Re: [PATCH] vhost: Fix vhost_copy_to_user()

[Auger Eric <eric.auger@redhat.com>]

Hi Jason,

On 11/04/18 15:44, Jason Wang wrote:
> 
> 
> On 2018年04月11日 21:30, Eric Auger wrote:
>> vhost_copy_to_user is used to copy vring used elements to userspace.
>> We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC.
>>
>> Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache")
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> This fixes a stall observed when running an aarch64 guest with
>> virtual smmu
>> ---
>>   drivers/vhost/vhost.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>> index bec722e..f44aead 100644
>> --- a/drivers/vhost/vhost.c
>> +++ b/drivers/vhost/vhost.c
>> @@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct
>> vhost_virtqueue *vq, void __user *to,
>>           struct iov_iter t;
>>           void __user *uaddr = vhost_vq_meta_fetch(vq,
>>                        (u64)(uintptr_t)to, size,
>> -                     VHOST_ADDR_DESC);
>> +                     VHOST_ADDR_USED);
>>             if (uaddr)
>>               return __copy_to_user(uaddr, from, size);
> 
> Acked-by: Jason Wang <jasowang@redhat.com>
> 
> Thanks!
> 
> Stable material I think.

yes I think so.

Thanks

Eric