On 04/21/2012 08:55 AM, Marcelo Tosatti wrote: >> So this is an example of implicit assumptions which break if you update >> spte without mmu_lock. Certainly there are more cases. :( > > OK, i now see you mentioned a similar case in the document, for > rmap_write_protect. > > More importantly than the particular flush TLB case, the point is > every piece of code that reads and writes sptes must now be aware that > mmu_lock alone does not guarantee stability. Everything must be audited. > Yes, that is true, but it is not hard to audit the code since we only change the spte from read-only to writable, also all information that fast page fault depends on is from spte. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html