KVM: nVMX: Explicitly check for valid guest state for !unrestricted guest
Call guest_state_valid() directly instead of querying emulation_required
when checking if L1 is attempting VM-Enter with invalid guest state.
If emulate_invalid_guest_state is false, KVM will fixup segment regs to
avoid emulation and will never set emulation_required, i.e. KVM will
incorrectly miss the associated consistency checks because the nested
path stuffs segments directly into vmcs02.
Opportunsitically add Consistency Check tracing to make future debug
suck a little less.
Fixes: 2bb8cafea80bf ("KVM: vVMX: signal failure for nested VMEntry if emulation_required")
Fixes: 3184a995f782c ("KVM: nVMX: fix vmentry failure code when L2 state would require emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923184452.980-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 321a679..e004ab8 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2576,7 +2576,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
* which means L1 attempted VMEntry to L2 with invalid state.
* Fail the VMEntry.
*/
- if (vmx->emulation_required) {
+ if (CC(!vmx_guest_state_valid(vcpu))) {
*entry_failure_code = ENTRY_FAIL_DEFAULT;
return -EINVAL;
}