>>> On 27.07.12 at 13:18, Stefano Stabellini <stefano.stabell...@eu.citrix.com> >>> wrote: > On Thu, 26 Jul 2012, Konrad Rzeszutek Wilk wrote: >> 1) All P2M lookups instead of using the __ka address would >> use the __va address. This means we can safely erase from >> __ka space the PMD pointers that point to the PFNs for >> P2M array and be OK. >> 2). Allocate a new array, copy the existing P2M into it, >> revector the P2M tree to use that, and return the old >> P2M to the memory allocate. This has the advantage that >> it sets the stage for using XEN_ELF_NOTE_INIT_P2M >> feature. That feature allows us to set the exact virtual >> address space we want for the P2M - and allows us to >> boot as initial domain on large machines. >> >> So we pick option 2). > > 1) looks like a decent option that requires less code. > Is the problem with 1) that we might want to access the P2M before we > have __va addresses ready?
AIUI 1) has no easy way of subsequently accommodating support for XEN_ELF_NOTE_INIT_P2M (where you almost definitely will want/need to reclaim the originally used VA space - if nothing else, then for forward compatibility with the rest of the kernel). Jan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
