[PATCH v8] target/hexagon: Add privilege check, use tag_ignore()

[Brian Cain <brian.cain@oss.qualcomm.com>]

Add system event and cause code definitions needed for exception
handling in sysemu mode.  Add privilege checks that raise exceptions
for guest/supervisor-only instructions executed without appropriate
privilege.

Expose hex_gen_exception_end_tb() via translate.h (previously the
static gen_exception_end_tb) so that it can be called from the
generated privileged-instruction TCG stubs.

Reviewed-by: Taylor Simpson <ltaylorsimpson@gmail.com>
Signed-off-by: Brian Cain <brian.cain@oss.qualcomm.com>
---
 target/hexagon/cpu.h            | 10 +++++
 target/hexagon/cpu_bits.h       | 75 +++++++++++++++++++++++++++++----
 target/hexagon/translate.h      |  2 +
 linux-user/hexagon/cpu_loop.c   | 16 +++++++
 target/hexagon/cpu.c            |  1 +
 target/hexagon/translate.c      | 12 +++++-
 target/hexagon/gen_tcg_funcs.py | 35 +++++++++------
 7 files changed, 127 insertions(+), 24 deletions(-)

diff --git a/target/hexagon/cpu.h b/target/hexagon/cpu.h
index 7c09c97db85..e22567d8e67 100644
--- a/target/hexagon/cpu.h
+++ b/target/hexagon/cpu.h
@@ -45,6 +45,15 @@
 
 #define MMU_USER_IDX 0
 
+#define HEXAGON_CPU_IRQ_0 0
+#define HEXAGON_CPU_IRQ_1 1
+#define HEXAGON_CPU_IRQ_2 2
+#define HEXAGON_CPU_IRQ_3 3
+#define HEXAGON_CPU_IRQ_4 4
+#define HEXAGON_CPU_IRQ_5 5
+#define HEXAGON_CPU_IRQ_6 6
+#define HEXAGON_CPU_IRQ_7 7
+
 typedef struct {
     target_ulong va;
     uint32_t width;
@@ -77,6 +86,7 @@ typedef struct {
 typedef struct CPUArchState {
     target_ulong gpr[TOTAL_PER_THREAD_REGS];
     target_ulong pred[NUM_PREGS];
+    uint32_t cause_code;
 
     /* For comparing with LLDB on target - see adjust_stack_ptrs function */
     target_ulong last_pc_dumped;
diff --git a/target/hexagon/cpu_bits.h b/target/hexagon/cpu_bits.h
index aaac6b9ea64..164e74c782b 100644
--- a/target/hexagon/cpu_bits.h
+++ b/target/hexagon/cpu_bits.h
@@ -25,20 +25,77 @@
 #define PCALIGN_MASK (PCALIGN - 1)
 
 enum hex_event {
-    HEX_EVENT_NONE           = -1,
-    HEX_EVENT_TRAP0          =  0x008,
+    HEX_EVENT_NONE = -1,
+    HEX_EVENT_RESET = 0x0,
+    HEX_EVENT_IMPRECISE = 0x1,
+    HEX_EVENT_PRECISE = 0x2,
+    HEX_EVENT_TLB_MISS_X = 0x4,
+    HEX_EVENT_TLB_MISS_RW = 0x6,
+    HEX_EVENT_TRAP0 = 0x8,
+    HEX_EVENT_TRAP1 = 0x9,
+    HEX_EVENT_FPTRAP = 0xb,
+    HEX_EVENT_DEBUG = 0xc,
+    HEX_EVENT_INT0 = 0x10,
+    HEX_EVENT_INT1 = 0x11,
+    HEX_EVENT_INT2 = 0x12,
+    HEX_EVENT_INT3 = 0x13,
+    HEX_EVENT_INT4 = 0x14,
+    HEX_EVENT_INT5 = 0x15,
+    HEX_EVENT_INT6 = 0x16,
+    HEX_EVENT_INT7 = 0x17,
+    HEX_EVENT_INT8 = 0x18,
+    HEX_EVENT_INT9 = 0x19,
+    HEX_EVENT_INTA = 0x1a,
+    HEX_EVENT_INTB = 0x1b,
+    HEX_EVENT_INTC = 0x1c,
+    HEX_EVENT_INTD = 0x1d,
+    HEX_EVENT_INTE = 0x1e,
+    HEX_EVENT_INTF = 0x1f,
 };
 
 enum hex_cause {
     HEX_CAUSE_NONE = -1,
-    HEX_CAUSE_TRAP0 = 0x172,
-    HEX_CAUSE_FETCH_NO_UPAGE =  0x012,
-    HEX_CAUSE_INVALID_PACKET =  0x015,
-    HEX_CAUSE_INVALID_OPCODE =  0x015,
+    HEX_CAUSE_RESET = 0x000,
+    HEX_CAUSE_BIU_PRECISE = 0x001,
+    HEX_CAUSE_UNSUPPORTED_HVX_64B = 0x002, /* QEMU-specific */
+    HEX_CAUSE_DOUBLE_EXCEPT = 0x003,
+    HEX_CAUSE_TRAP0 = 0x008,
+    HEX_CAUSE_TRAP1 = 0x009,
+    HEX_CAUSE_FETCH_NO_XPAGE = 0x011,
+    HEX_CAUSE_FETCH_NO_UPAGE = 0x012,
+    HEX_CAUSE_INVALID_PACKET = 0x015,
+    HEX_CAUSE_INVALID_OPCODE = 0x015, /* alias: same cause as INVALID_PACKET */
+    HEX_CAUSE_NO_COPROC_ENABLE = 0x016,
+    HEX_CAUSE_NO_COPROC2_ENABLE = 0x018,
+    HEX_CAUSE_PRIV_USER_NO_GINSN = 0x01a,
+    HEX_CAUSE_PRIV_USER_NO_SINSN = 0x01b,
     HEX_CAUSE_REG_WRITE_CONFLICT = 0x01d,
-    HEX_CAUSE_PC_NOT_ALIGNED =  0x01e,
-    HEX_CAUSE_PRIV_NO_UREAD  =  0x024,
-    HEX_CAUSE_PRIV_NO_UWRITE =  0x025,
+    HEX_CAUSE_PC_NOT_ALIGNED = 0x01e,
+    HEX_CAUSE_MISALIGNED_LOAD = 0x020,
+    HEX_CAUSE_MISALIGNED_STORE = 0x021,
+    HEX_CAUSE_PRIV_NO_READ = 0x022,
+    HEX_CAUSE_PRIV_NO_WRITE = 0x023,
+    HEX_CAUSE_PRIV_NO_UREAD = 0x024,
+    HEX_CAUSE_PRIV_NO_UWRITE = 0x025,
+    HEX_CAUSE_COPROC_LDST = 0x026,
+    HEX_CAUSE_STACK_LIMIT = 0x027,
+    HEX_CAUSE_VWCTRL_WINDOW_MISS = 0x029,
+    HEX_CAUSE_IMPRECISE_NMI = 0x043,
+    HEX_CAUSE_IMPRECISE_MULTI_TLB_MATCH = 0x044,
+    HEX_CAUSE_TLBMISSX_CAUSE_NORMAL = 0x060,
+    HEX_CAUSE_TLBMISSX_CAUSE_NEXTPAGE = 0x061,
+    HEX_CAUSE_TLBMISSRW_CAUSE_READ = 0x070,
+    HEX_CAUSE_TLBMISSRW_CAUSE_WRITE = 0x071,
+    HEX_CAUSE_DEBUG_SINGLESTEP = 0x80,
+    HEX_CAUSE_FPTRAP_CAUSE_BADFLOAT = 0x0bf,
+    HEX_CAUSE_INT0 = 0x0c0,
+    HEX_CAUSE_INT1 = 0x0c1,
+    HEX_CAUSE_INT2 = 0x0c2,
+    HEX_CAUSE_INT3 = 0x0c3,
+    HEX_CAUSE_INT4 = 0x0c4,
+    HEX_CAUSE_INT5 = 0x0c5,
+    HEX_CAUSE_INT6 = 0x0c6,
+    HEX_CAUSE_INT7 = 0x0c7,
 };
 
 #define PACKET_WORDS_MAX         4
diff --git a/target/hexagon/translate.h b/target/hexagon/translate.h
index 1fc185e3edd..d80bc532e24 100644
--- a/target/hexagon/translate.h
+++ b/target/hexagon/translate.h
@@ -283,6 +283,8 @@ extern TCGv hex_vstore_addr[VSTORES_MAX];
 extern TCGv hex_vstore_size[VSTORES_MAX];
 extern TCGv hex_vstore_pending[VSTORES_MAX];
 
+void hex_gen_exception_end_tb(DisasContext *ctx, int excp);
+
 void process_store(DisasContext *ctx, int slot_num);
 
 FIELD(PROBE_PKT_SCALAR_STORE_S0, MMU_IDX,       0, 2)
diff --git a/linux-user/hexagon/cpu_loop.c b/linux-user/hexagon/cpu_loop.c
index 9464246e9e3..9f54c7b3f96 100644
--- a/linux-user/hexagon/cpu_loop.c
+++ b/linux-user/hexagon/cpu_loop.c
@@ -22,6 +22,7 @@
 #include "qemu.h"
 #include "user-internals.h"
 #include "user/cpu_loop.h"
+#include "target/hexagon/internal.h"
 #include "signal-common.h"
 #include "internal.h"
 
@@ -60,6 +61,21 @@ void cpu_loop(CPUHexagonState *env)
                 env->gpr[0] = ret;
             }
             break;
+        case HEX_EVENT_PRECISE:
+            switch (env->cause_code) {
+            case HEX_CAUSE_PRIV_USER_NO_GINSN:
+            case HEX_CAUSE_PRIV_USER_NO_SINSN:
+            case HEX_CAUSE_INVALID_PACKET:
+            force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC,
+                    env->gpr[HEX_REG_PC]);
+            break;
+            default:
+                EXCP_DUMP(env, "\nqemu: unhandled CPU precise exception "
+                    "cause code 0x%x - aborting\n",
+                    env->cause_code);
+                exit(EXIT_FAILURE);
+            }
+            break;
         case HEX_CAUSE_PC_NOT_ALIGNED:
             force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
                             env->gpr[HEX_REG_R31]);
diff --git a/target/hexagon/cpu.c b/target/hexagon/cpu.c
index bd568bdd871..5bf6e85b939 100644
--- a/target/hexagon/cpu.c
+++ b/target/hexagon/cpu.c
@@ -299,6 +299,7 @@ static void hexagon_cpu_reset_hold(Object *obj, ResetType type)
     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
     /* Default NaN value: sign bit set, all frac bits set */
     set_float_default_nan_pattern(0b11111111, &env->fp_status);
+    env->cause_code = HEX_EVENT_NONE;
 }
 
 static void hexagon_cpu_disas_set_info(const CPUState *cs,
diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
index 0b9337d9120..d61658a798c 100644
--- a/target/hexagon/translate.c
+++ b/target/hexagon/translate.c
@@ -65,6 +65,10 @@ TCGv hex_vstore_addr[VSTORES_MAX];
 TCGv hex_vstore_size[VSTORES_MAX];
 TCGv hex_vstore_pending[VSTORES_MAX];
 
+#ifndef CONFIG_USER_ONLY
+TCGv_i32 hex_cause_code;
+#endif
+
 static const char * const hexagon_prednames[] = {
   "p0", "p1", "p2", "p3"
 };
@@ -187,7 +191,7 @@ static void gen_end_tb(DisasContext *ctx)
     ctx->base.is_jmp = DISAS_NORETURN;
 }
 
-static void gen_exception_end_tb(DisasContext *ctx, int excp)
+void hex_gen_exception_end_tb(DisasContext *ctx, int excp)
 {
     gen_exec_counters(ctx);
     tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], ctx->next_PC);
@@ -580,7 +584,7 @@ static void gen_insn(DisasContext *ctx)
         ctx->insn->generate(ctx);
         mark_store_width(ctx);
     } else {
-        gen_exception_end_tb(ctx, HEX_CAUSE_INVALID_OPCODE);
+        hex_gen_exception_end_tb(ctx, HEX_CAUSE_INVALID_OPCODE);
     }
 }
 
@@ -1138,4 +1142,8 @@ void hexagon_translate_init(void)
             offsetof(CPUHexagonState, vstore_pending[i]),
             vstore_pending_names[i]);
     }
+#ifndef CONFIG_USER_ONLY
+    hex_cause_code = tcg_global_mem_new(tcg_env,
+        offsetof(CPUHexagonState, cause_code), "cause_code");
+#endif
 }
diff --git a/target/hexagon/gen_tcg_funcs.py b/target/hexagon/gen_tcg_funcs.py
index e7f90a0da11..6d5d99cee3a 100755
--- a/target/hexagon/gen_tcg_funcs.py
+++ b/target/hexagon/gen_tcg_funcs.py
@@ -21,7 +21,7 @@
 import re
 import string
 import hex_common
-
+from textwrap import dedent
 
 ##
 ## Generate the TCG code to call the helper
@@ -49,6 +49,18 @@ def gen_tcg_func(f, tag, regs, imms):
 
     f.write("    Insn *insn G_GNUC_UNUSED = ctx->insn;\n")
 
+    if "A_PRIV" in hex_common.attribdict[tag]:
+        f.write(dedent("""\
+#ifdef CONFIG_USER_ONLY
+    hex_gen_exception_end_tb(ctx, HEX_CAUSE_PRIV_USER_NO_SINSN);
+#else
+"""))
+    if "A_GUEST" in hex_common.attribdict[tag]:
+        f.write(dedent("""\
+#ifdef CONFIG_USER_ONLY
+    hex_gen_exception_end_tb(ctx, HEX_CAUSE_PRIV_USER_NO_GINSN);
+#else
+"""))
     if hex_common.need_ea(tag):
         f.write("    TCGv EA G_GNUC_UNUSED = tcg_temp_new();\n")
 
@@ -100,6 +112,11 @@ def gen_tcg_func(f, tag, regs, imms):
         if reg.is_written():
             reg.gen_write(f, tag)
 
+    if (
+        "A_PRIV" in hex_common.attribdict[tag]
+        or "A_GUEST" in hex_common.attribdict[tag]
+    ):
+        f.write("#endif   /* CONFIG_USER_ONLY */\n")
     f.write("}\n\n")
 
 
@@ -124,18 +141,10 @@ def main():
             f.write('#include "idef-generated-emitter.h.inc"\n\n')
 
         for tag in hex_common.tags:
-            ## Skip the priv instructions
-            if "A_PRIV" in hex_common.attribdict[tag]:
-                continue
-            ## Skip the guest instructions
-            if "A_GUEST" in hex_common.attribdict[tag]:
-                continue
-            ## Skip the diag instructions
-            if tag == "Y6_diag":
-                continue
-            if tag == "Y6_diag0":
-                continue
-            if tag == "Y6_diag1":
+            if hex_common.tag_ignore(tag):
+                f.write(f"static void generate_{tag}"
+                        f"(DisasContext *ctx)\n")
+                f.write("{\n}\n\n")
                 continue
 
             gen_def_tcg_func(f, tag, tagregs, tagimms)
-- 
2.34.1