[PATCH v4 2/6] target/riscv: Support senvcfg[UKTE] bit when svukte extension is enabled

[Fea.Wang]

Svukte extension add UKTE bit, bit[8] in senvcfg CSR. The bit will be
supported when the svukte extension is enabled.

When senvcfg[UKTE] bit is set, the memory access from U-mode should do
the svukte check only except HLV/HLVX/HSV H-mode instructions which
depend on hstatus[HUKTE].

Signed-off-by: Fea.Wang <fea.wang@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_bits.h | 1 +
 target/riscv/csr.c      | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 385a2c67c2..4b9f899217 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -785,6 +785,7 @@ typedef enum RISCVException {
 #define SENVCFG_CBIE                       MENVCFG_CBIE
 #define SENVCFG_CBCFE                      MENVCFG_CBCFE
 #define SENVCFG_CBZE                       MENVCFG_CBZE
+#define SENVCFG_UKTE                       BIT(8)
 
 #define HENVCFG_FIOM                       MENVCFG_FIOM
 #define HENVCFG_LPE                        MENVCFG_LPE
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 9846770820..1936a6f32a 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -2453,6 +2453,10 @@ static RISCVException write_senvcfg(CPURISCVState *env, 
int csrno,
         mask |= SENVCFG_SSE;
     }
 
+    if (env_archcpu(env)->cfg.ext_svukte) {
+        mask |= SENVCFG_UKTE;
+    }
+
     env->senvcfg = (env->senvcfg & ~mask) | (val & mask);
     return RISCV_EXCP_NONE;
 }
-- 
2.34.1