[dpdk-stable] patch 'vhost: fix payload size of reply' has been queued to LTS release 16.11.9

[Ilya Maximets]

Hi,
I'm not sure if we need to backport this change because
sending the payload doesn't cause any issues in current
QEMU implementation.
Anyway, If you want to do that, the change should be done
like this (and some comments merge will be needed):

---
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 04c92ceb3..44b792420 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1114,7 +1114,7 @@ vhost_user_msg_handler(int vid, int fd)
                vhost_user_set_log_base(dev, &msg);
 
                /* it needs a reply */
-               msg.size = sizeof(msg.payload.u64);
+               msg.size = 0;
                send_vhost_message(fd, &msg);
                break;
        case VHOST_USER_SET_LOG_FD:
---

This is because before commit
e951355ffcae ("vhost: make message handling functions prepare the reply")
replies was handled in-place by the caller function.

Best regards, Ilya Maximets.

On 29.10.2018 15:53, Luca Boccassi wrote:
> Hi,
> 
> FYI, your patch has been queued to LTS release 16.11.9
> 
> Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
> It will be pushed if I get no objections before 10/31/18. So please
> shout if anyone has objections.
> 
> Also note that after the patch there's a diff of the upstream commit vs the patch applied
> to the branch. If the code is different (ie: not only metadata diffs), due for example to
> a change in context or macro names, please double check it.
> 
> Thanks.
> 
> Luca Boccassi
> 
> ---
>>From 2fb95d184bf2b7715c9e2696059d41fd044a2d88 Mon Sep 17 00:00:00 2001
> From: Maxime Coquelin <maxime.coquelin at redhat.com>
> Date: Fri, 12 Oct 2018 14:40:32 +0200
> Subject: [PATCH] vhost: fix payload size of reply
> 
> [ upstream commit 57b4d90b5893db2678ca3e28c50e1fcd37bb9b91 ]
> 
> QEMU doesn't expect any payload for the reply of
> VHOST_USER_SET_LOG_BASE request, so don't send any.
> Note that the Vhost-user specification isn't clear about
> it and would need to be fixed.
> 
> Fixes: 54f9e32305d4 ("vhost: handle dirty pages logging request")
> 
> Reported-by: Ilya Maximets <i.maximets at samsung.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> Acked-by: Ilya Maximets <i.maximets at samsung.com>
> ---
>  lib/librte_vhost/vhost_user.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index f3b286e72..a88f19aae 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -911,6 +911,12 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
>  	dev->log_base = dev->log_addr + off;
>  	dev->log_size = size;
>  
> +	/*
> +	 * The spec is not clear about it (yet), but QEMU doesn't expect
> +	 * any payload in the reply.
> +	 */
> +	msg->size = 0;
> +
>  	return 0;
>  }
>  
>