Re: [Qemu-devel] VM can not boot after commit 235e898

[Alexander Graf]

On 07/24/2013 05:21 PM, Gleb Natapov wrote:
> On Wed, Jul 24, 2013 at 05:16:09PM +0200, Paolo Bonzini wrote:
> > Il 24/07/2013 11:58, Alexander Graf ha scritto:
> > > > > No QEMU or kvm crashes, no error message printed, I mean it just hangs, even no 
> > > > > BIOS information are printed.
> > > > > And "top" shows QEMU consumes 100% cpu.
> > > > >
> > > > > When I define DEBUG_KVM in kvm-all.c, and run QEMU(this time I boot a normal OS 
> > > > > disk),
> > > > > # x86_64-softmmu/qemu-system-x86_64 -enable-kvm -hda 
> > > > > /mnt/nfs/Images/debian-append.img
> > > > > kvm_init_vcpu
> > > > > kvm_cpu_exec()
> > > > > handle_io
> > > > > handle_io
> > > > > handle_io
> > > > > handle_io
> > > > >
> > > > > Only 4 debug messages(handle_io) are printed, then nothing is shown, and "top" 
> > > > > shows QEMU process uses 100% CPU.
> > > After this we're running in an endless loop of:
> > >
> > >   qemu-system-x86-9298  [003] ...1 162090.918845: kvm_emulate_insn: 
> > > f0000:c489:66 ea 91 c4 0f 00 08 00 (prot16)
> > >   qemu-system-x86-9298  [003] d..2 162090.918846: kvm_entry: vcpu 0
> > >
> > >    (qemu) x /i $pc
> > >    0x00000000000fc489:  ljmpl  $0x8,$0xfc491
> > >
> > > With current master, qemu-system-x86_64 -enable-kvm is broken on at least 3.7 
> > > kernels (openSUSE 12.3).
> > >
> > > Gleb, I don't remember all the glorious details of ljmpl, but would it have to 
> > > raise an MMIO request for a read-only memory slot which it fails to do?
> > The point of KVM_CAP_READONLY_MEM should be that it doesn't.
> Yes, it should not. Can you provide complete trace of kvm and kvmmmu
> event up until failure?

Sure! These are all trace events up to the loop that I was able to fetch 
from the "kvm" and "kvmmmu" event bucket in /sys/kernel/debug/tracing.


 qemu-system-x86-13149 [001] ...1 185370.437938: kvm_set_irq: gsi 8 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437942: kvm_pic_set_irq: chip 
1 pin 0 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437943: kvm_ioapic_set_irq: 
pin 8 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.437945: kvm_set_irq: gsi 4 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437946: kvm_pic_set_irq: chip 
0 pin 4 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437946: kvm_ioapic_set_irq: 
pin 4 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.437947: kvm_set_irq: gsi 1 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437947: kvm_pic_set_irq: chip 
0 pin 1 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437948: kvm_ioapic_set_irq: 
pin 1 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.437948: kvm_set_irq: gsi 12 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437948: kvm_pic_set_irq: chip 
1 pin 4 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437949: kvm_ioapic_set_irq: 
pin 12 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.437949: kvm_set_irq: gsi 1 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437949: kvm_pic_set_irq: chip 
0 pin 1 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437949: kvm_ioapic_set_irq: 
pin 1 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.437950: kvm_set_irq: gsi 12 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.437950: kvm_pic_set_irq: chip 
1 pin 4 (edge)
 qemu-system-x86-13149 [001] ...2 185370.437950: kvm_ioapic_set_irq: 
pin 12 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.438050: kvm_set_irq: gsi 0 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.438051: kvm_pic_set_irq: chip 
0 pin 0 (edge)
 qemu-system-x86-13149 [001] ...2 185370.438051: kvm_ioapic_set_irq: 
pin 2 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.438052: kvm_set_irq: gsi 0 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.438052: kvm_pic_set_irq: chip 
0 pin 0 (edge)
 qemu-system-x86-13149 [001] ...2 185370.438052: kvm_ioapic_set_irq: 
pin 2 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13149 [001] ...1 185370.438052: kvm_set_irq: gsi 0 
level 0 source 0
 qemu-system-x86-13149 [001] ...2 185370.438053: kvm_pic_set_irq: chip 
0 pin 0 (edge)
 qemu-system-x86-13149 [001] ...2 185370.438053: kvm_ioapic_set_irq: 
pin 2 dst 0 vec=0 (Fixed|physical|edge|masked)
 qemu-system-x86-13150 [000] ...2 185370.441730: kvm_mmu_get_page: sp 
gfn 0 4 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] ...2 185370.441734: kvm_fpu: load
 qemu-system-x86-13150 [000] d..2 185370.441734: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441738: kvm_exit: reason 
EPT_VIOLATION rip 0xfff0 info 81 0
 qemu-system-x86-13150 [000] ...1 185370.441739: kvm_page_fault: 
address feffc000 error_code 81
 qemu-system-x86-13150 [000] ...2 185370.441746: kvm_mmu_get_page: sp 
gfn 0 3 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] ...2 185370.441748: kvm_mmu_get_page: sp 
gfn c0000 2 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] ...2 185370.441749: kvm_mmu_get_page: sp 
gfn fee00 1 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] d..2 185370.441752: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441757: kvm_exit: reason 
EPT_VIOLATION rip 0xfff0 info 184 0
 qemu-system-x86-13150 [000] ...1 185370.441757: kvm_page_fault: 
address ffff0 error_code 184
 qemu-system-x86-13150 [000] ...2 185370.441760: kvm_mmu_get_page: sp 
gfn 0 2 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] ...2 185370.441761: kvm_mmu_get_page: sp 
gfn 0 1 q0 direct wux !nxe root 0 sync new
 qemu-system-x86-13150 [000] d..2 185370.441762: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441763: kvm_exit: reason 
EPT_VIOLATION rip 0xe05b info 184 0
 qemu-system-x86-13150 [000] ...1 185370.441763: kvm_page_fault: 
address fe05b error_code 184
 qemu-system-x86-13150 [000] d..2 185370.441764: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441765: kvm_exit: reason 
EPT_VIOLATION rip 0xe05b info 181 0
 qemu-system-x86-13150 [000] ...1 185370.441765: kvm_page_fault: 
address fd094 error_code 181
 qemu-system-x86-13150 [000] d..2 185370.441766: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441767: kvm_exit: reason 
EPT_VIOLATION rip 0xc45e info 184 0
 qemu-system-x86-13150 [000] ...1 185370.441767: kvm_page_fault: 
address fc45e error_code 184
 qemu-system-x86-13150 [000] d..2 185370.441768: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441769: kvm_exit: reason 
EPT_VIOLATION rip 0xc469 info 181 0
 qemu-system-x86-13150 [000] ...1 185370.441769: kvm_page_fault: 
address feffd066 error_code 181
 qemu-system-x86-13150 [000] d..2 185370.441771: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441772: kvm_exit: reason 
IO_INSTRUCTION rip 0xc469 info 700040 0
 qemu-system-x86-13150 [000] ...1 185370.441773: kvm_pio: pio_write at 
0x70 size 1 count 1
 qemu-system-x86-13150 [000] ...1 185370.441775: kvm_userspace_exit: 
reason KVM_EXIT_IO (2)
 qemu-system-x86-13150 [000] ...2 185370.441776: kvm_fpu: unload
 qemu-system-x86-13150 [000] d..2 185370.441787: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441788: kvm_exit: reason 
IO_INSTRUCTION rip 0xc46b info 710048 0
 qemu-system-x86-13150 [000] ...1 185370.441794: kvm_emulate_insn: 
f0000:c46b:e4 71 (real)
 qemu-system-x86-13150 [000] ...1 185370.441796: kvm_pio: pio_read at 
0x71 size 1 count 1
 qemu-system-x86-13150 [000] ...1 185370.441797: kvm_userspace_exit: 
reason KVM_EXIT_IO (2)
 qemu-system-x86-13150 [000] d..2 185370.441804: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441805: kvm_exit: reason 
IO_INSTRUCTION rip 0xc46d info 920048 0
 qemu-system-x86-13150 [000] ...1 185370.441806: kvm_emulate_insn: 
f0000:c46d:e4 92 (real)
 qemu-system-x86-13150 [000] ...1 185370.441807: kvm_pio: pio_read at 
0x92 size 1 count 1
 qemu-system-x86-13150 [000] ...1 185370.441807: kvm_userspace_exit: 
reason KVM_EXIT_IO (2)
 qemu-system-x86-13150 [000] d..2 185370.441810: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441811: kvm_exit: reason 
IO_INSTRUCTION rip 0xc471 info 920040 0
 qemu-system-x86-13150 [000] ...1 185370.441811: kvm_pio: pio_write at 
0x92 size 1 count 1
 qemu-system-x86-13150 [000] ...1 185370.441811: kvm_userspace_exit: 
reason KVM_EXIT_IO (2)
 qemu-system-x86-13150 [000] d..2 185370.441813: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441814: kvm_exit: reason 
EXCEPTION_NMI rip 0xc473 info 0 80000b0d
 qemu-system-x86-13150 [000] ...1 185370.441817: kvm_emulate_insn: 
f0000:c473:2e 0f 01 1e e0 d3 (real)
 qemu-system-x86-13150 [000] d..2 185370.441819: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441820: kvm_exit: reason 
EXCEPTION_NMI rip 0xc479 info 0 80000b0d
 qemu-system-x86-13150 [000] ...1 185370.441821: kvm_emulate_insn: 
f0000:c479:2e 0f 01 16 a0 d3 (real)
 qemu-system-x86-13150 [000] d..2 185370.441822: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441823: kvm_exit: reason 
EXCEPTION_NMI rip 0xc47f info 0 80000b0d
 qemu-system-x86-13150 [000] ...1 185370.441824: kvm_emulate_insn: 
f0000:c47f:0f 20 c0 (real)
 qemu-system-x86-13150 [000] d..2 185370.441825: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] d..2 185370.441826: kvm_exit: reason 
EXCEPTION_NMI rip 0xc486 info 0 80000b0d
 qemu-system-x86-13150 [000] ...1 185370.441826: kvm_emulate_insn: 
f0000:c486:0f 22 c0 (real)
 qemu-system-x86-13150 [000] d..2 185370.441829: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] ...1 185370.441830: kvm_emulate_insn: 
f0000:c489:66 ea 91 c4 0f 00 08 00 (prot16)
 qemu-system-x86-13150 [000] d..2 185370.441833: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] ...1 185370.441833: kvm_emulate_insn: 
f0000:c489:66 ea 91 c4 0f 00 08 00 (prot16)
 qemu-system-x86-13150 [000] d..2 185370.441834: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] ...1 185370.441835: kvm_emulate_insn: 
f0000:c489:66 ea 91 c4 0f 00 08 00 (prot16)
 qemu-system-x86-13150 [000] d..2 185370.441835: kvm_entry: vcpu 0
 qemu-system-x86-13150 [000] ...1 185370.441836: kvm_emulate_insn: 
f0000:c489:66 ea 91 c4 0f 00 08 00 (prot16)
 qemu-system-x86-13150 [000] d..2 185370.441836: kvm_entry: vcpu 0
[...]


Alex