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Date:   Mon, 9 Aug 2021 15:56:15 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Tony Nguyen <anthony.l.nguyen@intel.com>
Cc:     davem@davemloft.net,
        Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>,
        netdev@vger.kernel.org, Gurucharan G <gurucharanx.g@intel.com>,
        Konrad Jankowski <konrad0.jankowski@intel.com>
Subject: Re: [PATCH net 1/4] ice: Prevent probing virtual functions
Message-ID: <20210809155615.193bd6c8@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <20210809171402.17838-2-anthony.l.nguyen@intel.com>
References: <20210809171402.17838-1-anthony.l.nguyen@intel.com>
        <20210809171402.17838-2-anthony.l.nguyen@intel.com>
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On Mon,  9 Aug 2021 10:13:59 -0700 Tony Nguyen wrote:
> The userspace utility "driverctl" can be used to change/override the
> system's default driver choices. This is useful in some situations
> (buggy driver, old driver missing a device ID, trying a workaround,
> etc.) where the user needs to load a different driver.
> 
> However, this is also prone to user error, where a driver is mapped
> to a device it's not designed to drive. For example, if the ice driver
> is mapped to driver iavf devices, the ice driver crashes.
> 
> Add a check to return an error if the ice driver is being used to
> probe a virtual function.

This seems too selective. Also drivers should not trust the HW is sane
and crash the kernel. Please fix the crashes and fail probe gracefully
in all cases without resorting to duct tape.