Date:   Mon,  6 Feb 2023 17:23:38 +0000
In-Reply-To: <20230206172340.2639971-1-rananta@google.com>
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References: <20230206172340.2639971-1-rananta@google.com>
Message-ID: <20230206172340.2639971-6-rananta@google.com>
Subject: [PATCH v2 5/7] KVM: arm64: Flush only the memslot after write-protect
From:   Raghavendra Rao Ananta <rananta@google.com>
To:     Oliver Upton <oupton@google.com>, Marc Zyngier <maz@kernel.org>,
        Ricardo Koller <ricarkol@google.com>,
        Reiji Watanabe <reijiw@google.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Will Deacon <will@kernel.org>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jing Zhang <jingzhangos@google.com>,
        Colton Lewis <coltonlewis@google.com>,
        Raghavendra Rao Anata <rananta@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

After write-protecting the region, currently KVM invalidates
the entire TLB entries using kvm_flush_remote_tlbs(). Instead,
scope the invalidation only to the targeted memslot. If
supported, the architecture would use the range-based TLBI
instructions to flush the memslot or else fallback to flushing
all of the TLBs.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
---
 arch/arm64/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 409cb187f4911..3e33af0daf1d3 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -981,7 +981,7 @@ static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
 	write_lock(&kvm->mmu_lock);
 	stage2_wp_range(&kvm->arch.mmu, start, end);
 	write_unlock(&kvm->mmu_lock);
-	kvm_flush_remote_tlbs(kvm);
+	kvm_flush_remote_tlbs_memslot(kvm, memslot);
 }
 
 /**
-- 
2.39.1.519.gcb327c4b5f-goog