On 11/20/2014 01:40 PM, Peter Maydell wrote: > On 20 November 2014 18:35, Mario Smarduch <m.smarduch@xxxxxxxxxxx> wrote: >> I think beyond consistency, there should be no double mappings with >> conflicting attributes at any time or CPU state is undefined. > > The situation is not so bleak as this. See section B2.9 "Mismatched > memory attributes" in the ARMv8 ARM ARM (DDI0487A.d), which lays > out in some detail what the results of mismatched attributes are > (generally, you lose ordering or coherency guarantees you might > have hoped to have). They're not pretty, but it's not as bad > as completely UNPREDICTABLE behaviour. Quick side note that I did raise exactly this issue with the ARM Architecture team several years ago (that of missmatched memory attributes between a guest and hypervisor) and it is a known concern. I'm personally concerned about a couple of things that I won't go into here but will followup on what the longer term plan might be. Jon. -- 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
