Quoting Avi Kivity (avi@xxxxxxxxxx): > On 04/09/2011 12:09 AM, Serge E. Hallyn wrote: > >Hi, > > > >at https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/747090, it was > >found that emulate_int_real() sometimes pushes the wrong eip when doing a > >int. Whereas with non-kvm qemu we push the next instruction after the > >int, with kvm we push the addr of the instruction itself. > > > > > The code says: > > c->src.val = c->eip; > emulate_push(ctxt, ops); > rc = writeback(ctxt, ops); > if (rc != X86EMUL_CONTINUE) > return rc; > > which appears to be the address of the next instruction from my > reading of the code (see how insn_fetch() increments c->eip). Nevertheless removing commits a92601bb707f6f49fd5563ef3d09928e70cc222e 63995653ade16deacaea5b49ceaf6376314593ac 6e154e56b4d7a6a28c54f0984e13d3f8defc4755 changes the eip value being pushed. If you look at a92601bb707f6f49fd5563ef3d09928e70cc222e, you see: if (vmx->rmode.vm86_active) { - vmx->rmode.irq.pending = true; - vmx->rmode.irq.vector = nr; - vmx->rmode.irq.rip = kvm_rip_read(vcpu); - if (kvm_exception_is_soft(nr)) - vmx->rmode.irq.rip += - vmx->vcpu.arch.event_exit_inst_len; - intr_info |= INTR_TYPE_SOFT_INTR; - vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info); - vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, 1); - kvm_rip_write(vcpu, vmx->rmode.irq.rip - 1); + if (kvm_inject_realmode_interrupt(vcpu, nr) != EMULATE_DONE) + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); return; } but kvm_inject_realmode_interrupt() does not appear to increment vmx->rmode.irq.rip anywhere, as the code being replaced does. -serge -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
