Packed extension is default off. The only way to use packed extension is
1. use cpu rv32 or rv64
2. turn on it by command line
   "-cpu rv64,x-p=true,Zp64=true,pext_spec=v0.9.2".

Zp64 is whether to support Zp64 extension, default value is true.
pext_ver is the packed specification version, default value is v0.9.2.
These properties can be specified with other values.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
---
 target/riscv/cpu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1b99f629ec..a94cef1cd1 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -573,13 +573,16 @@ static Property riscv_cpu_properties[] = {
     /* This is experimental so mark with 'x-' */
     DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
     DEFINE_PROP_BOOL("x-v", RISCVCPU, cfg.ext_v, false),
+    DEFINE_PROP_BOOL("x-p", RISCVCPU, cfg.ext_p, false),
     DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
+    DEFINE_PROP_STRING("pext_spec", RISCVCPU, cfg.pext_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
     DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
+    DEFINE_PROP_BOOL("Zp64", RISCVCPU, cfg.ext_p64, true),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
     DEFINE_PROP_UINT64("resetvec", RISCVCPU, cfg.resetvec, DEFAULT_RSTVEC),
-- 
2.17.1