On 01/16/2009 04:45 PM, Bill Nottingham wrote: > Steffen Maier (maier@xxxxxxxxxxxxxxxxxx) said: >> On s390, udev may also automatically load (network) driver modules >> (except for some hacking required for LCS and CTC). >> >> After loading driver modules, the probing as we are used to on other >> platforms does not happen in the same way and _no_ (network) device >> kernel structures are allocated at this point. We must not touch >> devices which might be meant for another LPAR/VM. Hence, only the user >> can decide which one (or few) of all the available devices should be >> made available to the local Linux instance. Only then, a (network) >> device gets allocated and the remaining configuration (e.g. IP on >> layer 3) may very well be done as on any other hardware platform. > > Not that it's going to get much traction at this stage of s390's lifecycle, > but this seems a fundamental design flaw - why would you trust each > VM with making sure it doesn't step on other VMs' resources? Wouldn't > this best be done in the hypervisor itself? I did not say you cannot do it in a safe way in the hypervisor in case of z/VM or in the I/O configuration of the hardware in case of LPAR. You can do it, some people do it, and then you don't have problems because you might see more than you actually should. Still you might have thousands of devices and have to cope with them. But there are also configurations that "span" devices among different VMs/LPARs for various reasons. >> Yet, I don't think the steps for an actual allocation of a network >> device on s390 should be integrated into NetworkManager. Those steps >> are nothing more than a little pre-init we need on s390 to get our >> devices going and available for e.g. HAL/NetworkManager. It's best to >> code the pre-init at one place in the anaconda package > > No, it should be in udev. anaconda should not have hardware-specific > code. OK, I think I get an initial picture of how this could be. But where from would you get the information which devices to actually allocate which is in turn only known by the user? >> Also, NetworkManager relies on DHCP for e.g. auto-configuring network >> layer addresses. > > NM can use static IP addressess, and we already have code for setting > them up. There's no need for anything s390 specific here. That's what I was trying to say a bit below of what you quoted here. >> At the point where init.c would fork the loader, we would statically >> replace this with an #ifdef and instead fork a stripped down >> linuxrc.s390 which only contains the s390-specific device pre-init >> including the necessary UI. [snip] > That's still doing it wrong... period. The idea is to eventually > get away from a custom init entirely, as I understand it. Any suggestions? Steffen Linux on System z Development IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Martin Jetter Geschäftsführung: Erich Baier Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 _______________________________________________ Anaconda-devel-list mailing list Anaconda-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/anaconda-devel-list
