[PATCH 9/9] KVM: x86: Disable KVM_INTEL_PROVE_VE by default

From: Sean Christopherson
Date: Fri May 17 2024 - 20:07:16 EST


Disable KVM's "prove #VE" support by default, as it provides no functional
value, and even its sanity checking benefits are relatively limited. I.e.
it should be fully opt-in even on debug kernels, especially since EPT
Violation #VE suppression appears to be buggy on some CPUs.

Opportunistically add a line in the help text to make it abundantly clear
that KVM_INTEL_PROVE_VE should never be enabled in a production
environment.

Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/Kconfig | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 2a7f69abcac3..3468efc4be55 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -97,15 +97,15 @@ config KVM_INTEL

config KVM_INTEL_PROVE_VE
bool "Check that guests do not receive #VE exceptions"
- default KVM_PROVE_MMU || DEBUG_KERNEL
- depends on KVM_INTEL
+ depends on KVM_INTEL && DEBUG_KERNEL && EXPERT
help
-
Checks that KVM's page table management code will not incorrectly
let guests receive a virtualization exception. Virtualization
exceptions will be trapped by the hypervisor rather than injected
in the guest.

+ This should never be enabled in a production environment.
+
If unsure, say N.

config X86_SGX_KVM
--
2.45.0.215.g3402c0e53f-goog