On Wed, 29 May 2013, Russ Anderson wrote:
> > What appears to be happening is that your the EFI runtime services code
> > is calling into the EFI boot services code, which is definitely a bug in
> > your firmware because we're at runtime, but we've seen other machines
> > that do similar things so we usually handle it just fine. However, what
> > makes your case different, and the reason you see the above splat, is
> > that it's using the physical address of the EFI boot services region,
> > not the virtual one we setup with SetVirtualAddressMap(). Which is a
> > second firmware bug. Again, we have seen other machines that access
> > physical addresses after SetVirtualAddressMap(), but until now we
> > haven't had any non-optional code that triggered them.
> >
> > The only reason I can see that the offending commit would introduce this
> > problem is because it calls QueryVariableInfo() at boot time. I notice
> > that your machine is an SGI UV one, is there any chance you could get a
> > firmware fix for this? If possible, it would be also good to confirm
> > that it's this chunk of code in setup_efi_vars(),
> >
> > status = efi_call_phys4(sys_table->runtime->query_variable_info,
> > EFI_VARIABLE_NON_VOLATILE |
> > EFI_VARIABLE_BOOTSERVICE_ACCESS |
> > EFI_VARIABLE_RUNTIME_ACCESS, &store_size,
> > &remaining_size, &var_size);
>
> This does trigger the problem. Note that the definition of
> QueryVariableInfo() in the UEFI spec says:
>
> The returned MaximumVariableStorageSize, RemainingVariableStorageSize,
> MaximumVariableSize information may change immediately after the call
> based on other runtime activities including asynchronous error events.
> Also, these values associated with different attributes are not
> additive in nature.
>
> Note the values may be accurate at the point in time when returned,
> but may not be after that.
>
> After the system has transitioned into runtime (after
> ExitBootServices() is called), an implementation may not be able to
> accurately return information about the Boot Services variable store.
> In such cases, EFI_INVALID_PARAMETER should be returned.
>
> It is not clear to me exactly when ExitBootServices() is called.
> Our bios is returning a failing indication on the call.
Yes, but this call is clearly happening way before ExitBootServices() --
see the surrounding code, see for example this in efi_main():
[ ... snip ... ]
setup_efi_vars(boot_params);
setup_efi_pci(boot_params);
status = efi_call_phys3(sys_table->boottime->allocate_pool,
EFI_LOADER_DATA, sizeof(*gdt),
(void **)&gdt);
if (status != EFI_SUCCESS) {
efi_printk("Failed to alloc mem for gdt structure\n");
goto fail;
}
[ ... snip ... ]
We are calling QueryVariableInfo() in setup_efi_vars(), and later on
AllocatePool is being called (through boot table). That'd inherently fail
if we were calling it after ExitBootServices() has happened, but I believe
that call is succeeding on your affected system as well.
--
Jiri Kosina
SUSE Labs
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