[PATCH] target/riscv: Force to set mstatus_hs.[SD|FS] bits in mark_fs_dirty()

[frank . chang]

From: Frank Chang <frank.ch...@sifive.com>

When V=1, both vsstauts.FS and HS-level sstatus.FS are in effect.
Modifying the floating-point state when V=1 causes both fields to
be set to 3 (Dirty).

However, it's possible that HS-level sstatus.FS is Clean and VS-level
vsstatus.FS is Dirty at the time mark_fs_dirty() is called when V=1.
We can't early return for this case because we still need to set
sstatus.FS to Dirty according to spec.

Signed-off-by: Frank Chang <frank.ch...@sifive.com>
Reviewed-by: Vincent Chen <vincent.c...@sifive.com>
Tested-by: Vincent Chen <vincent.c...@sifive.com>
---
 target/riscv/translate.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index e356fc6c46c..0096b098738 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -280,26 +280,27 @@ static void gen_jal(DisasContext *ctx, int rd, 
target_ulong imm)
 static void mark_fs_dirty(DisasContext *ctx)
 {
     TCGv tmp;
-    target_ulong sd;
+    target_ulong sd = is_32bit(ctx) ? MSTATUS32_SD : MSTATUS64_SD;
+
+    if (ctx->virt_enabled) {
+        tmp = tcg_temp_new();
+        tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
+        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | sd);
+        tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
+        tcg_temp_free(tmp);
+    }
 
     if (ctx->mstatus_fs == MSTATUS_FS) {
         return;
     }
+
     /* Remember the state change for the rest of the TB.  */
     ctx->mstatus_fs = MSTATUS_FS;
 
     tmp = tcg_temp_new();
-    sd = is_32bit(ctx) ? MSTATUS32_SD : MSTATUS64_SD;
-
     tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
     tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | sd);
     tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
-
-    if (ctx->virt_enabled) {
-        tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
-        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | sd);
-        tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
-    }
     tcg_temp_free(tmp);
 }
 #else
-- 
2.25.1