diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-06-15 09:29:05 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-06-17 13:10:18 -0400 |
| commit | ade74e1433f32e3fb422e3700d5bab34c57f4f47 (patch) | |
| tree | fb2e7e65696e9caf750343dff169838bba53a0f4 | |
| parent | bca66dbcd28a41c669921ff7ca066f71e6f3e72e (diff) | |
KVM: x86/mmu: Grab nx_lpage_splits as an unsigned long before division
Snapshot kvm->stats.nx_lpage_splits into a local unsigned long to avoid
64-bit division on 32-bit kernels. Casting to an unsigned long is safe
because the maximum number of shadow pages, n_max_mmu_pages, is also an
unsigned long, i.e. KVM will start recycling shadow pages before the
number of splits can exceed a 32-bit value.
ERROR: modpost: "__udivdi3" [arch/x86/kvm/kvm.ko] undefined!
Fixes: 7ee093d4f3f5 ("KVM: switch per-VM stats to u64")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210615162905.2132937-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 720ceb0a1f5c..7d3e57678d34 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6043,6 +6043,7 @@ static int set_nx_huge_pages_recovery_ratio(const char *val, const struct kernel static void kvm_recover_nx_lpages(struct kvm *kvm) { + unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; int rcu_idx; struct kvm_mmu_page *sp; unsigned int ratio; @@ -6054,7 +6055,7 @@ static void kvm_recover_nx_lpages(struct kvm *kvm) write_lock(&kvm->mmu_lock); ratio = READ_ONCE(nx_huge_pages_recovery_ratio); - to_zap = ratio ? DIV_ROUND_UP(kvm->stat.nx_lpage_splits, ratio) : 0; + to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; for ( ; to_zap; --to_zap) { if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) break; |