target/riscv: Update VS timer whenever htimedelta changes

The htimedelta[h] CSR has impact on the VS timer comparison so we
should call riscv_timer_write_timecmp() whenever htimedelta changes.

Fixes: 3ec0fe18a3 ("target/riscv: Add vstimecmp suppor")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120125950.2246378-2-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/csr.c

@@ -3045,6 +3045,8 @@ static RISCVException read_htimedelta(CPURISCVState *env, int csrno,
 static RISCVException write_htimedelta(CPURISCVState *env, int csrno,
                                        target_ulong val)
 {
+    RISCVCPU *cpu = env_archcpu(env);
+
     if (!env->rdtime_fn) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
@@ -3054,6 +3056,12 @@ static RISCVException write_htimedelta(CPURISCVState *env, int csrno,
     } else {
         env->htimedelta = val;
     }
+
+    if (cpu->cfg.ext_sstc && env->rdtime_fn) {
+        riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
+                                  env->htimedelta, MIP_VSTIP);
+    }
+
     return RISCV_EXCP_NONE;
 }
 
@@ -3071,11 +3079,19 @@ static RISCVException read_htimedeltah(CPURISCVState *env, int csrno,
 static RISCVException write_htimedeltah(CPURISCVState *env, int csrno,
                                         target_ulong val)
 {
+    RISCVCPU *cpu = env_archcpu(env);
+
     if (!env->rdtime_fn) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
 
     env->htimedelta = deposit64(env->htimedelta, 32, 32, (uint64_t)val);
+
+    if (cpu->cfg.ext_sstc && env->rdtime_fn) {
+        riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
+                                  env->htimedelta, MIP_VSTIP);
+    }
+
     return RISCV_EXCP_NONE;
 }