Re: kvm: KVM internal error. Suberror: 1

[Avi Kivity]

On 05/06/2012 08:19 PM, Sasha Levin wrote:
> Hi all,
>
> During some fuzzing with trinity in a KVM guest running on qemu, I got the following error:
>
> KVM internal error. Suberror: 1
> emulation failure
> RAX=0000000000000000 RBX=ffff8800284108e0 RCX=0000000000000001 RDX=ffffffff84482008
> RSI=1030000000000000 RDI=8180000000000000 RBP=ffff880028723d38 RSP=ffff880028723ce8
> R8 =0000000000000206 R9 =fffffffff7e80206 R10=0000000000000000 R11=0000000000000000
> R12=ffff880028410000 R13=ffffffff846ba1c0 R14=ffffffff84a74970 R15=0000000000009530
> RIP=ffffffff8111c862 RFL=00010046 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =0000 0000000000000000 ffffffff 00000000
> CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
> SS =0018 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
> DS =0000 0000000000000000 ffffffff 00000000
> FS =0000 00007f955873b700 ffffffff 00000000
> GS =0000 ffff880035a00000 ffffffff 00000000
> LDT=0000 0000000000000000 ffffffff 00000000
> TR =0040 ffff880035bd2480 00002087 00008b00 DPL=0 TSS64-busy
> GDT=     ffff880035a04000 0000007f
> IDT=     ffffffff8436a000 00000fff
> CR0=8005003b CR2=00007f5cfdad0518 CR3=000000001a154000 CR4=000407e0
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 
> DR6=00000000ffff0ff0 DR7=0000000000000400
> EFER=0000000000000d01
> Code=66 90 e8 7b 97 ff ff b8 01 00 00 00 eb 1c 0f 1f 40 00 31 c0 <83> 3d 97 9f c7 02 00 0f 95 c0 eb 0a 66 90 31 c0 66 0f 1f 44 00 00 48 8b 5d d8 4c 8b 65 e0
> KVM internal error. Suberror: 1
> emulation failure

This is cmpl   $0x0,0x2c79f97(%rip) # 0xffffffff83d96800.  I don't
understand why it failed, we do emulate cmp.  I'll try to write a unit
test for it.


> RAX=ffff88000d5f8000 RBX=ffff88000d600010 RCX=0000000000000001 RDX=0000000000000000
> RSI=0000000000000001 RDI=ffff88000d5f8000 RBP=ffff88000d601ec8 RSP=ffff88000d601ec8
> R8 =0000000000000001 R9 =0000000000000000 R10=0000000000000000 R11=0000000000000000
> R12=ffffffff83fed960 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000
> RIP=ffffffff8107d696 RFL=00000286 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =0000 0000000000000000 ffffffff 00000000
> CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
> SS =0018 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
> DS =0000 0000000000000000 ffffffff 00000000
> FS =0000 0000000000000000 ffffffff 00000000
> GS =0000 ffff880029800000 ffffffff 00000000
> LDT=0000 0000000000000000 ffffffff 00000000
> TR =0040 ffff8800299d2480 00002087 00008b00 DPL=0 TSS64-busy
> GDT=     ffff880029804000 0000007f
> IDT=     ffffffff8436a000 00000fff
> CR0=8005003b CR2=00007fcfa03f9e9c CR3=0000000003a1c000 CR4=000407e0
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 
> DR6=00000000ffff0ff0 DR7=0000000000000400
> EFER=0000000000000d01
> Code=89 e5 fb c9 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <c9> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 c9 c3 66 0f 1f 84 00 00 00 00 00 55 8b 07 48
> KVM internal error. Suberror: 1
> emulation failure
> RAX=ffff88000d5db000 RBX=ffff88000d5ce010 RCX=0000000000000001 RDX=0000000000000000
> RSI=0000000000000001 RDI=ffff88000d5db000 RBP=ffff88000d5cfec8 RSP=ffff88000d5cfec8
> R8 =0000000000000001 R9 =0000000000000000 R10=0000000000000000 R11=0000000000000000
> R12=ffffffff83fed960 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000
> RIP=ffffffff8107d696 RFL=00000286 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =0000 0000000000000000 ffffffff 00000000
> CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
> SS =0018 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
> DS =0000 0000000000000000 ffffffff 00000000
> FS =0000 0000000000000000 ffffffff 00000000
> GS =0000 ffff88001b800000 ffffffff 00000000
> LDT=0000 0000000000000000 ffffffff 00000000
> TR =0040 ffff88001b9d2480 00002087 00008b00 DPL=0 TSS64-busy
> GDT=     ffff88001b804000 0000007f
> IDT=     ffffffff8436a000 00000fff
> CR0=8005003b CR2=00007fcfa076b518 CR3=000000001a148000 CR4=000407e0
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 
> DR6=00000000ffff0ff0 DR7=0000000000000400
> EFER=0000000000000d01
> Code=89 e5 fb c9 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <c9> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 c9 c3 66 0f 1f 84 00 00 00 00 00 55 8b 07 48
>
> The assembly doesn't quite make sense, and the fact that I got 3 of these in a row, makes me believe that it isn't an actual emulation error, but something else.
>

The assembly makes sense, it's sti; hlt; leaveq. What doesn't make sense
is that we have to emulate leaveq - rsp and rbp point at normal memory
as far as I can tell.

The fact that it often happens after hlt makes me suspect interrupts are
involved.  Please run this again with a trace so we so what happens
prior to the error.

-- 
error compiling committee.c: too many arguments to function

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