device in the
> vmbus_unsupported_devs table. If Hyper-V should issue a rescind request
> for the device, no matching channel will be found and the rescind will
> also be ignored.
>
> Since unsupported devices are dropped early, the check for unsupported
> devices in hv_get_dev_type() is redundant. Remove it.
>
> Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx>

Acked-by: Wei Liu <wei.liu@xxxxxxxxxx>