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-rw-r--r--target/riscv/cpu.h3
-rw-r--r--target/riscv/cpu_bits.h3
-rw-r--r--target/riscv/cpu_helper.c10
-rw-r--r--target/riscv/translate.c23
4 files changed, 39 insertions, 0 deletions
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 67ce6e0a03..c3a03f878b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -622,6 +622,9 @@ FIELD(TB_FLAGS, ITRIGGER, 22, 1)
 FIELD(TB_FLAGS, VIRT_ENABLED, 23, 1)
 FIELD(TB_FLAGS, PRIV, 24, 2)
 FIELD(TB_FLAGS, AXL, 26, 2)
+/* zicfilp needs a TB flag to track indirect branches */
+FIELD(TB_FLAGS, FCFI_ENABLED, 28, 1)
+FIELD(TB_FLAGS, FCFI_LP_EXPECTED, 29, 1)
 
 #ifdef TARGET_RISCV32
 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 8df6043ef1..e7387c9b8f 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -692,6 +692,9 @@ typedef enum RISCVException {
     RISCV_EXCP_SEMIHOST = 0x3f,
 } RISCVException;
 
+/* zicfilp defines lp violation results in sw check with tval = 2*/
+#define RISCV_EXCP_SW_CHECK_FCFI_TVAL      2
+
 #define RISCV_EXCP_INT_FLAG                0x80000000
 #define RISCV_EXCP_INT_MASK                0x7fffffff
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index fa4982e940..6a63c37083 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -132,6 +132,16 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc,
         flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
     }
 
+    if (cpu_get_fcfien(env)) {
+        /*
+         * For Forward CFI, only the expectation of a lpad at
+         * the start of the block is tracked via env->elp. env->elp
+         * is turned on during jalr translation.
+         */
+        flags = FIELD_DP32(flags, TB_FLAGS, FCFI_LP_EXPECTED, env->elp);
+        flags = FIELD_DP32(flags, TB_FLAGS, FCFI_ENABLED, 1);
+    }
+
 #ifdef CONFIG_USER_ONLY
     fs = EXT_STATUS_DIRTY;
     vs = EXT_STATUS_DIRTY;
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index acba90f170..b5c0511b4b 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -116,6 +116,9 @@ typedef struct DisasContext {
     bool frm_valid;
     bool insn_start_updated;
     const GPtrArray *decoders;
+    /* zicfilp extension. fcfi_enabled, lp expected or not */
+    bool fcfi_enabled;
+    bool fcfi_lp_expected;
 } DisasContext;
 
 static inline bool has_ext(DisasContext *ctx, uint32_t ext)
@@ -1238,6 +1241,8 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
     ctx->ztso = cpu->cfg.ext_ztso;
     ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
+    ctx->fcfi_lp_expected = FIELD_EX32(tb_flags, TB_FLAGS, FCFI_LP_EXPECTED);
+    ctx->fcfi_enabled = FIELD_EX32(tb_flags, TB_FLAGS, FCFI_ENABLED);
     ctx->zero = tcg_constant_tl(0);
     ctx->virt_inst_excp = false;
     ctx->decoders = cpu->decoders;
@@ -1270,6 +1275,24 @@ static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     decode_opc(env, ctx, opcode16);
     ctx->base.pc_next += ctx->cur_insn_len;
 
+    /*
+     * If 'fcfi_lp_expected' is still true after processing the instruction,
+     * then we did not see an 'lpad' instruction, and must raise an exception.
+     * Insert code to raise the exception at the start of the insn; any other
+     * code the insn may have emitted will be deleted as dead code following
+     * the noreturn exception
+     */
+    if (ctx->fcfi_lp_expected) {
+        /* Emit after insn_start, i.e. before the op following insn_start. */
+        tcg_ctx->emit_before_op = QTAILQ_NEXT(ctx->base.insn_start, link);
+        tcg_gen_st_tl(tcg_constant_tl(RISCV_EXCP_SW_CHECK_FCFI_TVAL),
+                      tcg_env, offsetof(CPURISCVState, sw_check_code));
+        gen_helper_raise_exception(tcg_env,
+                      tcg_constant_i32(RISCV_EXCP_SW_CHECK));
+        tcg_ctx->emit_before_op = NULL;
+        ctx->base.is_jmp = DISAS_NORETURN;
+    }
+
     /* Only the first insn within a TB is allowed to cross a page boundary. */
     if (ctx->base.is_jmp == DISAS_NEXT) {
         if (ctx->itrigger || !is_same_page(&ctx->base, ctx->base.pc_next)) {