On 09/03/2015 20:49, Avi Kivity wrote: >>> >> Yes, and it checked that MAXPHYADDR != 52 before. If you want to set >> only one bit, making that bit 51 makes sense anyway for simplicity, so >> it is still 99.9% academic. Once processors appear with MAXPHYADDR = >> 52, the remaining 0.1% will become more relevant. >> >> The current limit is IIRC 46 or 48 (on Haswell Xeons). > > It will be interesting to have processors with 52 bits of physical > address and 48 bits of virtual address. HIGHMEM for x86_64? Or 5-level > page tables? I wonder why Intel chose exactly 52... HIGHMEM seems more likely than 5-level page tables. Certainly it wouldn't need hacks like Ingo's 4G-4G. > 50 bits == 1 PiB. That's quite an amount of RAM. Not that 64 TiB is not "quite an amount of RAM". :) Paolo -- 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