KVM internal error. Suberror: 1, emulation failure
I'm causing qemu to spew these emulation failure messages until I kill it. The guest kernel being run has been hacked up pretty heavily and is probably either accessing bad physical addresses (above the address ranges in the e820 table) or trying to DMA to bad addresses.
What I'd really like qemu to be doing is trapping back in to the guest kernel to have it handle this issue. Then I'd have a better chance of dumping out some debugging information to see where I went wrong.
host kernel: 3.10
guest kernel: Linus commit d2b4a64 + patches
qemu: v1.4.0-2835-g6453a3a
Quoted 44 lines
KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000
TR =0040ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00 KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000
TR =0040ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00
Quoted 5 lines · Dave Hansen
I'm causing qemu to spew these emulation failure messages until I kill it. The guest kernel being run has been hacked up pretty heavily and is probably either accessing bad physical addresses (above the address ranges in the e820 table) or trying to DMA to bad addresses.
It tries to do MMIO from userspace using "pcmpeqb 0x30(%rdi),%xmm1" instruction which KVM does not emulate.
Quoted 4 lines
What I'd really like qemu to be doing is trapping back in to the guest kernel to have it handle this issue. Then I'd have a better chance of dumping out some debugging information to see where I went wrong.
It traps back to the guest and injects #UD otherwise you wouldn't see it spewing this message again and again. If emulation failure happens from guest kernel space then QEMU stops on the first one.
Quoted 48 lines
host kernel: 3.10
guest kernel: Linus commit d2b4a64 + patches
qemu: v1.4.0-2835-g6453a3aQuoted 36 lines
KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000
TR =0040ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00 KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000Quoted 8 lines
TR =0040
ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00
Quoted 4 lines
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Gleb.
Paolo Bonzini
maintainerIl 17/07/2013 18:16, Dave Hansen ha scritto:
Quoted 8 lines
I'm causing qemu to spew these emulation failure messages until I kill it. The guest kernel being run has been hacked up pretty heavily and is probably either accessing bad physical addresses (above the address ranges in the e820 table) or trying to DMA to bad addresses.
What I'd really like qemu to be doing is trapping back in to the guest kernel to have it handle this issue. Then I'd have a better chance of dumping out some debugging information to see where I went wrong.
This is happening because the kernel is executing a PCMPEQB instruction on an invalid memory address. This instruction is not yet emulated by KVM. If you want QEMU to trap back to the guest kernel, you can add emulation of the instruction to arch/x86/kvm/emulate.c.
If you do not really care about the guest doing something sane, you can use a stub emulation function that is just "return emulate_ud(ctxt)". That alone could be a good starting point to attach a kernel debugger to the guest.
Paolo
Quoted 48 lines
host kernel: 3.10
guest kernel: Linus commit d2b4a64 + patches
qemu: v1.4.0-2835-g6453a3aQuoted 44 lines
Quoted 44 lines
KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000
TR =0040ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00 KVM internal error. Suberror: 1
emulation failure
RAX=0000000000000000 RBX=00000000013c0410 RCX=0000000000000010 RDX=0000000000000010
RSI=000000000000000a RDI=00007f6d256a73c0 RBP=ffffffffffffffff RSP=00007fffe2720ce8
R8 =00000000ffffffff R9 =0000000000000000 R10=0000000000000022 R11=0000000000000246
R12=00007fffe2720d58 R13=0000000000000400 R14=00007f6d256a7000 R15=0000000000000000
RIP=00007f6d24c5a50e RFL=00010202 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff00c00000
CS =0033 0000000000000000 ffffffff00a0fb00DPL=3 CS64 [-RA]
SS =002b 0000000000000000 ffffffff00c0f300DPL=3 DS [-WA]
DS =0000 0000000000000000 ffffffff00c00000
FS =000000007f6d2569d740ffffffff00c00000
GS =0000 0000000000000000 ffffffff00c00000
LDT=0000 0000000000000000 ffffffff00c00000
TR =0040ffff88007b1904800000208700008b00DPL=0 TSS64-busy
GDT=ffff88007b1840000000007f
IDT=ffffffffff57a00000000fff
CR0=80050033 CR2=00007f6d256a7000 CR3=000000006f13b000 CR4=000006e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000d01
Code=d7 c3 85 c0 0f 85 bc 00 00 00 48 83 ea 10 0f 8e d2 00 00 00 <66> 0f 74 4f 30 66 0f d7 c1 85 c0 0f 85 b1 00 00 00 48 31 c0 c3 66 66 66 66 2e 0f 1f 84 00
Quoted 15 lines · Paolo Bonzini
Il 17/07/2013 18:16, Dave Hansen ha scritto:
Quoted 8 lines
I'm causing qemu to spew these emulation failure messages until I kill it. The guest kernel being run has been hacked up pretty heavily and is probably either accessing bad physical addresses (above the address ranges in the e820 table) or trying to DMA to bad addresses.
What I'd really like qemu to be doing is trapping back in to the guest kernel to have it handle this issue. Then I'd have a better chance of dumping out some debugging information to see where I went wrong.
This is happening because the kernel is executing a PCMPEQB instruction on an invalid memory address. This instruction is not yet emulated by KVM. If you want QEMU to trap back to the guest kernel, you can add emulation of the instruction to
arch/x86/kvm/emulate.c.
Quoted 5 lines
If you do not really care about the guest doing something sane, you can use a stub emulation function that is just "return
emulate_ud(ctxt)". That alone could be a good starting point to attach a kernel debugger to the guest.
This is the behaviour that he currently gets (assuming there is no bug somewhere, run ftrace to check), see my other reply. Not sure what he does in his #UD handler that emulation error reappear. Restart offending process?
--
Gleb.