Avi Kivity wrote: > Ingo Molnar wrote: >> * Avi Kivity <[EMAIL PROTECTED]> wrote: >> >> >>>> rmap_write_protect() has a BUG_ON() if a physical address is not >>>> found the the memslot. But this is a possible scenario if a buggy >>>> guest OS loads an invalid or corrupted cr3 value. So exit more >>>> gracefully. >>>> >>> I think a better solution is to detect the invalid cr3 in new_cr3(). >>> That way the entire chain of error returns is avoided. >>> >> >> i'm wondering what the right semantics would be though. Kill the VM >> context? >> >> on a real CPU an invalid cr3 does nothing explicitly (besides being a >> sure way to get a triple fault) - physical memory is always >> accessible, non-present physical memory at most generates an #MCE, >> but is typically just returning 0xff, right? So perhaps keep a >> non-mapped page filled with 0xff and map non-existent RAM to that? >> But then this 'RAM' needs to be made non-writable. > > That's a good solution. I don't see why it has to be made > non-writable -- it has undefined content, and any old value will do. > We have (or maybe had) something like that somewhere.
It probably solves other cases as well, and simplifies error handling elsewhere. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
