On Fri, 2007-09-21 at 15:42 +1000, David Gibson wrote: > On Thu, Sep 20, 2007 at 10:34:12PM -0500, Hollis Blanchard wrote: > > I seem to have come across a strange bug while doing KVM development. It > > seems that the final tlbwe in finish_tlb (head_44x.S) is actually > > leaking RPN bits into the "attribute" word. > > > > When I set a breakpoint there and press enter on the serial console, I > > see r12=ef600703, which is the physical address of the UART on this chip > > (440EP), plus the correct permission bits at the bottom. > > > > Am I crazy? I'm not really looking to step through that assembly right > > now... Clearly (current) hardware is just ignoring these errant writes, > > but it should be fixed. > > A quick glance at the code suggests this is indeed wrong. Hurrah. > Another reason to rewrite the 44x tlb miss handling.
Just a quick fix would be fine too... ;) I'm just glad it's not a KVM bug, because when I dumped the TLB state and saw bizarre values I was getting really worried. > PS. "errant" and "error" are not cognate, even if the chip doc > writers think so... According to Merriam Webster, errant 2c is "c : behaving wrongly <an errant child>", so I'm OK with it. -- Hollis Blanchard IBM Linux Technology Center _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev