linux-kernel - [PATCH v3 6/7] KVM: arm64: Add 'skip_flush' arg to stage2_put

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Date:   Fri, 14 Apr 2023 17:29:21 +0000
From:   Raghavendra Rao Ananta <rananta@...gle.com>
To:     Oliver Upton <oliver.upton@...ux.dev>,
        Marc Zyngier <maz@...nel.org>,
        James Morse <james.morse@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>
Cc:     Ricardo Koller <ricarkol@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Jing Zhang <jingzhangos@...gle.com>,
        Colton Lewis <coltonlewis@...gle.com>,
        Raghavendra Rao Anata <rananta@...gle.com>,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: [PATCH v3 6/7] KVM: arm64: Add 'skip_flush' arg to stage2_put_pte()

Add a 'skip_flush' argument in stage2_put_pte() to
control the TLB invalidations. This will be leveraged
by the upcoming patch to defer the individual PTE
invalidations until the entire walk is finished.

No functional change intended.

Signed-off-by: Raghavendra Rao Ananta <rananta@...gle.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index b8f0dbd12f773..3f136e35feb5e 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -772,7 +772,7 @@ static void stage2_make_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t n
 }
 
 static void stage2_put_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu,
-			   struct kvm_pgtable_mm_ops *mm_ops)
+			   struct kvm_pgtable_mm_ops *mm_ops, bool skip_flush)
 {
 	/*
 	 * Clear the existing PTE, and perform break-before-make with
@@ -780,7 +780,10 @@ static void stage2_put_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s
 	 */
 	if (kvm_pte_valid(ctx->old)) {
 		kvm_clear_pte(ctx->ptep);
-		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);
+
+		if (!skip_flush)
+			kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu,
+					ctx->addr, ctx->level);
 	}
 
 	mm_ops->put_page(ctx->ptep);
@@ -1015,7 +1018,7 @@ static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
 	 * block entry and rely on the remaining portions being faulted
 	 * back lazily.
 	 */
-	stage2_put_pte(ctx, mmu, mm_ops);
+	stage2_put_pte(ctx, mmu, mm_ops, false);
 
 	if (need_flush && mm_ops->dcache_clean_inval_poc)
 		mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops),
-- 
2.40.0.634.g4ca3ef3211-goog