On Mon, Aug 02, 2010 at 10:24:43AM -0400, Avi Kivity wrote: > On 08/02/2010 05:11 PM, Roedel, Joerg wrote: > > This is testing the failure case without the nested-svm efer patch I > > submitted last week. The sequence above (which switches from long mode > > to real mode and back to long mode) fails without this patch. > > A direct test would be to > > mov $MSR_EFER, %ecx > rdmsr > xor $EFER_NX, %eax > wrmsr > > and see that L1 EFER was updated. > > I don't object to the more complicated test, but in general prefer > simpler, direct tests so that when they fail we know exactly why. True, smaller tests are generally better. But I think its good to also test that the whole sequence works. I can add a seperate test for the efer bug if you want. It gets more tricky to test cr0 or cr4 writes because this will require to put the nested guest into real-mode or protected-mode directly. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632 -- 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
