Re: Xen master hangs

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Jul 31, 2015 at 08:58:47AM +0100, Ian Campbell wrote:
> On Thu, 2015-07-30 at 16:32 -0500, Doug Goldstein wrote:
> > 
> > I'm not sure what I can use to identify the system early on. I see the
> > EFI FW vendor and EFI FW revision. I'm not sure if that would be
> > enough. In the case of using that it would likely have to be a range
> > of revisions.
> 
> Is DMI available this early? That's the sort of thing we quirk on today, I
> think (maybe an x86 person could confirm).

There is the SMBIOS table (that is the DMI) that is available during
before we need thse sort of overrides.

It could be implemented but I keep on going back to the valid
point that Jan raised: This is a firmware bug!!

Thought the other solution is to do what Linux does (SetVirtualAddressMap)
which would bypass the firmware bug - by executing these calls
after ExitBootServices has been called - and in virtual address mode
instead of the 1:1. This is just side-stepping the bug.

However the implementation that uses SetVirtualAddressMap
crashes right away - so it would need some work, while the
quirks are not the case.

I will let Jan and Andrew figure out what they want and can spin
some patches later on.
> 
> Ian.