amd64/170388: 8-STABLE amd64 past r233799 is unable to boot in certain KVM environments

[Jimmy Olgeni]

>Number:         170388
>Category:       amd64
>Synopsis:       8-STABLE amd64 past r233799 is unable to boot in certain KVM environments
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Aug 05 09:40:02 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Jimmy Olgeni
>Release:        FreeBSD 8.3-STABLE amd64
>Organization:
>Environment:
>Description:

FreeBSD 8-STABLE is unable to boot in some KVM environments after r233799.

------------------------------------------------------------------------
r233799 | jkim | 2012-04-02 20:27:06 +0200 (Mon, 02 Apr 2012) | 4 lines

MFC:    r233702

Work around Erratum 721 for AMD Family 10h and 12h processors.

------------------------------------------------------------------------

The following panic message is shown immediately after the kernel starts:

===
kernel trap 9 with interrupts disabled

Fatal trap 9: general protection fault while in kernel mode
cpuid = 0; apic id = 00
instruction pointer    = 0x20:0xffffffff808fd8dc
stack pointer          = 0x28:0xffffffff80cd5440
frame pointer          = 0x28:0xffffffff80cd5470
code segment           = base 0x0,  limit 0xfffff, type 0x1b
                       = DPL 0, pres 1,  long 1, def32 0, gran 1
processor eflags       = resume,  IOPL = 0
current process        = 0 ()
trap number            = 9
panic: general protection fault
cpuid = 0
KDB: stack backtrace:
#0 0xffffffff8064e18e at ??+0
#1 0xffffffff8061b247 at ??+0
#2 0xffffffff80912ca0 at ??+0
#3 0xffffffff80913235 at ??+0
#4 0xffffffff808faad4 at ??+0
#5 0xffffffff80904cc2 at ??+0
#6 0xffffffff801a0244 at ??+0
===

When booting from the latest 8-STABLE branch the booting process
just halts after the first panic line.

The same problem can be observed in 9-STABLE, but I did not actually
bisect all the way to the relevant commit yet. However, r233702
seems a reasonable guess.

Once the system is booted by reverting r233799, the following
processor information can be read:

    CPU: Six-Core AMD Opteron(tm) Processor 2427 (2211.49-MHz K8-class CPU)
      Origin = "AuthenticAMD"  Id = 0x100f80  Family = 10  Model = 8  Stepping = 0
      Features=0x783fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE,SSE2>
      Features2=0x80802001<SSE3,CX16,POPCNT,HV>
      AMD Features=0xe6500800<SYSCALL,NX,MMX+,FFXSR,Page1GB,LM,3DNow!+,3DNow!>
      AMD Features2=0x1f7<LAHF,CMP,SVM,CR8,ABM,SSE4A,MAS,Prefetch>
      TSC: P-state invariant

Also, using x86info:

    x86info v1.30.  Dave Jones 2001-2011
    Feedback to <davej at redhat.com>.

    Extended Family: 1 Extended Model: 0 Family: 15 Model: 8 Stepping: 0
    CPU Model (x86info's best guess): Phenom/Athlon/Sempron/Turion (II)/Opteron (HY-D0)
    Processor name string (BIOS programmed): Six-Core AMD Opteron(tm) Processor 2427

    Monitor/Mwait: min/max line size 0/0, ecx bit 0 support, enumeration extension
    SVM: revision 1, 16 ASIDs, np, NRIPSave
    Address Size: 48 bits virtual, 40 bits physical
    running at an estimated 2.35GHz

Unfortunately I have no detailed information about the QEMU
configuration, but I set up a dedicated VM that I could use to test
patches.

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