I agree with (1), vmx is not ready for nix yet. as for (2), I'll take a slight change: the goal is to remove nix as an independent entity, and subsume it in other plan 9 kernels (I prefer 9front at this point)
Big picture, NIX could be a build option for 9front, or a branch in 9front; something like that. It makes no sense to keep NIX as its own thing, so much has improved in plan 9 in 14 years. I looked into it and it would turn into a lot of duplicate work, to no good effect. On Wed, Jan 29, 2025 at 5:51 AM <tlaro...@kergis.com> wrote: > It seems to me that the best course, for now, is the following: > > 1) [Using qemu or booting the kernel on baremetal] Try and correct > Nix, in its present state, to achieve a running Nix, with 9front, for > objtype==amd64; > > 2) Once 1) is achieved, start cleaning (then, at this moment, the mps > stuff could be revised) and reorganizing code to clearly segregate > Machine Independent (M.I.) and Machine Dependent (M.D.), so that > porting Nix to other archs be possible. > > And concurrently, during either step, document... > > On Tue, Jan 28, 2025 at 04:02:11PM -0800, Ron Minnich wrote: > > btw, if you > > acid 9pc64 > > you can paste this right into acid > > src(0xfffffffff011cdee); // dumpstack+0x10 > > src(0xfffffffff013d50f); // panic+0x133 > > src(0xfffffffff0116a3b); // KADDR+0x55 > > src(0xfffffffff012fe55); // sigsearch+0xc8 > > src(0xfffffffff012fec9); // mpsinit+0x14 > > src(0xfffffffff011622a); // main+0x30b > > src(0xfffffffff0110204); // ndnr > > and see the source. > > > > Also, the ndnr is a jmk-ism: it means "no deposit, no return" > > > > so, let's see, I can't tell if we went over this before. > > What is KADDR and KADDR2? They relate to TMFM, another jmk-ism I > > believe: Too Many F-ing Megabytes, where too many is "more than 2G" -- > > why 2G? well ... > > > > basically, amd64, like lots of things (risc-v) uses this one simple > > trick: if you sign-extend a 32-bit pointer, you get something anchored > > either at the top 2G (kernel va) or the low 2G (user code). > > > > i.e. 0x80000000 -> 0xffffffff_80000000 -> this is convenient. You can > > use 32-bit pointers for lots of things, and, since the amd64 is a > > pretty half-way 64-bit CPU (lots of 64-bit instructions only > > completely work with RAX), this is helpful. > > > > And it works great until you get CPUs with TMFM. Then you need to > > split memory up: > > physical 0 -> 2 Gb becomes virtual 0xfffffff_80000000 > > physical 2Gb and up becomes ... fffffe0000000000 > > Why fffffe0000000000? the first amd64 only had something like 41(?) > > bits of virtual address:there's this giant hole in the middle,and > > kernel virtual HAD to start at that address -- 64 bits - whatever gets > > you to 23 bits. [I can't find the actual documents on this, I am out > > of time to look, so you'll need to fill in my likely errors here] > > It's a hardware mandate from opteron land. > > > > OK, so KADDR2 is fffffe0000000000, and that error is saying code > > called KADDR2 with something that's not in KADDR2. That va > > fffffffffffffc00 is in the low 2GiB physical, which is KADDR. > > > > This is a side effect of the real problem: you don't have the table it > > wants. So you need to fix that, OR, start using qemu for your testing. > > > > I hope I did not mess the details up too much here.... > > > > On Tue, Jan 28, 2025 at 1:24?PM ron minnich <rminn...@gmail.com> wrote: > > > > > > I'd be happier to remove the mps dependency actually. the mps is long > dead. But that's a bigger story. > > > > > > > > > On Tue, Jan 28, 2025 at 11:24?AM Paul Lalonde < > paul.a.lalo...@gmail.com> wrote: > > >> > > >> Ah, that's the code path that sent me to QEMU. > > >> Vmx doesn't have any MP tables, which leads to this fault in mpsinit. > > >> Ron provided this minimal one for me, which I think we could learn > from to adapt into vmx. The hacky version of pointing the code directly at > something like this baked in didn't excite me. > > >> > > >> 50 43 4D 50 ; "PCMP" > > >> 00 00 ; Table Length (placeholder) > > >> 04 ; Spec Revision > > >> 00 ; Checksum (placeholder) > > >> 42 4F 43 48 53 43 50 55 ; "BOCHSCPU" > > >> 30 2E 31 20 20 20 20 20 20 20 20 ; "0.1 " > > >> 00 00 00 00 ; OEM Table Pointer > > >> 00 00 ; OEM Table Size > > >> 14 00 ; Entry Count (2 CPUs + 18 = 20, > little-endian) > > >> 00 00 E0 FE ; Local APIC Address (0xfee00000) > > >> 00 00 ; Ext Table Length > > >> 00 ; Ext Table Checksum > > >> 00 ; Reserved > > >> > > >> On Tue, Jan 28, 2025 at 11:15?AM <tlaro...@kergis.com> wrote: > > >>> > > >>> On Tue, Jan 28, 2025 at 09:18:29AM -0800, Paul Lalonde wrote: > > >>> > ktrace can generate a stack for you from that dump. The line > starting with > > >>> > "ktrace" is the command line (you might change 9k8cpu to the path > to the > > >>> > kernel file in you're not in the directory where you built it). > > >>> > Then the following lines up to but not including the "cpu0: > exiting" can be > > >>> > dropped into ktrace's stdin to have it generate a stack trace. > You'll need > > >>> > to add the ^d at the end if you're cut-and-pasting. > > >>> > > > >>> > Though it looks like it's just triggering the page fault trap on > that > > >>> > 0xfffffffffffffc00 address, which itself looks like a victim of > > >>> > sign-extension. So back up to the fault and find the source of > that > > >>> > address? > > >>> > > >>> Yes: > > >>> > > >>> src(0xfffffffff011cdee); // dumpstack+0x10 > > >>> src(0xfffffffff013d50f); // panic+0x133 > > >>> src(0xfffffffff0116a3b); // KADDR+0x55 > > >>> src(0xfffffffff012fe55); // sigsearch+0xc8 > > >>> src(0xfffffffff012fec9); // mpsinit+0x14 > > >>> src(0xfffffffff011622a); // main+0x30b > > >>> src(0xfffffffff0110204); // ndnr > > >>> > > >>> this doesn't tell me much more than what I knew already: it panics in > > >>> mpsinit, calling KADDR in map.c. > > >>> > > >>> During my next wandering under Nix, I will try to track back from > > >>> where the offending address is taken or with what it is constructed. > > >>> > > >>> > > > >>> > On Tue, Jan 28, 2025 at 9:09?AM <tlaro...@kergis.com> wrote: > > >>> > > > >>> > > On Tue, Jan 28, 2025 at 07:49:02AM -0800, Paul Lalonde wrote: > > >>> > > > Do you have a stack for the assert, from the ktrace? > > >>> > > > > > >>> > > > > >>> > > Yes, and I was wrong: it fails relatively "late" in main.c: at > > >>> > > mpsinit. > > >>> > > > > >>> > > Here is the info (I added a bunch of print() before each > function call > > >>> > > to know where it stumbled upon an incorrect address): > > >>> > > > > >>> > > term% nix/test_vmx > > >>> > > > > >>> > > NIX > > >>> > > mmunit...mmuinit: vmstart 0xfffffffff0000000 vmunused > 0xfffffffff023d000 > > >>> > > vmunmapped 0xfffffffff0400000 vmend 0xfffffffff4000000 > > >>> > > sys->pd 0x108003 0x108023 > > >>> > > cpu0: mmu l3 pte 0xfffffffff0106ff8 = 107023 > > >>> > > cpu0: mmu l2 pte 0xfffffffff0107ff8 = 108023 > > >>> > > cpu0: mmu l1 pte 0xfffffffff0108c00 = e3 > > >>> > > cpu0: mmu l1 pte 0xfffffffff0108c00 = e3 > > >>> > > ioinit... multibootmemassert... kbdinit... meminit...asm: addr > > >>> > > 0x0000000004000000 end 0x0000000004000000 type 1 size 0 > > >>> > > cm 0: addr 0x4000000 npage 0 > > >>> > > 0 0 0 > > >>> > > npage 0 upage 0 kpage 16384 > > >>> > > confinit... archinit... mallocinit...base 0xfffffffff023d000 ptr > > >>> > > 0xfffffffff023d000 nunits 4047617 > > >>> > > acpiinit... umeminit... trapinit... printinit... i8259init... > procinit... > > >>> > > mpsinit...panic: cpu0: map.c:KADDR() passed addr > fffffffffffffc00 >= > > >>> > > fffffe0000000000 > > >>> > > panic: cpu0: map.c:KADDR() passed addr fffffffffffffc00 >= > fffffe0000000000 > > >>> > > > > >>> > > dumpstack > > >>> > > ktrace 9k8cpu 0xfffffffff011cdee 0xfffffffff0105d58 > > >>> > > estackx 0xfffffffff0106000 > > >>> > > 0xfffffffff0105c70=0xfffffffff0105da8 > > >>> > > 0xfffffffff0105c78=0xfffffffff011cb91 > > >>> > > 0xfffffffff0105c80=0xfffffffff0105c98 > > >>> > > 0xfffffffff0105c98=0xfffffffff013cff7 > > >>> > > 0xfffffffff0105cb0=0xfffffffff0105cd0 > > >>> > > 0xfffffffff0105cc0=0xfffffffff0105ea7 > > >>> > > 0xfffffffff0105cc8=0xfffffffff0105df3 > > >>> > > 0xfffffffff0105ce0=0xfffffffff013d14d > > >>> > > 0xfffffffff0105d08=0xfffffffff0105d90 > > >>> > > 0xfffffffff0105d28=0xfffffffff011cdee > > >>> > > 0xfffffffff0105d30=0xfffffffff0105da8 > > >>> > > 0xfffffffff0105d40=0xfffffffff0105d58 > > >>> > > 0xfffffffff0105d48=0xfffffffff0105da8 > > >>> > > 0xfffffffff0105d50=0xfffffffff011cdee > > >>> > > 0xfffffffff0105d58=0xfffffffff011cb99 > > >>> > > 0xfffffffff0105d68=0xfffffffff013d50f > > >>> > > 0xfffffffff0105d88=0xfffffffff0105ed0 > > >>> > > 0xfffffffff0105d90=0xfffffffff013cff7 > > >>> > > 0xfffffffff0105d98=0xfffffffff0105db5 > > >>> > > 0xfffffffff0105e08=0xfffffffff013d1b8 > > >>> > > 0xfffffffff0105e10=0xfffffffff0105e00 > > >>> > > 0xfffffffff0105e20=0xfffffffff0105ea3 > > >>> > > 0xfffffffff0105e28=0xfffffffff0105e98 > > >>> > > 0xfffffffff0105e38=0xfffffffff013d1b8 > > >>> > > 0xfffffffff0105e40=0xfffffffff0105e98 > > >>> > > 0xfffffffff0105e60=0xfffffffff013d217 > > >>> > > 0xfffffffff0105e68=0xfffffffff015d9c9 > > >>> > > 0xfffffffff0105e80=0xfffffffff0105fb8 > > >>> > > 0xfffffffff0105e90=0xfffffffff015d5d9 > > >>> > > 0xfffffffff0105ea8=0xfffffffff0105ed0 > > >>> > > 0xfffffffff0105ec0=0xfffffffff0116a3b > > >>> > > 0xfffffffff0105ef8=0xfffffffff012fe55 > > >>> > > 0xfffffffff0105f08=0xfffffffff01a1afa > > >>> > > 0xfffffffff0105f10=0x0000000000000004 > > >>> > > 0xfffffffff0105f18=0x0000000000000046 > > >>> > > 0xfffffffff0105f20=0xfffffffff00fffd9 > > >>> > > 0xfffffffff0105f28=0x0000000000000006 > > >>> > > 0xfffffffff0105f30=0xfffffffff015d5d9 > > >>> > > 0xfffffffff0105f38=0xfffffffff0000400 > > >>> > > 0xfffffffff0105f40=0x0000000000000000 > > >>> > > 0xfffffffff0105f48=0xfffffffff012fec9 > > >>> > > 0xfffffffff0105f50=0xfffffffff01a1aff > > >>> > > 0xfffffffff0105f58=0x0000000000000208 > > >>> > > 0xfffffffff0105f60=0x0000000000000124 > > >>> > > 0xfffffffff0105f68=0xfffffffff01149d0 > > >>> > > 0xfffffffff0105f70=0x0000000000000006 > > >>> > > 0xfffffffff0105f78=0xfffffffff0114ba7 > > >>> > > 0xfffffffff0105f80=0xfffffffff0227510 > > >>> > > 0xfffffffff0105f88=0xffffffff00000000 > > >>> > > 0xfffffffff0105f90=0x0000000000000000 > > >>> > > 0xfffffffff0105f98=0xfffffffff0105fb8 > > >>> > > 0xfffffffff0105fa0=0x0000000bf0116b0d > > >>> > > 0xfffffffff0105fa8=0xfffffffff011622a > > >>> > > 0xfffffffff0105fb0=0xffffffff00000400 > > >>> > > 0xfffffffff0105fb8=0xffffffff00000000 > > >>> > > 0xfffffffff0105fc0=0x0000000000000000 > > >>> > > 0xfffffffff0105fc8=0x0000000000000000 > > >>> > > 0xfffffffff0105fd0=0x0000000000000000 > > >>> > > 0xfffffffff0105fd8=0x0000000000000000 > > >>> > > 0xfffffffff0105fe0=0x0000000000000000 > > >>> > > 0xfffffffff0105fe8=0xfffffffff0110204 > > >>> > > 0xfffffffff0105ff0=0x000000002badb002 > > >>> > > 0xfffffffff0105ff8=0x000000000023b000 > > >>> > > cpu0: exiting > > >>> > > > > >>> > > > > > >>> > > > > > >>> > > > On Tue, Jan 28, 2025 at 6:09?AM <tlaro...@kergis.com> wrote: > > >>> > > > > > >>> > > > > After fixing problems leading to compiler > warnings---legitimate > > >>> > > > > warnings, but even the too short binary negated unsigned > 32bits values > > >>> > > > > promoted to 64 bits with leading bits hence 0 as mask were > harmless--- > > >>> > > > > now I want to look at the stumbing block. > > >>> > > > > > > >>> > > > > For me, under vmx, this is the assert in map.c:17: > > >>> > > > > > > >>> > > > > assert(pa < KSEG2); > > >>> > > > > > > >>> > > > > that triggers, and it should come from a call from multiboot. > > >>> > > > > > > >>> > > > > My first reflex is to start adding printf() instructions to > track the > > >>> > > > > problem, but is there a better way when dealing with the > kernel? > > >>> > > > > > > >>> > > > > Second question: since, if I'm not mistaken, 9front doesn't > use > > >>> > > > > multiboot, is vmx usable (i.e. agnostic about) with the > multiboot > > >>> > > stuff? > > >>> > > > > The embedded boot stuff should handle the thing by itself > without load > > >>> > > > > addresses having to be adjusted because of vmx? > > >>> > > > > -- > > >>> > > > > Thierry Laronde <tlaronde +AT+ kergis +dot+ com> > > >>> > > > > http://www.kergis.com/ > > >>> > > > > http://kertex.kergis.com/ > > >>> > > > > Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 > 6006 F40C > > >>> > > > > >>> > > -- > > >>> > > Thierry Laronde <tlaronde +AT+ kergis +dot+ com> > > >>> > > http://www.kergis.com/ > > >>> > > http://kertex.kergis.com/ > > >>> > > Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 > F40C > > >>> > > >>> -- > > >>> Thierry Laronde <tlaronde +AT+ kergis +dot+ com> > > >>> http://www.kergis.com/ > > >>> http://kertex.kergis.com/ > > >>> Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C > > > > > > 9fans / 9fans / see discussions + participants + delivery options > Permalink > > -- > Thierry Laronde <tlaronde +AT+ kergis +dot+ com> > http://www.kergis.com/ > http://kertex.kergis.com/ > Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T8b5b89fcf829819e-Mecbe892c7c26bc685f4e5f37 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
