/me reminds you of 78 char text wrap. On Wed, Jul 09, 2014 at 07:32:09PM +0000, Liang, Kan wrote: > > Sure; but what I meant was, check_msr() is broken when ran on such a > > kernel. You need to fix check_msr() to return failure on these 'ignored' > > MSRs, after all they don't function as expected, they're effectively broken. > > The function is designed to check if the MSRs can be safely accessed > (no #GP). It cannot guarantee the correctness of the MSRs. If KVM > applied patch 2 and guest applied patch 1, from the guest's > perspective, the MSRs can be accessed (no #GP triggered). So return > true is expected. It should not be a broken. You're not understanding. I know you wrote that function to do that. I'm saying that's wrong. Look at check_hw_exists() it explicitly checks for fake MSRs and reports them broken. These fake MSRs _ARE_ broken, they do not behave as expected. Not crashing is not the right consideration here, we're interested in higher order correct behaviour. > The only unexpected > thing for guest is that the counting/sampling result for LBR/extra reg > is always 0. But the patch is a short term fix to stop things from > crashing. I think it should be acceptable. Patch 2 is fine, patch 1, in particular your check_msr() routine is not. -- 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
