On 11/02/21 22:22, Bandan Das wrote:
The pcid-disabled test from kvm-unit-tests fails on a Milan host because the processor injects a #GP while the test expects #UD. While setting the intercept when the guest has it disabled seemed like the obvious thing to do, Babu Moger (AMD) pointed me to an earlier discussion here - https://lkml.org/lkml/2020/6/11/949 Jim points out there that #GP has precedence over the intercept bit when invpcid is called with CPL > 0 and so even if we intercept invpcid, the guest would end up with getting and "incorrect" exception. To inject the right exception, I created an entry for the instruction in the emulator to decode it successfully and then inject a UD instead of a GP when the guest has it disabled. Bandan Das (3): KVM: Add a stub for invpcid in the emulator table KVM: SVM: Handle invpcid during gp interception KVM: SVM: check if we need to track GP intercept for invpcid arch/x86/kvm/emulate.c | 3 ++- arch/x86/kvm/svm/svm.c | 22 +++++++++++++++++++++- 2 files changed, 23 insertions(+), 2 deletions(-)
Isn't this the same thing that "[PATCH 1/3] KVM: SVM: Intercept INVPCID when it's disabled to inject #UD" also does?
Paolo
