> From: Nadav Har'El [mailto:nyh@xxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, May 25, 2011 1:38 PM > > On Wed, May 25, 2011, Tian, Kevin wrote about "RE: [PATCH 21/31] nVMX: > vmcs12 checks on nested entry": > > > + if (vmcs12->launch_state == launch) { > > > + nested_vmx_failValid(vcpu, > > > + launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS > > > + : VMXERR_VMRESUME_NONLAUNCHED_VMCS); > > > + return 1; > > > + } > > > > from SDM: > > ELSIF (VMLAUNCH and launch state of current VMCS is not "clear") > > THEN VMfailValid(VMLAUNCH with non-clear VMCS); > > ELSIF (VMRESUME and launch state of current VMCS is not "launched") > > THEN VMfailValid(VMRESUME with non-launched VMCS); > > > > So it's legal to use VMLAUNCH on a launched VMCS. However here you > > changes this behavior. On the other hand, do you want to add a 'clear' state > > along with L1 VMCLEAR to catch the failure here? > > I don't understand: I always understood the spec to mean that "clear" and > "launched" the two opposite states of the "launch state" bit? If it isn't, > what does "clear" mean? > > Is it really "legal to use a VMLAUNCH on a launched VMCS"? > If it is, why does KVM, for example, go to great lengths to VMLAUNCH the > first time, and VMRESUME all subsequent times? > You're correct. I've got my head messed on this point. :-) Thanks Kevin -- 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
