On 8/29/22 09:02, Dionna Amalie Glaze wrote: >>> The stack track is in mm/page_alloc.c. I've done a little >>> investigation, but I can't account for why there's a hard cutoff of >>> correctness at 256GB >>> >>> [ 0.065563] RIP: 0010:memmap_init_range+0x108/0x173 >>> [ 0.066309] Code: 77 16 f6 42 10 02 74 10 48 03 42 08 48 c1 e8 0c >>> 48 89 c3 e9 3a ff ff ff 48 89 df 48 c1 e7 06 48 03 3d d9 a2 66 ff 48 >>> 8d 47 08 <c7> 47 34 01 00 00 00 48 c7 47 38 00 00 00 00 c7 47 30 ff ff >>> ff ff >>> [ 0.069108] RSP: 0000:ffffffffad603dc8 EFLAGS: 00010082 ORIG_RAX: >>> 0000000000000404 >>> [ 0.070193] RAX: ffffdba740000048 RBX: 0000000000000001 RCX: 0000000000000000 >>> [ 0.071170] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffdba740000040 >>> [ 0.072224] RBP: 0000000000000000 R08: 0000000000001000 R09: 0000000000000000 >>> [ 0.073283] R10: 0000000000000001 R11: ffffffffad645c60 R12: 0000000000000000 >>> [ 0.074304] R13: 00000000000000a0 R14: 0000000000000000 R15: 0000000000000000 >>> [ 0.075285] FS: 0000000000000000(0000) GS:ffffffffadd6c000(0000) >>> knlGS:0000000000000000 >>> [ 0.076365] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> [ 0.077194] CR2: ffffdba740000074 CR3: 0008001ee3a0c000 CR4: 00000000000606b0 >>> [ 0.078209] Call Trace: >>> [ 0.078524] <TASK> >>> [ 0.078887] ? free_area_init+0x5c1/0x66c >>> [ 0.079417] ? zone_sizes_init+0x52/0x6c >>> [ 0.079934] ? setup_arch+0xa55/0xb6d >>> [ 0.080417] ? start_kernel+0x64/0x65a >>> [ 0.080897] ? secondary_startup_64_no_verify+0xd6/0xdb >>> [ 0.081620] </TASK> >> Note that there is a bug in Brijesh's version of the patch and it will >> almost exclusively use the MSR protocol. Please try the version of the >> patch that I recently sent up based on the current unaccepted memory tree >> from Kirill. >> > I've now tested this patch set with Tom's new patch set, and it > appears to be that the problem with 256GB is more likely to be due to > this unaccepted memory patch set rather than something AMD-specific. > > Kirill, do you see any problems with 256GB on TDX? It seems there is > some unaccepted memory getting touched in memmap_init_range when the > VM's memory size is at least 256GB It really helps this kind of stuff if you can post the *actual* error. I assume this was a page fault, so there should have been some other stuff before the RIP:... Another thing that's really nice is to do the disassembly of the "Code:" or share disassembly of memmap_init_range. Even nicer would be to give an faddr2line of the RIP value and track down which C code was actually at fault. It's *possible* to look into these things from what you posted, but it's just slow. I'm sure Kirill will appreciate the help.
