[PATCH 07/13] RISC-V: KVM: Don't flush TLB in gstage_set_pte() when PTE is unchanged

[Anup Patel]

The gstage_set_pte() should flush remote TLB only when a leaf PTE
changes so that unnecessary remote TLB flushes can be avoided.

Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
 arch/riscv/kvm/mmu.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 1087ea74567b..d4eb1999b794 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -167,9 +167,11 @@ static int gstage_set_pte(struct kvm *kvm, u32 level,
 		ptep = &next_ptep[gstage_pte_index(addr, current_level)];
 	}
 
-	set_pte(ptep, *new_pte);
-	if (gstage_pte_leaf(ptep))
-		gstage_remote_tlb_flush(kvm, current_level, addr);
+	if (pte_val(*ptep) != pte_val(*new_pte)) {
+		set_pte(ptep, *new_pte);
+		if (gstage_pte_leaf(ptep))
+			gstage_remote_tlb_flush(kvm, current_level, addr);
+	}
 
 	return 0;
 }
-- 
2.43.0