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From:   "Hou Wenlong" <houwenlong.hwl@antgroup.com>
To:     kvm@vger.kernel.org
Cc:     David Matlack <dmatlack@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org
Subject: [PATCH v2 3/6] KVM: x86/mmu: Reduce gfn range of tlb flushing in tdp_mmu_map_handle_target_level()
Date:   Wed, 24 Aug 2022 17:29:20 +0800
Message-Id: <85f889ce6eb6b330d86fa74c6e84d22d98ddc2cf.1661331396.git.houwenlong.hwl@antgroup.com>
In-Reply-To: <cover.1661331396.git.houwenlong.hwl@antgroup.com>
References: <cover.1661331396.git.houwenlong.hwl@antgroup.com>
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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.

Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index bf2ccf9debca..08b7932122ec 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1071,8 +1071,8 @@ 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_with_address(vcpu->kvm, iter->gfn,
+						   KVM_PAGES_PER_HPAGE(iter->level));
 
 	/*
 	 * If the page fault was caused by a write but the page is write
-- 
2.31.1