[Xen-devel] kexec's v1 compatibility code

["Jan Beulich" <JBeulich@xxxxxxxx>]

David,

now that we're putting Xen 4.4.x underneath an older distro (SLE11)
we've got to see that kexec doesn't work there. Initial investigation
of our kexec person revealed that the destinations attempted to be
written to by kexec_reloc()'s code following the is_source and
is_zero labels have no mappings in the kexec page tables. Comparing
kexec_do_load_v1() with kexec_load() I wonder whether the former
isn't simply lacking a call to kimage_load_segments().

He worked around this (I haven't seen the code yet that he used)
to then find that the dump kernel (other than an "ordinary" kexec
one) also expects at least the low 640k to be mapped. He's
suggesting that Linux'es kexec code sets up an identity mapping of
all memory, and that we should do the same. I can't say I'm
convinced of this though, as it seems bogus to me that the dump
kernel should depend on anything beyond a bare minimum
environment it is being handed control in; I would instead expect
the crash kernel to be responsible for any such specific needs.

May I also ask whether that compatibility code got tested?

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel