Re: [PATCH 2/3] target/riscv: add helper_tlb_flush_page()

[Daniel Henrique Barboza]

On 8/31/2026 3:59 PM, Trevor Gamblin wrote:

Add a page-level counterpart to helper_tlb_flush(), and condition its
internal call to tlb_flush_page() on return value from the new
sfence_vma_allowed() function.

Signed-off-by: Trevor Gamblin <tgamb...@baylibre.com>
---

I believe this code should be squashed into patch 3 where there's an
actual caller for helper_tlb_flush_page.

Also ...

  target/riscv/helper.h        | 1 +
  target/riscv/tcg/op_helper.c | 7 +++++++
  2 files changed, 8 insertions(+)

diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index 4fc2d3a155..652f85a5c7 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -137,6 +137,7 @@ DEF_HELPER_1(ctr_clear, void, env)
  DEF_HELPER_1(wfi, void, env)
  DEF_HELPER_1(wrs_nto, void, env)
  DEF_HELPER_1(tlb_flush, void, env)
+DEF_HELPER_2(tlb_flush_page, void, env, tl)
  DEF_HELPER_1(tlb_flush_all, void, env)
  DEF_HELPER_4(ctr_add_entry, void, env, tl, tl, tl)
  /* Native Debug */
diff --git a/target/riscv/tcg/op_helper.c b/target/riscv/tcg/op_helper.c
index 8039df2b48..723a45d181 100644
--- a/target/riscv/tcg/op_helper.c
+++ b/target/riscv/tcg/op_helper.c
@@ -610,6 +610,13 @@ void helper_tlb_flush(CPURISCVState *env)
      }
  }

+void helper_tlb_flush_page(CPURISCVState *env, target_ulong addr)

+{
+    if (sfence_vma_allowed(env, GETPC())) {
+        tlb_flush_page(env_cpu(env), addr);
+    }
+}
+

Following my suggestion in patch 1 this would turn into something like:


void helper_tlb_flush_page(CPURISCVState *env, target_ulong addr)
{
    check_sfence_vma(env, GETPC());
    tlb_flush_page(env_cpu(env), addr);
}


Thanks,
Daniel

  void helper_tlb_flush_all(CPURISCVState *env)
  {
      CPUState *cs = env_cpu(env);