On Fri, Apr 23, 2010 at 04:42:52PM +0200, Alexander Graf wrote: > > On 23.04.2010, at 16:31, Joerg Roedel wrote: > > > On Fri, Apr 23, 2010 at 04:24:54PM +0200, Alexander Graf wrote: > >> > >> On 23.04.2010, at 16:22, Joerg Roedel wrote: > > > >>> No, nested_svm_nmi runs in atomic context where we can't emulate a > >>> vmexit. We set exit_required and emulate the vmexit later. > >> > >> So we modify the L2 rflags and then trigger a #vmexit, leaving the l2 > >> state broken? > > > > No, the rflags are changed in enable_nmi_window which isn't called when > > we run nested and the nested hypervisor intercepts nmi. So it only runs > > in the !nested case where it can't corrupt L2 state. > > Last time I checked the code enable_nmi_window was the function > triggering the #vmexit, Yes, thats the bug which this patch fixes :-) >so it should run in that exact scenario. If what you say is true, where >do we #vmexit instead then? After setting exit_required we run into svm.c:svm_vcpu_run. There the exit_required flag is checked and if set, the function immediatly returns without doing a vmrun. A few cycles later we run into svm.c:handle_exit() where at the beginning exit_required is checked, and if set the vmexit is emulated. Joerg -- 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
