[PATCH] target/riscv: Implement PMU CSR predicate function for U-mode

[Aurelien Jarno]

Recently the Linux kernel started to use a non default value, for
the scounteren CSR, which is ignored by QEMU. Fix that by implementing
the PMU CSR predicate function for U-mode.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 target/riscv/csr.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 235f2a011e..8aba1b35d9 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -137,6 +137,55 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
                 break;
             }
         }
+    } else if (env->priv == PRV_U) {
+        switch (csrno) {
+        case CSR_CYCLE:
+            if (!get_field(env->scounteren, COUNTEREN_CY)) {
+                return RISCV_EXCP_ILLEGAL_INST;
+            }
+            break;
+        case CSR_TIME:
+            if (!get_field(env->scounteren, COUNTEREN_TM)) {
+                return RISCV_EXCP_ILLEGAL_INST;
+            }
+            break;
+        case CSR_INSTRET:
+            if (!get_field(env->scounteren, COUNTEREN_IR)) {
+                return RISCV_EXCP_ILLEGAL_INST;
+            }
+            break;
+        case CSR_HPMCOUNTER3...CSR_HPMCOUNTER31:
+            ctr_index = csrno - CSR_CYCLE;
+            if (!get_field(env->scounteren, 1 << ctr_index)) {
+                return RISCV_EXCP_ILLEGAL_INST;
+            }
+            break;
+        }
+        if (rv32) {
+            switch (csrno) {
+            case CSR_CYCLEH:
+                if (!get_field(env->scounteren, COUNTEREN_CY)) {
+                    return RISCV_EXCP_ILLEGAL_INST;
+                }
+                break;
+            case CSR_TIMEH:
+                if (!get_field(env->scounteren, COUNTEREN_TM)) {
+                    return RISCV_EXCP_ILLEGAL_INST;
+                }
+                break;
+            case CSR_INSTRETH:
+                if (!get_field(env->scounteren, COUNTEREN_IR)) {
+                    return RISCV_EXCP_ILLEGAL_INST;
+                }
+                break;
+            case CSR_HPMCOUNTER3H...CSR_HPMCOUNTER31H:
+                ctr_index = csrno - CSR_CYCLEH;
+                if (!get_field(env->scounteren, 1 << ctr_index)) {
+                    return RISCV_EXCP_ILLEGAL_INST;
+                }
+                break;
+            }
+        }
     }
 
     if (riscv_cpu_virt_enabled(env)) {
-- 
2.35.1