In order to pave the way for more concurrent MMU operations, updates to
VM-global stats need to be done atomically. Change updates to the lpages
stat to be atomic in preparation for the introduction of parallel page
fault handling.
Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1ecd6d51c0ee0..56587655aecb9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1532,7 +1532,7 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep)
WARN_ON(page_header(__pa(sptep))->role.level ==
PT_PAGE_TABLE_LEVEL);
drop_spte(kvm, sptep);
- --kvm->stat.lpages;
+ xadd(&kvm->stat.lpages, -1);
return true;
}
@@ -2676,7 +2676,7 @@ static bool mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
if (is_last_spte(pte, sp->role.level)) {
drop_spte(kvm, spte);
if (is_large_pte(pte))
- --kvm->stat.lpages;
+ xadd(&kvm->stat.lpages, -1);
} else {
child = page_header(pte & PT64_BASE_ADDR_MASK);
drop_parent_pte(child, spte);
@@ -3134,7 +3134,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
pgprintk("%s: setting spte %llx\n", __func__, *sptep);
trace_kvm_mmu_set_spte(level, gfn, sptep);
if (!was_rmapped && is_large_pte(*sptep))
- ++vcpu->kvm->stat.lpages;
+ xadd(&vcpu->kvm->stat.lpages, 1);
if (is_shadow_present_pte(*sptep)) {
if (!was_rmapped) {
--
2.23.0.444.g18eeb5a265-goog
