Xen project Mailing List

Hi Xen developers,

We are hitting a DomU Linux kernel panic and we’d like to find a solution for it.

We are porting our virtual appliance to Amazon’s AWS. Our kernel is 2.6.27.57. We know it is old but we have to stay with it for now. The problem is when the kernel (64-bit) boots up in EC2 ( a large instance with 7.5 GB memory), the kernel crashes when hitting the BUG in enlighten.c:pin_pagetable_pfn():

static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)

{

struct mmuext_op op;

op.cmd = cmd;

op.arg1.mfn = pfn_to_mfn(pfn);

if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))

BUG();

}

The complete kernel log is attached below. We noticed we don’t see this panic with 2.6.32 kernel. But we’d like to keep with the 2.6.27 kernel if possible. Does anyone know if there’s a patch that can fix this problem?

Here are some additional information about this panic:

1. In pin_pagetable_pfn, before it hits BUG, the pfn is 0x180011 and the mfn is 0x6c7b1.

2. It doesn’t crash when the total memory is less than 4GB.

Does anything know the cause and if there’s any solution to it?

Thanks,

Joe

[ 0.000000] Linux version 2.6.27 (root@dev64-build1) (gcc version 4.1.1) #3 SMP Sun Jun 9 05:11:27 IST 2013

[ 0.000000] Command line: root=/dev/ram0 rw load_ramdisk=1 ramdisk_size=350000 console=tty0,9600n8 console=ttyS0,9600n8 bfile=disk_pri

[ 0.000000] KERNEL supported cpus:

[ 0.000000] Intel GenuineIntel

[ 0.000000] AMD AuthenticAMD

[ 0.000000] Centaur CentaurHauls

[ 0.000000] ACPI in unprivileged domain disabled

[ 0.000000] BIOS-provided physical RAM map:

[ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable)

[ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)

[ 0.000000] Xen: 0000000000100000 - 0000000008cc2000 (usable)

[ 0.000000] Xen: 0000000008cc2000 - 0000000009bc5000 (reserved)

[ 0.000000] Xen: 0000000009bc5000 - 00000001e0000000 (usable)

[ 0.000000] last_pfn = 0x1e0000 max_arch_pfn = 0x3ffffffff

[ 0.000000] last_pfn = 0x100000 max_arch_pfn = 0x3ffffffff

[ 0.000000] init_memory_mapping

[ 0.000000] last_map_addr: 100000000 end: 100000000

[ 0.000000] init_memory_mapping

[ 0.000000] last_map_addr: 1e0000000 end: 1e0000000

[ 0.000000] RAMDISK: 009b9000 - 08cc2000

[ 0.000000] DMI not present or invalid.

[ 0.000000] No NUMA configuration found

[ 0.000000] Faking a node at 0000000000000000-00000001e0000000

[ 0.000000] Bootmem setup node 0 0000000000000000-00000001e0000000

[ 0.000000] NODE_DATA [0000000000001000 - 0000000000005fff]

[ 0.000000] bootmap [0000000000008000 - 0000000000043fff] pages 3c

[ 0.000000] (7 early reservations) ==> bootmem [0000000000 - 01e0000000]

[ 0.000000] #0 [0000000000 - 0000001000] BIOS data page ==> [0000000000 - 0000001000]

[ 0.000000] #1 [0000006000 - 0000008000] TRAMPOLINE ==> [0000006000 - 0000008000]

[ 0.000000] #2 [0009bc5000 - 0009c18000] XEN PAGETABLES ==> [0009bc5000 - 0009c18000]

[ 0.000000] #3 [0000200000 - 00009b8568] TEXT DATA BSS ==> [0000200000 - 00009b8568]

[ 0.000000] #4 [00009b9000 - 0008cc2000] RAMDISK ==> [00009b9000 - 0008cc2000]

[ 0.000000] #5 [0009c18000 - 000a3c7000] PGTABLE ==> [0009c18000 - 000a3c7000]

[ 0.000000] #6 [000a3c7000 - 000aacb000] PGTABLE ==> [000a3c7000 - 000aacb000]

[ 0.000000] Zone PFN ranges:

[ 0.000000] DMA 0x00000000 -> 0x00001000

[ 0.000000] DMA32 0x00001000 -> 0x00100000

[ 0.000000] Normal 0x00100000 -> 0x001e0000

[ 0.000000] Movable zone start PFN for each node

[ 0.000000] early_node_map[3] active PFN ranges

[ 0.000000] 0: 0x00000000 -> 0x000000a0

[ 0.000000] 0: 0x00000100 -> 0x00008cc2

[ 0.000000] 0: 0x00009bc5 -> 0x001e0000

[ 0.000000] SMP: Allowing 2 CPUs, 0 hotplug CPUs

[ 0.000000] No local APIC present

[ 0.000000] PCI: Warning: Cannot find a gap in the 32bit address range

[ 0.000000] PCI: Unassigned devices with 32bit resource registers may break!

[ 0.000000] Allocating PCI resources starting at 1e0200000 (gap: 1e0100000:400000)

[ 0.000000] PERCPU: Allocating 59040 bytes of per cpu data

[ 0.000000] Built 1 zonelists in Node order, mobility grouping on. Total pages: 1933282

[ 0.000000] Policy zone: Normal

[ 0.000000] Kernel command line: root=/dev/ram0 rw load_ramdisk=1 ramdisk_size=350000 console=tty0,9600n8 console=ttyS0,9600n8 bfile=disk_pri

[ 0.000000] Initializing CPU#0

[ 0.000000] PID hash table entries: 4096 (order: 12, 32768 bytes)

[ 0.000000] Detected 1999.975 MHz processor.

[ 0.004000] Console: colour dummy device 80x25

[ 0.004000] console [tty0] enabled

[ 0.004000] console [hvc0] enabled

[ 0.004000] console [ttyS0] enabled