[Resend PATCH V5 8/10] KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()

From: lantianyu1986
Date: Thu Dec 06 2018 - 08:22:32 EST


From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>

This patch is to move tlb flush in kvm_set_pte_rmapp() to
kvm_mmu_notifier_change_pte() in order to avoid redundant tlb flush.

Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 8 ++------
virt/kvm/kvm_main.c | 5 ++++-
2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dfef49f1e7a6..3b0f60e88f54 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1776,10 +1776,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
}
}

- if (need_flush)
- kvm_flush_remote_tlbs(kvm);
-
- return 0;
+ return need_flush;
}

struct slot_rmap_walk_iterator {
@@ -1915,8 +1912,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)

int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
- kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
- return 0;
+ return kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
}

static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2679e476b6c3..dac4b0446aed 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -354,7 +354,10 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
kvm->mmu_notifier_seq++;
- kvm_set_spte_hva(kvm, address, pte);
+
+ if (kvm_set_spte_hva(kvm, address, pte))
+ kvm_flush_remote_tlbs(kvm);
+
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
}
--
2.14.4