Re: [regression, bisected] x86: efi: Pass boot services variableinfo to runtime code

[Jiri Kosina]

On Fri, 31 May 2013, Russ Anderson wrote:

> OK.  I get nvram looks full due to lack of garbage collection
> on some systems.  Does QueryVariableInfo (at runtime) tell you
> it is full?  Is the problem that it says it is full when it
> is not, or does not tell you it is full when it is?

We are trying to count the size occupied by existing UEFI variables. 
QueryVariableInfo() called from runtime environment doesn't give a full 
picture, as it doesn't provide information about boot-only variables.

Hence the patch.

> > up the size of the variables ourselves, but that only gives us the value 
> > for runtime-visible variables. We also need to know how much space is 
> > used by variables that are only visible during boot,
> 
> Is it valid to assume that only the kernel writes to nvram at
> runtime?  

Well, mostly yes. But if the kernel doesn't know what the initial state 
is, it can't count the size properly.

> > > Which means the previous patch(es) that caused the bricking should
> > > get pulled, too.
> > 
> > There are no patches that cause the bricking.
> 
> I thought that was the problem you were trying to avoid.

The problem that needs to be avoided is machines turning into bricks if 
EFI storage nvram is getting full.

-- 
Jiri Kosina
SUSE Labs
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