Re: [RFC V2 PATCH 8/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Apr 13, 2021 at 11:22:13AM -0400, Tianyu Lan wrote:
> From: Tianyu Lan <Tianyu.Lan@microsoft.com>
> 
> UIO HV driver should not load in the isolation VM for security reason.
> Return ENOTSUPP in the hv_uio_probe() in the isolation VM.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
> ---
>  drivers/uio/uio_hv_generic.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
> index 0330ba99730e..678b021d66f8 100644
> --- a/drivers/uio/uio_hv_generic.c
> +++ b/drivers/uio/uio_hv_generic.c
> @@ -29,6 +29,7 @@
>  #include <linux/hyperv.h>
>  #include <linux/vmalloc.h>
>  #include <linux/slab.h>
> +#include <asm/mshyperv.h>

No driver should be having to add "asm" include files.

>  
>  #include "../hv/hyperv_vmbus.h"
>  
> @@ -241,6 +242,10 @@ hv_uio_probe(struct hv_device *dev,
>  	void *ring_buffer;
>  	int ret;
>  
> +	/* UIO driver should not be loaded in the isolation VM.*/
> +	if (hv_is_isolation_supported())
> +		return -ENOTSUPP;
> +		
>  	/* Communicating with host has to be via shared memory not hypercall */
>  	if (!channel->offermsg.monitor_allocated) {
>  		dev_err(&dev->device, "vmbus channel requires hypercall\n");
> -- 
> 2.25.1
> 

Always run checkpatch.pl on your patches so you do not get grumpy
maintainers telling you to run checkpatch.pl on your patch :(

{sigh}