# Great BUG in FreeBSD-8.4 as guest with virtio



## Paul-LKW (Sep 14, 2013)

Hi Aall:

Just found that FreeBSD 8.4 as a guest in a Linux KVM with virtio (d_e_spite you are using "vtnet" or "virtio_blk") has a great bug when CARP for supporting a cluster is enabled. It will cause a kernel dump when mounting the file system. It makes the vi_rt_ualization absolute_ly_ useless. Below is the dump.

Remark: If no CARP is enabled in rc.conf, all is working fine at boot time and once the system is up and running it could manually enable CARP and it does not have a problem and works stable.


```
Sep 14 20:15:04 Testing kernel: Fatal trap 12: page fault while in kernel mode
Sep 14 20:15:04 Testing kernel: cpuid = 0; apic id = 00
Sep 14 20:15:04 Testing kernel: fault virtual address   = 0x3070726164
Sep 14 20:15:04 Testing kernel: fault code              = supervisor read data, page not present
Sep 14 20:15:04 Testing kernel: instruction pointer     = 0x20:0xffffffff81215c18
Sep 14 20:15:04 Testing kernel: stack pointer           = 0x28:0xffffff8000196860
Sep 14 20:15:04 Testing kernel: frame pointer           = 0x28:0xffffff8000196930
Sep 14 20:15:04 Testing kernel: code segment            = base 0x0, limit 0xfffff, type 0x1b
Sep 14 20:15:04 Testing kernel: = DPL 0, pres 1, long 1, def32 0, gran 1
Sep 14 20:15:04 Testing kernel: processor eflags        = interrupt enabled, resume, IOPL = 0
Sep 14 20:15:04 Testing kernel: current process         = 314 (ifconfig)
Sep 14 20:15:04 Testing kernel: trap number             = 12
Sep 14 20:15:04 Testing kernel: panic: page fault
Sep 14 20:15:04 Testing kernel: cpuid = 0
Sep 14 20:15:04 Testing kernel: KDB: stack backtrace:
Sep 14 20:15:04 Testing kernel: #0 0xffffffff8066cb66 at kdb_backtrace+0x66
Sep 14 20:15:04 Testing kernel: #1 0xffffffff8063922e at panic+0x1ce
Sep 14 20:15:04 Testing kernel: #2 0xffffffff809c2020 at trap_fatal+0x290
Sep 14 20:15:04 Testing kernel: #3 0xffffffff809c23ae at trap_pfault+0x23e
Sep 14 20:15:04 Testing kernel: #4 0xffffffff809c287e at trap+0x3ce
Sep 14 20:15:04 Testing kernel: #5 0xffffffff809a9474 at calltrap+0x8
Sep 14 20:15:04 Testing kernel: #6 0xffffffff806ea5bd at ifioctl+0x87d
Sep 14 20:15:04 Testing kernel: #7 0xffffffff8067c922 at kern_ioctl+0x102
Sep 14 20:15:04 Testing kernel: #8 0xffffffff8067cb5d at ioctl+0xfd
Sep 14 20:15:04 Testing kernel: #9 0xffffffff809c15f4 at amd64_syscall+0x1f4
Sep 14 20:15:04 Testing kernel: #10 0xffffffff809a976c at Xfast_syscall+0xfc
Sep 14 20:15:04 Testing kernel: Uptime: 6s
Sep 14 20:15:04 Testing kernel: Cannot dump. Device not defined or unavailable.
Sep 14 20:15:04 Testing kernel: Automatic reboot in 15 seconds - press a key on the console to abort
```

*A*ny idea how to fix it?

Thanks in advance.


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