Re: [PATCH v2 RESEND] tcg/loongarch: strip flag bits in lddir/ldpte address calculation

[Bibo Mao]

On 2026/9/20 上午10:42, SignKirigami wrote:
helper_lddir and helper_ldpte used TARGET_PHYS_MASK (bits 0-47) when
extracting the base address from a directory entry.  This retained flag
bits (V, D, PLV, MAT, etc.) at positions 0-11, which were then OR'd
For LoongArch, what is scenery with DIR/PTE entry where bit0-bit11 such 
as (V, D, PLV, MAT, etc.) is used, except Huge bit?

Regards
Bibo Mao
with the next-level index, producing a wrong physical address whenever
the directory entry carried non-zero flags.

Fix both helpers to extract only the PPN field (bits 12-47) before
computing the address of the next-level page table entry.

Signed-off-by: numpy1314 <xz...@mail.ustc.edu.cn>
Signed-off-by: SignKirigami <prc...@krgm.moe>
---
This patch is a resend of [1], Sorry for wrongly handling Signed-off-by.
  
[1]: https://lists.gnu.org/archive/html/qemu-devel/2026-09/msg05581.html.
  
  target/loongarch/tcg/tlb_helper.c | 7 ++-----
  1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/target/loongarch/tcg/tlb_helper.c 
b/target/loongarch/tcg/tlb_helper.c
index 40cc076424..529b22347d 100644
--- a/target/loongarch/tcg/tlb_helper.c
+++ b/target/loongarch/tcg/tlb_helper.c
@@ -750,7 +750,7 @@ target_ulong helper_lddir(CPULoongArchState *env, 
target_ulong base,
      }
  
      badvaddr = sys->CSR_TLBRBADV;
-    base = base & palen_mask;
+    base = base & palen_mask & ~MAKE_64BIT_MASK(0, 12);
      get_dir_base_width(env, &dir_base, &dir_width, level);
      index = (badvaddr >> dir_base) & ((1 << dir_width) - 1);
      phys = base | index << 3;
@@ -773,7 +773,6 @@ void helper_ldpte(CPULoongArchState *env, target_ulong 
base, target_ulong odd,
      uint64_t dir_base, dir_width;
      uint8_t  ps;
  
-
      /*
       * The parameter "base" has only two types,
       * one is the page table base address,
@@ -815,9 +814,7 @@ void helper_ldpte(CPULoongArchState *env, target_ulong 
base, target_ulong odd,
          }
      } else {
          badv = sys->CSR_TLBRBADV;
-
-        base = base & palen_mask;
-
+        base = base & palen_mask & ~MAKE_64BIT_MASK(0, 12);
          ptindex = (badv >> ptbase) & ((1 << ptwidth) - 1);
          ptindex = ptindex & ~0x1;   /* clear bit 0 */
          ptoffset0 = ptindex << 3;