From 870d4d4ed82779e717ec7fb0f9b64f43bd7a736b Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 28 Jul 2023 17:47:19 -0700 Subject: [PATCH] KVM: x86/mmu: Replace MMU_DEBUG with proper KVM_PROVE_MMU Kconfig MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Link: https://lore.kernel.org/r/20230729004722.1056172-10-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/Kconfig | 13 +++++++++++++ arch/x86/kvm/mmu/mmu.c | 2 +- arch/x86/kvm/mmu/mmu_internal.h | 4 +--- 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 66dbd1f..ed90f14 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -138,6 +138,19 @@ config KVM_XEN 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 diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ab33259..baa3123 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1691,7 +1691,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 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++) { diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 6b6cd30..606f343 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -6,9 +6,7 @@ #include #include -#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) -- 2.7.4