On Wed, Feb 15, 2023 at 03:54:11PM +0100, Jan Beulich wrote: > While the PAE-extended-CR3 VM assist is a 32-bit only concept, it still > applies to guests also when run on a 64-bit hypervisor: The "extended > CR3" format has to be used there as well, to fit the address in the only > 32-bit wide register there. As a result it was a mistake that the check > was never enabled for that case, and was then mistakenly deleted in the > course of removal of 32-bit-Xen code (218adf199e68 ["x86: We can assume > CONFIG_PAGING_LEVELS==4"]). > > Similarly during Dom0 construction kernel awareness needs to be taken > into account, and respective code was again mistakenly never enabled for > 32-bit Dom0 when running on 64-bit Xen (and thus wrongly deleted by > 5d1181a5ea5e ["xen: Remove x86_32 build target"]). > > At the same time restrict enabling of the assist for Dom0 to just the > 32-bit case. Furthermore there's no need for an atomic update there. > > Signed-off-by: Jan Beulich <[email protected]>
Acked-by: Roger Pau Monné <[email protected]> Thanks, Roger.
