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authorSean Christopherson <seanjc@google.com>2023-07-29 03:47:19 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2023-08-31 20:48:47 +0300
commit870d4d4ed82779e717ec7fb0f9b64f43bd7a736b (patch)
treeb71764a7e830f8b4ca6b8199046b41c466b210cf /arch/x86
parent72e2fb24a0b0528bcc16a8f6ad2cf336ac361525 (diff)
downloadlinux-870d4d4ed82779e717ec7fb0f9b64f43bd7a736b.tar.xz
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: 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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/Kconfig13
-rw-r--r--arch/x86/kvm/mmu/mmu.c2
-rw-r--r--arch/x86/kvm/mmu/mmu_internal.h4
3 files changed, 15 insertions, 4 deletions
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 66dbd1f4d57d..ed90f148140d 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 ab3325981f9a..baa312388721 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 6b6cd30bcf4b..606f343d99c1 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -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)