Messages in this thread | | | Subject | Re: commit 3c2e7f7de3 (KVM use NPT page attributes) causes boot failures | From | Xiao Guangrong <> | Date | Tue, 1 Sep 2015 21:00:07 +0800 |
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On 09/01/2015 06:04 PM, Markus Trippelsdorf wrote: > On 2015.09.01 at 10:56 +0200, Ingo Molnar wrote: >> >> * Markus Trippelsdorf <markus@trippelsdorf.de> wrote: >>> As I wrote in my other reply. The boot failure is nondeterministic (boot >>> succeeds roughly every sixth time). So the bisection and the patch is >>> just bogus (,but the boot failure is real). >>> >>> Sorry. >> >> No problem. Please let us know if any of these commits does turn out to be the >> culprit. (Which is always a possibility.) > > I'm pretty sure commit 3c2e7f7de3 is the culprit. > > commit 3c2e7f7de3240216042b61073803b61b9b3cfb22 > Author: Paolo Bonzini <pbonzini@redhat.com> > Date: Tue Jul 7 14:32:17 2015 +0200 > > KVM: SVM: use NPT page attributes > > I've booted ten times in a row successfully with the following patch: > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 74d825716f4f..3190173a575f 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -989,7 +989,7 @@ static __init int svm_hardware_setup(void) > } else > kvm_disable_tdp(); > > - build_mtrr2protval(); > +// build_mtrr2protval(); > return 0; > > err: > > Paolo, your commit causes nondeterministic boot failure on my machine. > It sometimes crashes early with the following backtrace: >
Did it trigger the BUG()/BUG_ON() in mtrr2protval()/fallback_mtrr_type()? If yes, could you please print the actual value out?
BTW, you may change BUG() to WARN() to get the print info more easier.
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