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

[Jason Wang <jasowang@redhat.com>]

On 2018年09月04日 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@altlinux.org>
> 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@redhat.com>

>
>> ---
>>   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