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Message-ID: <36c12486-57d4-c11d-474f-f26a7de8e59a@linux.intel.com>
Date:   Tue, 13 Sep 2022 10:12:06 +0800
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Subject: Re: [PATCH] net/ncsi: Add Intel OS2BMC OEM command
To:     Paul Fertser <fercerpav@gmail.com>
Cc:     Samuel Mendoza-Jonas <sam@mendozajonas.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org
References: <20220909025716.2610386-1-jiaqing.zhao@linux.intel.com>
 <YxrWPfErV7tKRjyQ@home.paul.comp>
 <8eabb29b-7302-d0a2-5949-d7aa6bc59809@linux.intel.com>
 <Yxrun9LRcFv2QntR@home.paul.comp>
Content-Language: en-US
From:   Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
In-Reply-To: <Yxrun9LRcFv2QntR@home.paul.comp>
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On 2022-09-09 15:43, Paul Fertser wrote:
> Hello,
> 
> On Fri, Sep 09, 2022 at 03:34:53PM +0800, Jiaqing Zhao wrote:
>>> Can you please outline some particular use cases for this feature?
>>>
>> It enables access between host and BMC when BMC shares the network connection
>> with host using NCSI, like accessing BMC via HTTP or SSH from host. 
> 
> Why having a compile time kernel option here more appropriate than
> just running something like "/usr/bin/ncsi-netlink --package 0
> --channel 0 --index 3 --oem-payload 00000157200001" (this example uses
> another OEM command) on BMC userspace startup?
> 

Using ncsi-netlink is one way, but the package and channel id is undetermined
as it is selected at runtime. Calling the netlink command on a nonexistent
package/channel may lead to kernel panic.

Why I prefer the kernel option is that it applies the config to all ncsi
devices by default when setting up them. This reduces the effort and keeps
compatibility. Lots of things in current ncsi kernel driver can be done via
commands from userspace, but I think it is not a good idea to have a driver
resides on both kernel and userspace.