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Re: PCI Arbiter
Re: PCI Arbiter
Fri, 22 Dec 2017 20:41:14 +0100
Joan Lledó, on dim. 03 déc. 2017 11:21:53 +0100, wrote:
> This is a new version of the PCI arbiter.
Nice work :D
> I tried to run netdde as non-root but gave up because it seemed non-trivial
> me and the time for my thesis is running out. Next are some issues I found:
> - Some network drivers poke IO ports by themselves (See #hurd, 2017-11-23
Yes. Thinking about it, Mach actually provides a way to give a task the
right for a given range of I/O ports (i386_io_perm_cerate), so one could
> - check_kernel() in check_kernel.c is calling get_privileged_ports().
We could make this just return if it's not privileged. Longterm-wise we
want to just drop kernel network drivers anyway.
> Besides, the pci server lacks some features required to run netdde as
> - Provide some way for the client to map device's regions and rom into its
> space. read() + mmap() could be enough for read-only spaces, but probably
> making the server act as a pager is the only good solution.
> (See #hurd, 2017-10-27 ).
Possibly yes. Virtual memory hackers, any opinion on this?
> - Provide libpciaccess and pciutils with a way to poke IO ports as non-root.
> Adding new routines to the PCI interface is an option, or even creating a
> new interface, since poking IO ports is not necessarily related to PCI.
Well, as mentioned above the interface already exists actually :) But
there doesn't exist any arbiter for it in general. I don't think we want
to spend time on doing it for legacy ports, and we should just work on
support in the PCI arbiter: an RPC operation which just returns a port
created with i386_io_perm_create, so the caller can then enable/disable
I/O access to the ranges of ports at will.