From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out28-145.mail.aliyun.com (out28-145.mail.aliyun.com [115.124.28.145]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 867821401B; Tue, 8 Jul 2025 05:17:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.28.145 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751951866; cv=none; b=cHoPnBmQv4ev3KqYCTzHDT0va59aBxoqurdMIQ9WtYPL9xpjjYbKvoZ+ZkAzsKej7VCLfL6os5Vm3H/jZX6EAoNQO0QuCF7LRwVqbfqkVF6ikt12NtEx2eX4jA9veAPWBaEf2HGbiyC4wSKMz+wak3ESeRxvEjcjKR40PthqG84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751951866; c=relaxed/simple; bh=59y7qEw4GpHqR9V5yVAvN9k1VJ4Mks0dolgkvU2v08Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rCRm/Rkgg5wrFE9ZxItkp2FJmz0nL2940YocabN84cBJ7P8a3CuByNyPShm2gTZFYRwcoaPtX76E4UUvPjHHKbRBS8GLVdGZ4vG7f6YpE682VhzI8MaSLfur+P6MYy8nDuN36toTKbSiPXO0ZZKgkO1gIJX6OJFBD8LiqwQExvo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=antgroup.com; spf=pass smtp.mailfrom=antgroup.com; dkim=pass (1024-bit key) header.d=antgroup.com header.i=@antgroup.com header.b=fQ1NQV0g; arc=none smtp.client-ip=115.124.28.145 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=antgroup.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=antgroup.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=antgroup.com header.i=@antgroup.com header.b="fQ1NQV0g" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=antgroup.com; s=default; t=1751951858; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=ll42IxvjGlWNCvhre5iXoxCnMkwXG5zTYn4NRTnJbTc=; b=fQ1NQV0gOfvv4zK1Fip/DQ6VhcY4HG/Ffc7BrIqkhhSwsKjLJYY6fZcYqlreNmaHfXJkDFcgX9ObKGKTvUEavXPWhAwCmG584LtKL3TKw1RjNujiKSfha9uCLN3xzxnqthJ3cFIa2mPhTMdJ/IOuzTpAoKzy3ROm/ukwZKgEzbw= Received: from 30.172.244.77(mailfrom:niuxuewei.nxw@antgroup.com fp:SMTPD_---.dhG9apK_1751951856 cluster:ay29) by smtp.aliyun-inc.com; Tue, 08 Jul 2025 13:17:37 +0800 Message-ID: Date: Tue, 8 Jul 2025 13:17:36 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v5 1/4] hv_sock: Return the readable bytes in hvs_stream_has_data() To: Stefano Garzarella , Xuewei Niu Cc: "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, fupan.lfp@antgroup.com References: <20250706-siocinq-v5-0-8d0b96a87465@antgroup.com> <20250706-siocinq-v5-1-8d0b96a87465@antgroup.com> Content-Language: en-US From: Xuewei Niu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 2025/7/7 21:42, Stefano Garzarella wrote: > On Sun, Jul 06, 2025 at 12:36:29PM +0800, Xuewei Niu wrote: >> 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 > > s/multpile/multiple Will do. Thanks, Xuewei >> 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 >> --- >> 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 >>