Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Sat, 20 Nov 2021 04:50:41 +0000
In-Reply-To: <20211120045046.3940942-1-seanjc@google.com>
Message-Id: <20211120045046.3940942-24-seanjc@google.com>
Mime-Version: 1.0
References: <20211120045046.3940942-1-seanjc@google.com>
Subject: [PATCH 23/28] KVM: x86/mmu: Use "zap root" path for "slow" zap of all
 TDP MMU SPTEs
From:   Sean Christopherson <seanjc@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Hou Wenlong <houwenlong93@linux.alibaba.com>,
        Ben Gardon <bgardon@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Now that the "slow" zap of all TDP MMU SPTEs doesn't flush the TLBs, use
the dedicated "zap root" helper, which can be used if and only if a flush
isn't needed.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index e5401f0efe8e..99ea19e763da 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -888,6 +888,7 @@ bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start,
 
 void kvm_tdp_mmu_zap_all(struct kvm *kvm)
 {
+	struct kvm_mmu_page *root;
 	int i;
 
 	/*
@@ -895,8 +896,10 @@ void kvm_tdp_mmu_zap_all(struct kvm *kvm)
 	 * is being destroyed or the userspace VMM has exited.  In both cases,
 	 * KVM_RUN is unreachable, i.e. no vCPUs will ever service the request.
 	 */
-	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
-		(void)kvm_tdp_mmu_zap_gfn_range(kvm, i, 0, -1ull, false);
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		for_each_tdp_mmu_root_yield_safe(kvm, root, i, false)
+			(void)tdp_mmu_zap_root(kvm, root, false);
+	}
 }
 
 /*
-- 
2.34.0.rc2.393.gf8c9666880-goog