target/riscv: update max_satp_mode based on QOM properties

Almost all users of cpu->cfg.satp_mode care about the "max" value
satp_mode_max_from_map(cpu->cfg.satp_mode.map).  Convert the QOM
properties back into it.  For TCG, deduce the bitmap of supported modes
from valid_vm[].

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/riscv/virt-acpi-build.c

@@ -287,7 +287,6 @@ static void build_rhct(GArray *table_data,
     uint32_t isa_offset, num_rhct_nodes, cmo_offset = 0;
     RISCVCPU *cpu = &s->soc[0].harts[0];
     uint32_t mmu_offset = 0;
-    uint8_t satp_mode_max;
     bool rv32 = riscv_cpu_is_32bit(cpu);
     g_autofree char *isa = NULL;
 
@@ -308,8 +307,7 @@ static void build_rhct(GArray *table_data,
         num_rhct_nodes++;
     }
 
-    if (!rv32 && cpu->cfg.satp_mode.supported != 0 &&
-        (cpu->cfg.satp_mode.map & ~(1 << VM_1_10_MBARE))) {
+    if (!rv32 && cpu->cfg.max_satp_mode >= VM_1_10_SV39) {
         num_rhct_nodes++;
     }
 
@@ -369,20 +367,18 @@ static void build_rhct(GArray *table_data,
     }
 
     /* MMU node structure */
-    if (!rv32 && cpu->cfg.satp_mode.supported != 0 &&
-        (cpu->cfg.satp_mode.map & ~(1 << VM_1_10_MBARE))) {
-        satp_mode_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map);
+    if (!rv32 && cpu->cfg.max_satp_mode >= VM_1_10_SV39) {
         mmu_offset = table_data->len - table.table_offset;
         build_append_int_noprefix(table_data, 2, 2);    /* Type */
         build_append_int_noprefix(table_data, 8, 2);    /* Length */
         build_append_int_noprefix(table_data, 0x1, 2);  /* Revision */
         build_append_int_noprefix(table_data, 0, 1);    /* Reserved */
         /* MMU Type */
-        if (satp_mode_max == VM_1_10_SV57) {
+        if (cpu->cfg.max_satp_mode == VM_1_10_SV57) {
             build_append_int_noprefix(table_data, 2, 1);    /* Sv57 */
-        } else if (satp_mode_max == VM_1_10_SV48) {
+        } else if (cpu->cfg.max_satp_mode == VM_1_10_SV48) {
             build_append_int_noprefix(table_data, 1, 1);    /* Sv48 */
-        } else if (satp_mode_max == VM_1_10_SV39) {
+        } else if (cpu->cfg.max_satp_mode == VM_1_10_SV39) {
             build_append_int_noprefix(table_data, 0, 1);    /* Sv39 */
         } else {
             g_assert_not_reached();

hw/riscv/virt.c

@@ -237,10 +237,10 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int socket,
     uint32_t cpu_phandle;
     MachineState *ms = MACHINE(s);
     bool is_32_bit = riscv_is_32bit(&s->soc[0]);
-    uint8_t satp_mode_max;
 
     for (cpu = s->soc[socket].num_harts - 1; cpu >= 0; cpu--) {
         RISCVCPU *cpu_ptr = &s->soc[socket].harts[cpu];
+        int8_t satp_mode_max = cpu_ptr->cfg.max_satp_mode;
         g_autofree char *cpu_name = NULL;
         g_autofree char *core_name = NULL;
         g_autofree char *intc_name = NULL;
@@ -252,8 +252,7 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int socket,
             s->soc[socket].hartid_base + cpu);
         qemu_fdt_add_subnode(ms->fdt, cpu_name);
 
-        if (cpu_ptr->cfg.satp_mode.supported != 0) {
-            satp_mode_max = satp_mode_max_from_map(cpu_ptr->cfg.satp_mode.map);
+        if (satp_mode_max != -1) {
             sv_name = g_strdup_printf("riscv,%s",
                                       satp_mode_str(satp_mode_max, is_32_bit));
             qemu_fdt_setprop_string(ms->fdt, cpu_name, "mmu-type", sv_name);

target/riscv/cpu.c

@@ -389,7 +389,7 @@ static uint8_t satp_mode_from_str(const char *satp_mode_str)
     g_assert_not_reached();
 }
 
-uint8_t satp_mode_max_from_map(uint32_t map)
+static uint8_t satp_mode_max_from_map(uint32_t map)
 {
     /*
      * 'map = 0' will make us return (31 - 32), which C will
@@ -455,15 +455,13 @@ static void set_satp_mode_default_map(RISCVCPU *cpu)
     /*
      * Bare CPUs do not default to the max available.
      * Users must set a valid satp_mode in the command
-     * line.
+     * line.  Otherwise, leave the existing max_satp_mode
+     * in place.
      */
     if (object_dynamic_cast(OBJECT(cpu), TYPE_RISCV_BARE_CPU) != NULL) {
         warn_report("No satp mode set. Defaulting to 'bare'");
-        cpu->cfg.satp_mode.map = (1 << VM_1_10_MBARE);
-        return;
+        cpu->cfg.max_satp_mode = VM_1_10_MBARE;
     }
-
-    cpu->cfg.satp_mode.map = cpu->cfg.satp_mode.supported;
 }
 #endif
 
@@ -1175,8 +1173,8 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp)
     bool rv32 = riscv_cpu_is_32bit(cpu);
     uint8_t satp_mode_map_max;
 
-    /* The CPU wants the OS to decide which satp mode to use */
-    if (cpu->cfg.satp_mode.supported == 0) {
+    if (cpu->cfg.max_satp_mode == -1) {
+        /* The CPU wants the hypervisor to decide which satp mode to allow */
         return;
     }
 
@@ -1195,14 +1193,14 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp)
                     (cpu->cfg.satp_mode.supported & (1 << i))) {
                     for (int j = i - 1; j >= 0; --j) {
                         if (cpu->cfg.satp_mode.supported & (1 << j)) {
-                            cpu->cfg.satp_mode.map |= (1 << j);
-                            break;
+                            cpu->cfg.max_satp_mode = j;
+                            return;
                         }
                     }
-                    break;
                 }
             }
         }
+        return;
     }
 
     satp_mode_map_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map);
@@ -1232,12 +1230,7 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp)
         }
     }
 
-    /* Finally expand the map so that all valid modes are set */
-    for (int i = satp_mode_map_max - 1; i >= 0; --i) {
-        if (cpu->cfg.satp_mode.supported & (1 << i)) {
-            cpu->cfg.satp_mode.map |= (1 << i);
-        }
-    }
+    cpu->cfg.max_satp_mode = satp_mode_map_max;
 }
 #endif
 

target/riscv/cpu.h

@@ -930,7 +930,6 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs);
 target_ulong riscv_new_csr_seed(target_ulong new_value,
                                 target_ulong write_mask);
 
-uint8_t satp_mode_max_from_map(uint32_t map);
 const char *satp_mode_str(uint8_t satp_mode, bool is_32_bit);
 
 /* Implemented in th_csr.c */

target/riscv/csr.c

@@ -1912,8 +1912,13 @@ static RISCVException read_mstatus(CPURISCVState *env, int csrno,
 
 static bool validate_vm(CPURISCVState *env, target_ulong vm)
 {
-    uint64_t mode_supported = riscv_cpu_cfg(env)->satp_mode.map;
-    return get_field(mode_supported, (1 << vm));
+    bool rv32 = riscv_cpu_mxl(env) == MXL_RV32;
+    RISCVCPU *cpu = env_archcpu(env);
+    int satp_mode_supported_max = cpu->cfg.max_satp_mode;
+    const bool *valid_vm = rv32 ? valid_vm_1_10_32 : valid_vm_1_10_64;
+
+    assert(satp_mode_supported_max >= 0);
+    return vm <= satp_mode_supported_max && valid_vm[vm];
 }
 
 static target_ulong legalize_xatp(CPURISCVState *env, target_ulong old_xatp,