Replace MMU_DEBUG, which requires manually modifying KVM to enable the
macro, with a proper Kconfig, KVM_PROVE_MMU. Now that pgprintk() and
rmap_printk() are gone, i.e. the macro guards only KVM_MMU_WARN_ON() and
won't flood the kernel logs, enabling the option for debug kernels is both
desirable and feasible.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If in doubt, say "N".
+config KVM_PROVE_MMU
+ bool "Prove KVM MMU correctness"
+ depends on DEBUG_KERNEL
+ depends on KVM
+ depends on EXPERT
+ help
+ Enables runtime assertions in KVM's MMU that are too costly to enable
+ in anything remotely resembling a production environment, e.g. this
+ gates code that verifies a to-be-freed page table doesn't have any
+ present SPTEs.
+
+ If in doubt, say "N".
+
config KVM_EXTERNAL_WRITE_TRACKING
bool
static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp)
{
-#ifdef MMU_DEBUG
+#ifdef CONFIG_KVM_PROVE_MMU
int i;
for (i = 0; i < SPTE_ENT_PER_PAGE; i++) {
#include <linux/kvm_host.h>
#include <asm/kvm_host.h>
-#undef MMU_DEBUG
-
-#ifdef MMU_DEBUG
+#ifdef CONFIG_KVM_PROVE_MMU
#define KVM_MMU_WARN_ON(x) WARN_ON_ONCE(x)
#else
#define KVM_MMU_WARN_ON(x) do { } while (0)