linux-kernel - [PATCH 08/24] KVM: x86/mmu: Drop redundant trace_kvm_mmu_set

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Message-Id: <20210225204749.1512652-9-seanjc@google.com>
Date:   Thu, 25 Feb 2021 12:47:33 -0800
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Ben Gardon <bgardon@...gle.com>
Subject: [PATCH 08/24] KVM: x86/mmu: Drop redundant trace_kvm_mmu_set_spte()
 in the TDP MMU

Remove TDP MMU's call to trace_kvm_mmu_set_spte() that is done for both
shadow-present SPTEs and MMIO SPTEs.  It's fully redundant for the
former, and unnecessary for the latter.  This aligns TDP MMU tracing
behavior with that of the legacy MMU.

Fixes: 33dd3574f5fe ("kvm: x86/mmu: Add existing trace points to TDP MMU")
Cc: Ben Gardon <bgardon@...gle.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index f46972892a2d..782cae1eb5e1 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -773,12 +773,11 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, int write,
 		trace_mark_mmio_spte(rcu_dereference(iter->sptep), iter->gfn,
 				     new_spte);
 		ret = RET_PF_EMULATE;
-	} else
+	} else {
 		trace_kvm_mmu_set_spte(iter->level, iter->gfn,
 				       rcu_dereference(iter->sptep));
+	}
 
-	trace_kvm_mmu_set_spte(iter->level, iter->gfn,
-			       rcu_dereference(iter->sptep));
 	if (!prefault)
 		vcpu->stat.pf_fixed++;
 
-- 
2.30.1.766.gb4fecdf3b7-goog