target/riscv: Add PMP state description

In the case of supporting PMP feature, add PMP state description
to vmstate_riscv_cpu.

'vmstate_pmp_addr' and 'num_rules' could be regenerated by
pmp_update_rule(). But there exists the problem of updating
num_rules repeatedly in pmp_update_rule(). So here extracts
pmp_update_rule_addr() and pmp_update_rule_nums() to update
'vmstate_pmp_addr' and 'num_rules' respectively.

Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-4-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/machine.c

@@ -22,6 +22,52 @@
 #include "sysemu/kvm.h"
 #include "migration/cpu.h"
 
+static bool pmp_needed(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    CPURISCVState *env = &cpu->env;
+
+    return riscv_feature(env, RISCV_FEATURE_PMP);
+}
+
+static int pmp_post_load(void *opaque, int version_id)
+{
+    RISCVCPU *cpu = opaque;
+    CPURISCVState *env = &cpu->env;
+    int i;
+
+    for (i = 0; i < MAX_RISCV_PMPS; i++) {
+        pmp_update_rule_addr(env, i);
+    }
+    pmp_update_rule_nums(env);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_pmp_entry = {
+    .name = "cpu/pmp/entry",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINTTL(addr_reg, pmp_entry_t),
+        VMSTATE_UINT8(cfg_reg, pmp_entry_t),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_pmp = {
+    .name = "cpu/pmp",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = pmp_needed,
+    .post_load = pmp_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT_ARRAY(env.pmp_state.pmp, RISCVCPU, MAX_RISCV_PMPS,
+                             0, vmstate_pmp_entry, pmp_entry_t),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_riscv_cpu = {
     .name = "cpu",
     .version_id = 1,
@@ -70,5 +116,9 @@ const VMStateDescription vmstate_riscv_cpu = {
         VMSTATE_UINT64(env.timecmp, RISCVCPU),
 
         VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription * []) {
+        &vmstate_pmp,
+        NULL
     }
 };

target/riscv/pmp.c

@@ -136,18 +136,8 @@ static void pmp_decode_napot(target_ulong a, target_ulong *sa, target_ulong *ea)
     }
 }
 
-
-/* Convert cfg/addr reg values here into simple 'sa' --> start address and 'ea'
- *   end address values.
- *   This function is called relatively infrequently whereas the check that
- *   an address is within a pmp rule is called often, so optimise that one
- */
-static void pmp_update_rule(CPURISCVState *env, uint32_t pmp_index)
+void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index)
 {
-    int i;
-
-    env->pmp_state.num_rules = 0;
-
     uint8_t this_cfg = env->pmp_state.pmp[pmp_index].cfg_reg;
     target_ulong this_addr = env->pmp_state.pmp[pmp_index].addr_reg;
     target_ulong prev_addr = 0u;
@@ -186,7 +176,13 @@ static void pmp_update_rule(CPURISCVState *env, uint32_t pmp_index)
 
     env->pmp_state.addr[pmp_index].sa = sa;
     env->pmp_state.addr[pmp_index].ea = ea;
+}
 
+void pmp_update_rule_nums(CPURISCVState *env)
+{
+    int i;
+
+    env->pmp_state.num_rules = 0;
     for (i = 0; i < MAX_RISCV_PMPS; i++) {
         const uint8_t a_field =
             pmp_get_a_field(env->pmp_state.pmp[i].cfg_reg);
@@ -196,6 +192,17 @@ static void pmp_update_rule(CPURISCVState *env, uint32_t pmp_index)
     }
 }
 
+/* Convert cfg/addr reg values here into simple 'sa' --> start address and 'ea'
+ *   end address values.
+ *   This function is called relatively infrequently whereas the check that
+ *   an address is within a pmp rule is called often, so optimise that one
+ */
+static void pmp_update_rule(CPURISCVState *env, uint32_t pmp_index)
+{
+    pmp_update_rule_addr(env, pmp_index);
+    pmp_update_rule_nums(env);
+}
+
 static int pmp_is_in_range(CPURISCVState *env, int pmp_index, target_ulong addr)
 {
     int result = 0;

target/riscv/pmp.h

@@ -62,5 +62,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
     target_ulong size, pmp_priv_t priv, target_ulong mode);
 bool pmp_is_range_in_tlb(CPURISCVState *env, hwaddr tlb_sa,
                          target_ulong *tlb_size);
+void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index);
+void pmp_update_rule_nums(CPURISCVState *env);
 
 #endif