On 21.04.2023 16:41, Oleksii wrote: > On Thu, 2023-04-20 at 14:58 +0200, Jan Beulich wrote: >> On 19.04.2023 17:42, Oleksii Kurochko wrote: >>> + * >>> =================================================================== >>> ========= >>> + * Start addr | End addr | Size | VM area >>> description >>> + * >>> =================================================================== >>> ========= >>> + * FFFFFFFFC0000000 | FFFFFFFFC0200000 | 2 MB | Xen >>> + * FFFFFFFFC0200000 | FFFFFFFFC0600000 | 4 MB | FDT >>> + * FFFFFFFFC0600000 | FFFFFFFFC0800000 | 2 MB | Fixmap >> >> These are all L2 slot 511 aiui, which may be worth mentioning >> especially since >> the top bits don't match the top bits further down in the table >> (because of the >> aliasing). > > Than I'll add one more column where I'll put slot number > >> >>> + * .................. unused .................. >> >> This is covering slot 510, which again may be worth mentioning. >> >>> + * 0000003200000000 | 0000007f40000000 | 331 GB | Direct map(L2 >>> slot: 200-509) >>> + * 0000003100000000 | 0000003140000000 | 1 GB | Frametable(L2 >>> slot: 196-197) >> >> 1Gb is, if I'm not mistaken, a single L2 slot. > Yeah, it can be misunderstood. I meant [196, 197), so 197 isn't > included. I'll update the table. > >> >> Also assuming a 32-byte struct page_info (I don't think you'll get >> away with >> less than that, when even Arm32 requires this much), there's a >> mismatch >> between direct map and frame table size: With 4k pages, the scaling >> factor >> would be 128 if I'm not mistaken. So perhaps you really mean 3Gb here >> to >> cover for (slightly more than) the 331Gb of memory you mean to be >> able to >> map? > For RV64 page_info size will be 56-byte and 32-byte for RV32 but you > are right it should 3 Gb in that case what will be enough ( taking into > account both available sizes of page_info structure ).
Since you say "both": I don't expect you will want to use 3Gb for RV32 there? The table is, at least for now, for RV64 / Sv39 only anyway. Jan
