Re: efinet SNP issue affects iscsi boot

[Michael Chang <mchang@suse.com>]

On Thu, Sep 13, 2018 at 06:06:15PM -0600, Micah Parrish wrote:
> Hi, new subscriber here.  We have a problem with Grub 2 and its use of SNP
> instead of MNP.  Our UEFI driver for a network card parses the relevant DHCP
> options for iSCSI boot, generates an iBFT table, then gets closed by Grub
> when it opens the SNP interface. The driver removes the iBFT table as part
> of normal unload cleanup.  I think this should happen with the Tianocore
> UEFI reference driver as well.  The problem is often masked or does not
> occur when there are multiple network ports enabled.  It occurs with several
> different vendors NICs.
> 
> Possible solutions I see:
> 
> 1. Grub parses the DHCP options and creates its own iBFT.
> 
> 2. Grub copies the already generated iBFT before destroying the interface.
> 
> 3. Grub opens the network interface MNP instead of SNP.
> 
> Although I am a neophyte at grub and UEFI development, I would like to start
> a discussion on possible solutions.  Has anyone else seen this?

For possible solution 3, I managed to work out patch to use MNP but is not
polished, although it survived my testing. If you don't mind and willing to
give it go I will post it here as RFC patch for review.

Thanks,
Michael

> 
> 
> Micah Parrish
> micah.parrish@hpe.com
> Linux OS Engineer
> Hewlett-Packard Enterprise
> 
> 
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