[PATCH v2 1/2] drm/vmwgfx: add local DRM_AUTH check for PRIME TO/FROM HANDLE

[Deepak Singh Rawat]

Hi Emil,

Thanks for doing this. Looks good to me. By the way I think Thomas had
a patch to get rid of legacy locking mechanism. I don't know when it
will go upstream. With that we no need for the below check.

Reviewed-by: Deepak Rawat <drawat at vmware.com>

On Fri, 2019-08-02 at 18:01 +0100, Emil Velikov wrote:
> From: Emil Velikov <emil.velikov at collabora.com>
> 
> Realistically no drivers, but vmwgfx care about the DRM_AUTH flag
> here.
> 
> Follow-up work in this driver will properly isolate primary clients
> from
> different master realms, thus we'll no longer need to parse _any_
> ioctl
> flags.
> 
> Until that work lands, add a local workaround.
> 
> v2: Use bitwise or (Deepak)
> 
> Cc: VMware Graphics <linux-graphics-maintainer at vmware.com>
> Cc: Thomas Hellstrom <thellstrom at vmware.com>
> Cc: Deepak Singh Rawat <drawat at vmware.com>
> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
> ---
> I'd like to merge this and the next patch hrough the drm-misc tree.
> Ack
> and rb are appreciated.
> 
> Thanks
> Emil
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index cd0d49d8a8da..53afb1d597e8 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -1134,6 +1134,15 @@ static long vmw_generic_ioctl(struct file
> *filp, unsigned int cmd,
>  	} else if (!drm_ioctl_flags(nr, &flags))
>  		return -EINVAL;
>  
> +	/*
> +	 * Little workaround until the vmwgfx patches providing
> isolation of
> +	 * primary clients from different master realms land.
> +	 * With that work, we'll no longer need to parse _any_ ioctl
> flags.
> +	 */
> +	if (nr == 0x2d /* DRM_IOCTL_PRIME_HANDLE_TO_FD */ ||
> +	    nr == 0x2e /* DRM_IOCTL_PRIME_FD_TO_HANDLE */)
> +		flags |= DRM_AUTH;
> +
>  	vmaster = vmw_master_check(dev, file_priv, flags);
>  	if (IS_ERR(vmaster)) {
>  		ret = PTR_ERR(vmaster);