Re: [PATCH 06/23] accel/tcg: Early exit for zero length in tlb_flush_range_by_mmuidx*

[Pierrick Bouvier]

On 10/9/24 08:08, Richard Henderson wrote:
Probably never happens, but next patches will assume non-zero length.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
  accel/tcg/cputlb.c | 6 ++++++
  1 file changed, 6 insertions(+)

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index fd8da8586f..93b42d18ee 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -801,6 +801,9 @@ void tlb_flush_range_by_mmuidx(CPUState *cpu, vaddr addr,
       * If all bits are significant, and len is small,
       * this devolves to tlb_flush_page.
       */
+    if (len == 0) {
+        return;
+    }
      if (bits >= TARGET_LONG_BITS && len <= TARGET_PAGE_SIZE) {
          tlb_flush_page_by_mmuidx(cpu, addr, idxmap);
          return;
@@ -839,6 +842,9 @@ void tlb_flush_range_by_mmuidx_all_cpus_synced(CPUState 
*src_cpu,
       * If all bits are significant, and len is small,
       * this devolves to tlb_flush_page.
       */
+    if (len == 0) {
+        return;
+    }
      if (bits >= TARGET_LONG_BITS && len <= TARGET_PAGE_SIZE) {
          tlb_flush_page_by_mmuidx_all_cpus_synced(src_cpu, addr, idxmap);
          return;

If this "probably never happens", wouldn't that be better to assert that 
len is strictly positive?