Commit 870d4d4e authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Replace MMU_DEBUG with proper KVM_PROVE_MMU Kconfig 



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: default avatarPhilippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-10-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 72e2fb24

arch/x86/kvm/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/mmu/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -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++) {

arch/x86/kvm/mmu/mmu_internal.h

+1 −3
Original line number Diff line number Diff line
@@ -6,9 +6,7 @@ 
#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)