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 Permalink: https://9fans.topicbox.com/groups/9fans/T8b5b89fcf829819e-M4e4ecc487efb27f806e7cd5c Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
