[PATCH v3 4/6] KVM: x86/mmu: Reduce gfn range of tlb flushing in tdp_mmu_map_handle_target_level()

From: Hou Wenlong
Date: Fri Sep 23 2022 - 06:53:05 EST


Since the children SP is zapped, the gfn range of tlb flushing should be
the range covered by children SP not parent SP. Replace sp->gfn which is
the base gfn of parent SP with iter->gfn and use the correct size of
gfn range for children SP to reduce tlb flushing range.

Fixes: bb95dfb9e2df ("KVM: x86/mmu: Defer TLB flush to caller when freeing TDP MMU shadow pages")
Signed-off-by: Hou Wenlong <houwenlong.hwl@xxxxxxxxxxxx>
Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
---
arch/x86/kvm/mmu/tdp_mmu.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index bf2ccf9debca..2d223c5167f8 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1071,8 +1071,7 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
return RET_PF_RETRY;
else if (is_shadow_present_pte(iter->old_spte) &&
!is_last_spte(iter->old_spte, iter->level))
- kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn,
- KVM_PAGES_PER_HPAGE(iter->level + 1));
+ kvm_flush_remote_tlbs_gfn(vcpu->kvm, iter->gfn, iter->level);

/*
* If the page fault was caused by a write but the page is write
--
2.31.1