Re: Illegal instruction errors under XEN3_DOM0 on -CURRENT

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Apr 21, 2020 at 12:49:12AM -0500, Dustin Marquess wrote:
> 
> awk:
> 
> (gdb) where
> #0  0x0000000142a13d14 in syminit ()
> #1  0x0000000000000000 in ?? ()
> (gdb) disas syminit
> Dump of assembler code for function syminit:
>    0x0000000142a13d00 <+0>:       push   %rbp
>    0x0000000142a13d01 <+1>:       push   %rbx
>    0x0000000142a13d02 <+2>:       sub    $0x8,%rsp
>    0x0000000142a13d06 <+6>:       lea    0x21f613(%rip),%rbx        #
> 0x142c33320 <symtab>
>    0x0000000142a13d0d <+13>:      lea    0x180b9(%rip),%rsi        # 0x142a2bdcd
> => 0x0000000142a13d14 <+20>:      vxorpd %xmm0,%xmm0,%xmm0
>    0x0000000142a13d18 <+24>:      mov    %rsi,%rdi
> 
> mount_tmpfs:
> disasm:
>    0x0000775e1fd6fd67 <+1151>:    cmp    $0x10,%r14d
>    0x0000775e1fd6fd6b <+1155>:    cmovle %r14d,%r13d
>    0x0000775e1fd6fd6f <+1159>:    mov    %ebp,%eax
>    0x0000775e1fd6fd71 <+1161>:    cmp    $0x9,%r14d
> => 0x0000775e1fd6fd75 <+1165>:    vcvtsi2sd %rax,%xmm0,%xmm0
>    0x0000775e1fd6fd7a <+1170>:    vmovdqa %xmm0,%xmm1
> 
> 
> ntpd:
> diasm:
>    0x000000019d07b0d1 <+185>:     jne    0x19d07b0e7 <get_systime+207>
>    0x000000019d07b0d3 <+187>:     lea    0x2b8f1e(%rip),%rax        #
> 0x19d333ff8 <sys_lamport>
>    0x000000019d07b0da <+194>:     movl   $0x1,0x2b6120(%rip)        #
> 0x19d331204
>    0x000000019d07b0e4 <+204>:     incq   (%rax)
>    0x000000019d07b0e7 <+207>:     lea    0x2b8f02(%rip),%r12        #
> 0x19d333ff0 <using_sigio>
> => 0x000000019d07b0ee <+214>:     vmovdqa (%rsp),%xmm0
>    0x000000019d07b0f3 <+219>:     mov    (%r12),%r9d
> 
> 

These are all SSE2 or AVX instructions (hard to tell which variant
they are). Maybe Xen is failing to enable something here ?
What does 'cpuctl identify 0' tell in both the native and Xen case ?
Also please post the dmesg from Xen (xl dmesg) and NetBSD.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--