On 2025/7/7 21:40, Stefano Garzarella wrote:
> On Sun, Jul 06, 2025 at 12:36:29PM +0800, Xuewei Niu wrote:
>
> Again, this patch should have `From: Dexuan Cui <decui@xxxxxxxxxxxxx>` on first line, and this is done automatically by `git format-patch` (or others tools) if the author is the right one in your branch.
> I'm not sure what is going on on your side, but you should avoid to reset the original author.
> Applying this patch we will have:
>
> commit ed36075e04ecbb1dd02a3d8eba5bfac6469d73e4
> Author: Xuewei Niu <niuxuewei97@xxxxxxxxx>
> Date: Sun Jul 6 12:36:29 2025 +0800
>
> hv_sock: Return the readable bytes in hvs_stream_has_data()
>
> This is not what we want, right?
>
>> When hv_sock was originally added, __vsock_stream_recvmsg() and
>> vsock_stream_has_data() actually only needed to know whether there
>> is any readable data or not, so hvs_stream_has_data() was written to
>> return 1 or 0 for simplicity.
>>
>> However, now hvs_stream_has_data() should return the readable bytes
>> because vsock_data_ready() -> vsock_stream_has_data() needs to know the
>> actual bytes rather than a boolean value of 1 or 0.
>>
>> The SIOCINQ ioctl support also needs hvs_stream_has_data() to return
>> the readable bytes.
>>
>> Let hvs_stream_has_data() return the readable bytes of the payload in
>> the next host-to-guest VMBus hv_sock packet.
>>
>> Note: there may be multpile incoming hv_sock packets pending in the
>> VMBus channel's ringbuffer, but so far there is not a VMBus API that
>> allows us to know all the readable bytes in total without reading and
>> caching the payload of the multiple packets, so let's just return the
>> readable bytes of the next single packet. In the future, we'll either
>> add a VMBus API that allows us to know the total readable bytes without
>> touching the data in the ringbuffer, or the hv_sock driver needs to
>> understand the VMBus packet format and parse the packets directly.
>>
>> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
>
> Your S-o-b was fine here, I was talking about the author.
I misunderstood the meaning of author. Sorry about that.
Will update this in v6.
Thanks,
Xuewei
> Thanks,
> Stefano
>
>> ---
>> net/vmw_vsock/hyperv_transport.c | 17 ++++++++++++++---
>> 1 file changed, 14 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
>> index 31342ab502b4fc35feb812d2c94e0e35ded73771..432fcbbd14d4f44bd2550be8376e42ce65122758 100644
>> --- a/net/vmw_vsock/hyperv_transport.c
>> +++ b/net/vmw_vsock/hyperv_transport.c
>> @@ -694,15 +694,26 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
>> static s64 hvs_stream_has_data(struct vsock_sock *vsk)
>> {
>> struct hvsock *hvs = vsk->trans;
>> + bool need_refill;
>> s64 ret;
>>
>> if (hvs->recv_data_len > 0)
>> - return 1;
>> + return hvs->recv_data_len;
>>
>> switch (hvs_channel_readable_payload(hvs->chan)) {
>> case 1:
>> - ret = 1;
>> - break;
>> + need_refill = !hvs->recv_desc;
>> + if (!need_refill)
>> + return -EIO;
>> +
>> + hvs->recv_desc = hv_pkt_iter_first(hvs->chan);
>> + if (!hvs->recv_desc)
>> + return -ENOBUFS;
>> +
>> + ret = hvs_update_recv_data(hvs);
>> + if (ret)
>> + return ret;
>> + return hvs->recv_data_len;
>> case 0:
>> vsk->peer_shutdown |= SEND_SHUTDOWN;
>> ret = 0;
>>
>> --
>> 2.34.1
>>
