[Qemu-devel] [RFC v1 03/23] target/riscv: Add the virtulisation mode

[Alistair Francis]

Signed-off-by: Alistair Francis <address@hidden>
---
 target/riscv/cpu.h        |  4 ++++
 target/riscv/cpu_bits.h   |  6 ++++++
 target/riscv/cpu_helper.c | 23 +++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 3337d1aef3..de4843b879 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -132,6 +132,8 @@ 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;
@@ -278,6 +280,8 @@ void riscv_cpu_do_interrupt(CPUState *cpu);
 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_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 dc9d53d4be..07c95e8d2c 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -417,6 +417,12 @@
 #define PRV_H 2 /* Reserved */
 #define PRV_M 3
 
+/* Virtulisation modes */
+#define VIRT_OFF            0
+#define VIRT_ON             1
+#define VIRT_MODE_SHIFT     0
+#define VIRT_MODE_MASK      (1 << VIRT_MODE_SHIFT)
+
 /* 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 872835177a..5912ae63b7 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -71,6 +71,29 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int 
interrupt_request)
 
 #if !defined(CONFIG_USER_ONLY)
 
+bool riscv_cpu_virt_enabled(CPURISCVState *env)
+{
+    bool tmp;
+
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    tmp = (env->virt & VIRT_MODE_MASK) >> VIRT_MODE_SHIFT;
+
+    return tmp == VIRT_ON;
+}
+
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt &= ~VIRT_MODE_MASK;
+    env->virt |= enable << VIRT_MODE_SHIFT;
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
2.21.0