3 files changed, 23 insertions, 0 deletions
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 0c58c8571f..a2881bfa38 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -884,6 +884,17 @@ static void riscv_cpu_reset_hold(Object *obj)
     }
     /* mmte is supposed to have pm.current hardwired to 1 */
     env->mmte |= (EXT_STATUS_INITIAL | MMTE_M_PM_CURRENT);
+
+    /*
+     * Clear mseccfg and unlock all the PMP entries upon reset.
+     * This is allowed as per the priv and smepmp specifications
+     * and is needed to clear stale entries across reboots.
+     */
+    if (riscv_cpu_cfg(env)->ext_smepmp) {
+        env->mseccfg = 0;
+    }
+
+    pmp_unlock_entries(env);
 #endif
     env->xl = riscv_cpu_mxl(env);
     riscv_cpu_update_mask(env);
diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 21d2489e27..4dfaa28fce 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -135,6 +135,16 @@ static bool pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t val)
     return false;
 }
 
+void pmp_unlock_entries(CPURISCVState *env)
+{
+    uint32_t pmp_num = pmp_get_num_rules(env);
+    int i;
+
+    for (i = 0; i < pmp_num; i++) {
+        env->pmp_state.pmp[i].cfg_reg &= ~(PMP_LOCK | PMP_AMATCH);
+    }
+}
+
 static void pmp_decode_napot(target_ulong a, target_ulong *sa,
                              target_ulong *ea)
 {
diff --git a/target/riscv/pmp.h b/target/riscv/pmp.h
index cf5c99f8e6..9af8614cd4 100644
--- a/target/riscv/pmp.h
+++ b/target/riscv/pmp.h
@@ -28,6 +28,7 @@ typedef enum {
     PMP_READ  = 1 << 0,
     PMP_WRITE = 1 << 1,
     PMP_EXEC  = 1 << 2,
+    PMP_AMATCH = (3 << 3),
     PMP_LOCK  = 1 << 7
 } pmp_priv_t;
 
@@ -81,6 +82,7 @@ void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index);
 void pmp_update_rule_nums(CPURISCVState *env);
 uint32_t pmp_get_num_rules(CPURISCVState *env);
 int pmp_priv_to_page_prot(pmp_priv_t pmp_priv);
+void pmp_unlock_entries(CPURISCVState *env);
 
 #define MSECCFG_MML_ISSET(env) get_field(env->mseccfg, MSECCFG_MML)
 #define MSECCFG_MMWP_ISSET(env) get_field(env->mseccfg, MSECCFG_MMWP)