On Tue, 22 Nov 2022 at 14:21, Peter Maydell <peter.mayd...@linaro.org> wrote: > > On Mon, 21 Nov 2022 at 19:02, Ard Biesheuvel <a...@kernel.org> wrote: > > > > On Mon, 21 Nov 2022 at 19:51, Peter Maydell <peter.mayd...@linaro.org> > > wrote: > > > > > > On Mon, 21 Nov 2022 at 17:43, Ard Biesheuvel <a...@kernel.org> wrote: > > > > > > > > The LPA2 extension implements 52-bit virtual addressing for 4k and 16k > > > > translation granules, and for the former, this means an additional level > > > > of translation is needed. This means we start counting at -1 instead of > > > > 0 when doing a walk, and so 'level' is now a signed quantity, and should > > > > be typed as such. So turn it from uint32_t into int32_t. > > > > > > > > > > Does this cause any visible wrong behaviour, or is it just > > > a cleanup thing ? > > > > > > > No, 5 level paging is completely broken because of this, given that > > the 'level < 3' tests give the wrong result for (uint32_t)-1 > > Right, thanks. This seems like a bug worth fixing for 7.2. >
Indeed. And the other patch I sent is needed too if you want to run with LPA2 'target/arm: Limit LPA2 effective output address when TCR.DS == 0' In case it is useful, I have a WIP kernel branch here which can be built with 52-bit virtual addressing for 4k or 16k pages. https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=arm64-4k-lpa2 > We should make 'uint32_t startlevel' also an int32_t > for consistency, I think, given that it is also sometimes > negative, though in that case it doesn't get used in any > comparisons so it's not going to cause wrong behaviour. > Indeed. I'll send a v2 and fold that in.