RISC-V: Update address bits to support sv39 and sv48

Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.h

@@ -24,12 +24,12 @@
 #define TARGET_PAGE_BITS 12 /* 4 KiB Pages */
 #if defined(TARGET_RISCV64)
 #define TARGET_LONG_BITS 64
-#define TARGET_PHYS_ADDR_SPACE_BITS 50
-#define TARGET_VIRT_ADDR_SPACE_BITS 39
+#define TARGET_PHYS_ADDR_SPACE_BITS 56 /* 44-bit PPN */
+#define TARGET_VIRT_ADDR_SPACE_BITS 48 /* sv48 */
 #elif defined(TARGET_RISCV32)
 #define TARGET_LONG_BITS 32
-#define TARGET_PHYS_ADDR_SPACE_BITS 34
-#define TARGET_VIRT_ADDR_SPACE_BITS 32
+#define TARGET_PHYS_ADDR_SPACE_BITS 34 /* 22-bit PPN */
+#define TARGET_VIRT_ADDR_SPACE_BITS 32 /* sv32 */
 #endif
 
 #define TCG_GUEST_DEFAULT_MO 0