On Tue, Aug 22, 2023, Tom Lendacky wrote: > On 8/10/23 18:49, Sean Christopherson wrote: > > Fix a bug where KVM injects a bogus #UD for SEV guests when trying to skip > > an INT3 as part of re-injecting the associated #BP that got kinda sorta > > intercepted due to a #NPF occuring while vectoring/delivering the #BP. > > > > I haven't actually confirmed that patch 1 fixes the bug, as it's a > > different change than what I originally proposed. I'm 99% certain it will > > work, but I definitely need verification that it fixes the problem > > > > Patch 2 is a tangentially related cleanup to make NRIPS a requirement for > > enabling SEV, e.g. so that we don't ever get "bug" reports of SEV guests > > not working when NRIPS is disabled. > > > > Sean Christopherson (2): > > KVM: SVM: Don't inject #UD if KVM attempts emulation of SEV guest w/o > > insn > > KVM: SVM: Require nrips support for SEV guests (and beyond) > > > > arch/x86/kvm/svm/sev.c | 2 +- > > arch/x86/kvm/svm/svm.c | 37 ++++++++++++++++++++----------------- > > arch/x86/kvm/svm/svm.h | 1 + > > 3 files changed, 22 insertions(+), 18 deletions(-) > > We ran some stress tests against a version of the kernel without this fix > and we're able to reproduce the issue, but not reliably, after a few hours. > With this patch, it has not reproduced after running for a week. > > Not as reliable a scenario as the original reporter, but this looks like it > resolves the issue. Thanks Tom! I'll apply this for v6.6, that'll give us plenty of time to change course if necessary.
