linux-kernel - [PATCH 1/3] KVM: x86/mmu: Drop a redundant, broken remote TLB flush

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Message-Id: <20211022010005.1454978-2-seanjc@google.com>
Date:   Thu, 21 Oct 2021 18:00:03 -0700
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, Maxim Levitsky <mlevitsk@...hat.com>,
        "Maciej S . Szmigiero" <maciej.szmigiero@...cle.com>,
        Ben Gardon <bgardon@...gle.com>
Subject: [PATCH 1/3] KVM: x86/mmu: Drop a redundant, broken remote TLB flush

A recent commit to fix the calls to kvm_flush_remote_tlbs_with_address()
in kvm_zap_gfn_range() inadvertantly added yet another flush instead of
fixing the existing flush.  Drop the redundant flush, and fix the params
for the existing flush.

Fixes: 2822da446640 ("KVM: x86/mmu: fix parameters to kvm_flush_remote_tlbs_with_address")
Cc: Maxim Levitsky <mlevitsk@...hat.com>
Cc: Maciej S. Szmigiero <maciej.szmigiero@...cle.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/mmu.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c6ddb042b281..f82b192bba0b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5709,13 +5709,11 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 		for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 			flush = kvm_tdp_mmu_zap_gfn_range(kvm, i, gfn_start,
 							  gfn_end, flush);
-		if (flush)
-			kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
-							   gfn_end - gfn_start);
 	}
 
 	if (flush)
-		kvm_flush_remote_tlbs_with_address(kvm, gfn_start, gfn_end);
+		kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
+						   gfn_end - gfn_start);
 
 	kvm_dec_notifier_count(kvm, gfn_start, gfn_end);
 
-- 
2.33.0.1079.g6e70778dc9-goog