On 08/01/2020 11:23, Jan Beulich wrote: >>> This would then also ease shrinking the build >>> time mappings further, e.g. to the low 1Mb (instead of touching >>> several of the places you touch now, it would again mainly be an >>> adjustment to BOOTSTRAP_MAP_BASE, alongside the assembly file >>> changes needed). >> ... as you correctly identify here, it is a property of the prebuilt >> tables (in l?_identmap[]), not a property of where we chose to put the >> dynamic boot mappings (in the l?_bootmap[]). Another change (blocked >> behind the above bug) moves BOOTSTRAP_MAP_BASE to be 1G to reduce the >> chance of an offset from a NULL pointer hitting a present mapping. > Right, BOOTSTRAP_MAP_BASE was (ab)used for a 2nd purpose. But this > would better be dealt with by introducing a new manifest constant > (e.g. PREBUILT_MAP_LIMIT) instead of open-coding 2Mb everywhere.
I'm hoping to get rid of even this, (although it is complicated by CONFIG_VIDEO's blind use of the legacy VGA range). > Plus there's (aiui) a PREBUILT_MAP_LIMIT <= BOOTSTRAP_MAP_BASE > requirement, which would better be verified (e.g. by a BUILD_BUG_ON()) > then. Is there? I don't see a real connection between the two, even in this patch. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
