On Thu, Sep 19, 2013 at 08:49:51PM +0300, Andriy Gapon wrote: > on 19/09/2013 19:53 Paolo Bonzini said the following: > > Il 19/09/2013 16:36, Andriy Gapon ha scritto: > >> Not sure how the code ends up at 0x9315 after that. > > > > Events are dropped, probably corresponding to more emulation. > > I've got a trace without dropped events between the last "normal" instruction > and the loop (and also including a snippet where the same code is executed > without a problem): Which kernel version is this? What BSD version?
> ... > qemu-system-x86-12024 [003] 278157.048876: kvm_emulate_insn: 0:9366:b1 10 > (prot32) > qemu-system-x86-12024 [003] 278157.048877: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.048878: kvm_emulate_insn: 0:9368:8e d1 > (prot32) > qemu-system-x86-12024 [003] 278157.048880: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.048882: kvm_exit: reason > CR_ACCESS rip 0x9312 info 0 0 > qemu-system-x86-12024 [003] 278157.048883: kvm_cr: cr_write 0 > = 0x10 > qemu-system-x86-12024 [003] 278157.048885: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.048886: kvm_emulate_insn: 0:9315:ea 1a > 93 00 00 (real) > qemu-system-x86-12024 [003] 278157.048887: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.048888: kvm_emulate_insn: 0:931a:31 c0 > (real) > ... ... > qemu-system-x86-12024 [003] 278157.048990: kvm_set_irq: gsi 4 level > 0 > source 0 > qemu-system-x86-12024 [003] 278157.048991: kvm_pic_set_irq: chip 0 pin 4 > (edge|masked) > qemu-system-x86-12024 [003] 278157.048992: kvm_ioapic_set_irq: pin 4 dst 0 > vec=0 (Fixed|physical|edge|masked) > qemu-system-x86-12024 [003] 278157.049001: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.049002: kvm_exit: reason > IO_INSTRUCTION rip 0x1e675 info 3fd0008 0 > qemu-system-x86-12024 [003] 278157.049005: kvm_emulate_insn: > a000:1e675:ec > (prot32) > qemu-system-x86-12024 [003] 278157.049005: kvm_pio: pio_read at > 0x3fd size 1 count 1 > qemu-system-x86-12024 [003] 278157.049006: kvm_userspace_exit: reason > KVM_EXIT_IO (2) > qemu-system-x86-12024 [003] 278157.049024: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.049027: kvm_exit: reason > CR_ACCESS rip 0x9312 info 0 0 > qemu-system-x86-12024 [003] 278157.049028: kvm_cr: cr_write 0 > = 0x10 > qemu-system-x86-12024 [003] 278157.049030: kvm_entry: vcpu 0 > qemu-system-x86-12024 [003] 278157.049031: kvm_emulate_insn: 0:9315: > (real) > qemu-system-x86-12024 [003] 278157.049033: kvm_emulate_insn: 0:9315: > (real) > qemu-system-x86-12024 [003] 278157.049034: kvm_emulate_insn: 0:9315: > (real) > ... > > It's strange that no instruction gets reported in those repeating "0:9315: > (real)" lines. It's like kvm is somehow losing track of what should be > executed > and just loops over the same ip without actually doing anything. > > -- > Andriy Gapon -- Gleb.