target/riscv: Add the virtulisation mode

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

3 files changed, 25 insertions, 0 deletions

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index c7f7ae5..a9cbd85 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -117,6 +117,8 @@ struct CPURISCVState {
 
 #ifndef CONFIG_USER_ONLY
     target_ulong priv;
+    /* This contains QEMU specific information about the virt state. */
+    target_ulong virt;
     target_ulong resetvec;
 
     target_ulong mhartid;
@@ -269,6 +271,8 @@ int riscv_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
 int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_fp_enabled(CPURISCVState *env);
+bool riscv_cpu_virt_enabled(CPURISCVState *env);
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index eeaa03c..2cdb0de 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -430,6 +430,9 @@
 #define PRV_H 2 /* Reserved */
 #define PRV_M 3
 
+/* Virtulisation Register Fields */
+#define VIRT_ONOFF          1
+
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
 #define SATP32_ASID         0x7fc00000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index a10582b..e531116 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,24 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+bool riscv_cpu_virt_enabled(CPURISCVState *env)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    return get_field(env->virt, VIRT_ONOFF);
+}
+
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt = set_field(env->virt, VIRT_ONOFF, enable);
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;