David, we're being approached with the situation where a disk driver in the kexec-ed kernel needs memory below 4G in order to perform DMA (e.g. for the swiotlb to be set up). Linux not so long ago invented a two area approach, which doesn't fit with the current single KEXEC_RANGE_MA_CRASH area obtainable via KEXEC_CMD_kexec_get_range.
I see multiple options - do no change at all; the user can deal with this by explicitly specifying an area below 4G via "crashkernel=" - add KEXEC_RANGE_MA_CRASH_LOW - when not asked for a specific address, always allocate the (single) area below 4G if there is enough space - provide a means to request allocating the (single) area below 4G (or perhaps more generically below a certain boundary) without requiring an exact address to be specified Do you have any preference here, or do you see other viable alternatives? Thanks, Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
