Re: Xen with dom0 pvops on ultra-recent "git tip" kernel on x86_64

[Jeremy Fitzhardinge <jeremy@goop.org>]

Christophe Saout wrote:
> Hello,
>
>   
>> The X server crashes in some I/O port "inb()" command.  Seems like the
>> io permissions aren't correctly passed through or something. (iopl or
>> ioperm or so)  I'll try to debug a bit more later.
>>     
>
> The native Xen kernel has an arch/x86/kernel/ioport-xen.c which calls:
>
> 	HYPERVISOR_physdev_op(PHYSDEVOP_set_iobitmap, &set_iobitmap);
>
> Is this a feature mabye still missing from the paravirtualized Xen?
>
> If yes, what would it take?  A new paravirt call?
>   

Hi Christophe,

Firstly, thanks a lot for trying out the pvops dom0 and doing so much 
debugging on it.  I'm still catching up on my rather daunting email 
backlog - including your torrent of messages - so feel free to remind me 
about/resent anything important which still needs looking at.

I haven't been brave enough to even attempt starting X; there's a lot of 
work to be done if you want to do anything beyond dumb framebuffer.

Anyway, in this case, I definitely haven't added this call, so it will 
need to be done somewhere.  Does it need to be called once at startup, 
or on every context switch?  There may well be a suitable place to hook 
this into already, but we can add a new pvop if its really needed.

    J