Check that the argument to set_satp_mode_max_supported is valid for
the MXL value of the CPU.  It would be a bug in the CPU definition
if it weren't.

In fact, there is such a bug in riscv_bare_cpu_init(): not just
SV64 is not a valid VM mode for 32-bit CPUs, SV64 is not a
valid VM mode at all, not yet at least.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/riscv/cpu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index e0604f4c78b..e0e70a2227f 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -445,6 +445,8 @@ static void set_satp_mode_max_supported(RISCVCPU *cpu,
             cpu->cfg.satp_mode.supported |= (1 << i);
         }
     }
+
+    assert(cpu->cfg.satp_mode.supported & (1 << satp_mode));
 }
 
 /* Set the satp mode to the max supported */
@@ -1498,7 +1500,9 @@ static void riscv_bare_cpu_init(Object *obj)
      * satp_mode manually (see set_satp_mode_default()).
      */
 #ifndef CONFIG_USER_ONLY
-    set_satp_mode_max_supported(cpu, VM_1_10_SV64);
+    set_satp_mode_max_supported(RISCV_CPU(obj),
+        riscv_cpu_mxl(&RISCV_CPU(obj)->env) == MXL_RV32 ?
+        VM_1_10_SV32 : VM_1_10_SV57);
 #endif
 }
 
-- 
2.49.0