On Mon, Jul 30, 2012, siddhesh phadke wrote about "Tracking nested guest ioctl in L0 hypervisor": > I am trying to understand KVM code for nested virtualization and my > goal is to find whether an ioctl performed by L2 guest can be > intercepted in L0. > > Hence just for experimental purpose I wrote an blank ioctl in L2 > guest. When that ioctl is received by L1 KVM hypervisor ,it uses > kvm_hypercall0() mentioned in kvm_para.h to notify L0. Am I doing this > correct or is there any other method to do the same or I am completely > off the track? > > Can anyone please help me with this? Do you really mean an *ioctl* in L2 - which is just a system call in L2 (and never intercepted by L0 or L1), or a *hypercall*? From the mention of kvm_hypercall0() it sounds like you mean a hypercall. As you can see in vmx.c, nested_vmx_exit_handled(), when L0 receives a VMCALL exit (i.e., a hypercall) from L2, we return 1 - meaning that we exit to L1 so that it can handle this hypercall. I believe that this is this is the more sensible behavior, but if you want L0 to handle hypercalls, you can, in the EXIT_REASON_VMCALL case in that function, return 0, which would cause L0 to handle this exit. -- Nadav Har'El | Wednesday, Aug 1 2012, 13 Av 5772 nyh@xxxxxxxxxxxxxxxxxxx |----------------------------------------- Phone +972-523-790466, ICQ 13349191 |Despite the cost of living, have you http://nadav.harel.org.il |noticed how it remains so popular? -- 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
