Re: QEMU PCIe expander bridge with 64kB page guest -> guest BUG_ON()

[Eric Auger]

Adding Yubo in the loop as Jiahui's address is bouncing.


On 6/21/21 6:22 PM, Eric Auger wrote:
> Hi Jiahui,
> 
> I noticed the PCIe expander bridge + PCIe root port does not work with a
> 64kB page guest. One hits a kernel BUG at mm/vmalloc.c:96
> (BUG_ON(!pte_none(*pte));)! This happens with an upstream guest.
> 
> I understand this happens on pci_remap_iospace when handling the Io16
> regions below. Wonder if the edk2 code could be the source (I saw you
> write both the edk2 and the qemu part [edk2-devel] [PATCH v2 0/4] Add
> extra pci roots support for Arm).
> 
> Please could give me a hand?
> 
> Best Regards
> 
> Eric
> 
> 
> Sample qemu cmd options:
> 
> -device pxb-pcie,bus_nr=4,id=bridge,bus=pcie.0 \
> -device pcie-root-port,bus=bridge,chassis=4,id=pcie.11 \
> -device virtio-net-pci,bus=pcie.11,netdev=nic0,mac=6a:f5:10:b1:3d:d2
> -netdev
> tap,id=nic0,script=/home/augere/TEST/SCRIPTS/qemu-ifup,downscript=/home/augere/TEST/SCRIPTS/qemu-ifdown
> 
> 
> [    2.867734] ACPI: PCI Root Bridge [PCFE] (domain 0000 [bus fe-ff])
> [    2.869339] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM
> ClockPM Segments MSI EDR HPX-Type3]
> [    2.871405] acpi PNP0A08:00: _OSC: platform does not support [LTR DPC]
> [    2.873226] acpi PNP0A08:00: _OSC: OS now controls [PCIeHotplug PME
> AER PCIeCapability]
> [    2.875609] acpi PNP0A08:00: ECAM area [mem
> 0x401fe00000-0x401fffffff] reserved by PNP0C02:00
> [    2.877830] acpi PNP0A08:00: ECAM at [mem 0x401fe00000-0x401fffffff]
> for [bus fe-ff]
> phys_addr=0x3eff3000
> [    2.884036] ------------[ cut here ]------------
> [    2.885249] kernel BUG at mm/vmalloc.c:96!
> [    2.886322] Internal error: Oops - BUG: 0 [#1] SMP
> [    2.887560] Modules linked in:
> [    2.888352] CPU: 7 PID: 1 Comm: swapper/0 Not tainted
> 5.13.0-rc6-guest-64K+ #57
> [    2.890216] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0
> 02/06/2015
> [    2.891983] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
> [    2.893519] pc : vmap_range+0x1d8/0x208
> [    2.894600] lr : vmap_range+0x38/0x208
> [    2.895615] sp : fffffe0012c2f7f0
> [    2.896517] x29: fffffe0012c2f7f0 x28: fffffffefe800000 x27:
> fffffffefe801000
> [    2.898437] x26: ffffffff20070000 x25: 00000001407f0000 x24:
> 0140000000000000
> [    2.900357] x23: fffffe001134ffb8 x22: 000000000000003f x21:
> 0068000000000717
> [    2.902284] x20: 000000003eff3000 x19: fffffffefe801000 x18:
> 0000000000000010
> [    2.904236] x17: 0000000000000000 x16: 0000000000000001 x15:
> ffffffffffffffff
> [    2.906157] x14: 695f70616d65725f x13: 696370202a2a2a2a x12:
> fffffe0011c77150
> [    2.908084] x11: 0000000000000003 x10: fffffe0011bb7110 x9 :
> fffffe0010d33ad4
> [    2.909996] x8 : 00000000000bffe8 x7 : c0000000ffff7fff x6 :
> 0000000000000001
> [    2.911323] x5 : 0000000000000000 x4 : 000000003eff0000 x3 :
> 0000000000001ff7
> [    2.912631] x2 : 0040000000000001 x1 : fffffc07f4080038 x0 :
> fffffc07ffbecdc0
> [    2.913951] Call trace:
> [    2.914398]  vmap_range+0x1d8/0x208
> [    2.915363]  ioremap_page_range+0x20/0x30
> [    2.916453]  pci_remap_iospace+0xcc/0xf0
> [    2.917519]  acpi_pci_probe_root_resources+0x244/0x268
> [    2.918907]  pci_acpi_root_prepare_resources+0x28/0xc8
> [    2.920281]  acpi_pci_root_create+0x9c/0x2f8
> [    2.921443]  pci_acpi_scan_root+0x14c/0x230
> [    2.922574]  acpi_pci_root_add+0x268/0x5c0
> [    2.923710]  acpi_bus_attach+0x15c/0x2c0
> [    2.924794]  acpi_bus_attach+0x9c/0x2c0
> [    2.925833]  acpi_bus_attach+0x9c/0x2c0
> [    2.926881]  acpi_bus_scan+0x64/0x118
> [    2.927875]  acpi_scan_init+0x10c/0x25c
> [    2.928922]  acpi_init+0x3e8/0x458
> [    2.929847]  do_one_initcall+0x54/0x268
> [    2.930879]  kernel_init_freeable+0x290/0x344
> [    2.932068]  kernel_init+0x1c/0x128
> [    2.933017]  ret_from_fork+0x10/0x18
> [    2.934005] Code: a90687e2 97f518e5 a94687e2 17ffffe4 (d4210000)
> [    2.935673] ---[ end trace 1d687ce361e3e7ca ]---
> [    2.936922] Kernel panic - not syncing: Oops - BUG: Fatal exception
> [    2.938611] SMP: stopping secondary CPUs
> [    2.939760] ---[ end Kernel panic - not syncing: Oops - BUG: Fatal
> exception ]---
> 
> 
> At EDK2 level I have:
> 
> PciBus: Resource Map for Root Bridge PciRoot(0x0)^M
> Type =   Io16; Base = 0x0;      Length = 0x3000;        Alignment = 0xFFF^M
>    Base = 0x0;  Length = 0x200; Alignment = 0xFFF;      Owner = PPB
> [00|02|02:**]^M
>    Base = 0x1000;       Length = 0x200; Alignment = 0xFFF;      Owner =
> PPB [00|02|01:**]^M
>    Base = 0x2000;       Length = 0x200; Alignment = 0xFFF;      Owner =
> PPB [00|02|00:**]^M
> Type =  Mem32; Base = 0x10000000;       Length = 0x700000;
> Alignment = 0x1FFFFF^M
>    Base = 0x10000000;   Length = 0x200000;      Alignment = 0x1FFFFF;
> Owner = PPB [00|02|02:**]^M
>    Base = 0x10200000;   Length = 0x200000;      Alignment = 0x1FFFFF;
> Owner = PPB [00|02|01:**]^M
>    Base = 0x10400000;   Length = 0x200000;      Alignment = 0x1FFFFF;
> Owner = PPB [00|02|00:**]^M
>    Base = 0x10600000;   Length = 0x1000;        Alignment = 0xFFF;
> Owner = PPB [00|02|02:10]^M
>    Base = 0x10601000;   Length = 0x1000;        Alignment = 0xFFF;
> Owner = PPB [00|02|01:10]^M
>    Base = 0x10602000;   Length = 0x1000;        Alignment = 0xFFF;
> Owner = PPB [00|02|00:10]^M
> Type =  Mem64; Base = 0x8000000000;     Length = 0x200000;
> Alignment = 0xFFFFF^M
>    Base = 0x8000000000; Length = 0x100000;      Alignment = 0xFFFFF;
> Owner = PPB [00|02|01:**]; Type = PMem64^M
>    Base = 0x8000100000; Length = 0x100000;      Alignment = 0xFFFFF;
> Owner = PPB [00|02|02:**]; Type = PMem64^M
> 
> 
> PciBus: Resource Map for Root Bridge PciRoot(0x4)^M
> Type =   Io16; Base = 0x3000;   Length = 0x1000;        Alignment = 0xFFF^M
>    Base = 0x3000;       Length = 0x200; Alignment = 0xFFF;      Owner =
> PPB [04|00|00:**]^M
> Type =  Mem32; Base = 0x10800000;       Length = 0x300000;
> Alignment = 0x1FFFFF^M
>    Base = 0x10800000;   Length = 0x200000;      Alignment = 0x1FFFFF;
> Owner = PPB [04|00|00:**]^M
>    Base = 0x10A00000;   Length = 0x1000;        Alignment = 0xFFF;
> Owner = PPB [04|00|00:10]^M
> ^M
> PciBus: Resource Map for Bridge [04|00|00]^M
> Type =   Io16; Base = 0x3000;   Length = 0x200; Alignment = 0xFFF^M
>    Base = Padding;      Length = 0x200; Alignment = 0x1FF^M
> Type =  Mem32; Base = 0x10800000;       Length = 0x200000;
> Alignment = 0x1FFFFF^M
>    Base = Padding;      Length = 0x200000;      Alignment = 0x1FFFFF^M
> Type =  Mem32; Base = 0x10A00000;       Length = 0x1000;
> Alignment = 0xFFF^M
>