Re: [RFC PATCH 00/13][V3] kexec: A new system call to allow in kernel loading

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, Jun 18, 2014 at 09:52:46AM +0800, Dave Young wrote:
[..]
> > > > Hi, Vivek
> > > > 
> > > > For efi ioremapping case, in 3.15 kernel efi runtime maps will not be saved
> > > > if efi=old_map is used. So you need detect this and fail the kexec file load.
> > > 
> > > Dave,
> > > 
> > > Instead of failing kexec load in case of efi=old_map, I think it will be
> > > better to just not pass runtime map in bootparams. That way user can
> > > pass "noefi" on commandline and kdump should still work.  (Like it works
> > > with user space implementation).
> 
> BTW, in kexec-tools in case old_map it just does not fill efi_info so 2nd kernel
> will automaticlly switch to noefi boot. So do same in kernel make sense as well.

Yep. If old_map is being used, I will not fill efi_info and I will also
not pass efi setup data structure. I think user space does the same.

> 
> In userspace tools we pass acpi_rsdp for kdump noefi case, do you want to add that
> in the kernel loader?

I will not do that in kernel. I will expect user space to pass in
acpi_rsdp=0x on command line.

Thanks
Vivek