Re: [PATCH v1 29/43] target/loongarch: Add timer related instructions support.

[Richard Henderson]

On 4/15/22 02:40, Xiaojuan Yang wrote:
+uint64_t helper_rdtime_d(CPULoongArchState *env)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(env_cpu(env));
+
+    if ((env->CSR_MISC >> 7) & 0x1) {
+        do_raise_exception(env, EXCCODE_IPE, GETPC());

This isn't correct -- you need to extract bit 4 + plv.  It would be better to add CSR_MISC 
fields to cpu-csr.h rather than hard-code a constant.  If you treat them as the 4-bit 
fields that they are,

FIELD(CSR_MISC, VA32, 0, 4)
FIELD(CSR_MISC, DRDTL, 4, 4)
etc

then here,

    plv = FIELD_EX64(env->CSR_CRMD, CSR_CRMD, PLV);
    if (extract64(env->CSR_MISC, R_CSR_MISC_DRDTL_SHIFT + plv, 1))


r~