Re: [PATCH] vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition

From: Michael S. Tsirkin
Date: Mon Sep 03 2018 - 23:11:15 EST


On Tue, Sep 04, 2018 at 11:08:40AM +0800, Jason Wang wrote:
>
>
> On 2018å09æ04æ 10:22, Michael S. Tsirkin wrote:
> > On Mon, Sep 03, 2018 at 08:59:13PM +0300, Gleb Fotengauer-Malinovskiy wrote:
> > > The _IOC_READ flag fits this ioctl request more because this request
> > > actually only writes to, but doesn't read from userspace.
> > > See NOTEs in include/uapi/asm-generic/ioctl.h for more information.
> > >
> > > Fixes: 429711aec282 ("vhost: switch to use new message format")
> > > Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@xxxxxxxxxxxx>
> > Hmm it does make sense, and it's not too late to fix this up.
> > Jason, what's your take on this? Was _IOW intentional?
>
> My bad, not intentional. And I agree that fixing this is not too late.
>
> So
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>


OK then

Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

> >
> > > ---
> > > include/uapi/linux/vhost.h | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > > index b1e22c40c4b6..84c3de89696a 100644
> > > --- a/include/uapi/linux/vhost.h
> > > +++ b/include/uapi/linux/vhost.h
> > > @@ -176,7 +176,7 @@ struct vhost_memory {
> > > #define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
> > > #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
> > > -#define VHOST_GET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x26, __u64)
> > > +#define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
> > > /* VHOST_NET specific defines */
> > >
> > > --
> > > glebfm