Hexagon (target/hexagon) Disassembly of invalid packets

We pass the Hexagon CPU definition to disassemble_hexagon.  This allows
decode_packet to know if the opcodes are supported.

Note that we print valid instructions in a packet when one or more is
invalid.  Rather than this
0x0002128c:  0x1eae4fec	{	<invalid>
0x00021290:  0x1c434c04		<invalid>
0x00021294:  0x1e03edf0		<invalid> }

We print this
0x0002128c:  0x1eae4fec	{	<invalid>
0x00021290:  0x1c434c04		V4.w = vadd(V12.w,V3.w)
0x00021294:  0x1e03edf0		V16 = V13 }

Co-authored-by: Matheus Tavares Bernardino <matheus.bernardino@oss.qualcomm.com>
Co-authored-by: Brian Cain <brian.cain@oss.qualcomm.com>
Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Signed-off-by: Brian Cain <brian.cain@oss.qualcomm.com>

disas/hexagon.c

@@ -31,6 +31,7 @@
 
 int print_insn_hexagon(bfd_vma memaddr, struct disassemble_info *info)
 {
+    const HexagonCPUDef *hex_def = (const HexagonCPUDef *)info->target_info;
     uint32_t words[PACKET_WORDS_MAX];
     bool found_end = false;
     GString *buf;
@@ -58,7 +59,7 @@ int print_insn_hexagon(bfd_vma memaddr, struct disassemble_info *info)
     }
 
     buf = g_string_sized_new(PACKET_BUFFER_LEN);
-    len = disassemble_hexagon(words, i, memaddr, buf);
+    len = disassemble_hexagon(words, i, memaddr, buf, hex_def);
     (*info->fprintf_func)(info->stream, "%s", buf->str);
     g_string_free(buf, true);
 

target/hexagon/cpu.c

@@ -297,8 +297,10 @@ static void hexagon_cpu_reset_hold(Object *obj, ResetType type)
 static void hexagon_cpu_disas_set_info(const CPUState *cs,
                                        disassemble_info *info)
 {
+    const HexagonCPU *cpu = HEXAGON_CPU(cs);
     info->print_insn = print_insn_hexagon;
     info->endian = BFD_ENDIAN_LITTLE;
+    info->target_info = HEXAGON_CPU_GET_CLASS(cpu)->hex_def;
 }
 
 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)

target/hexagon/cpu_bits.h

@@ -19,6 +19,7 @@
 #define HEXAGON_CPU_BITS_H
 
 #include "qemu/bitops.h"
+#include "cpu-qom.h"
 
 #define PCALIGN 4
 #define PCALIGN_MASK (PCALIGN - 1)
@@ -65,6 +66,7 @@ static inline bool is_packet_end(uint32_t endocing)
     return ((bits == 0x3) || (bits == 0x0));
 }
 
-int disassemble_hexagon(uint32_t *words, int nwords, bfd_vma pc, GString *buf);
+int disassemble_hexagon(uint32_t *words, int nwords, bfd_vma pc, GString *buf,
+                        const HexagonCPUDef *hex_def);
 
 #endif

target/hexagon/decode.c

@@ -828,19 +828,36 @@ int decode_packet(DisasContext *ctx, int max_words, const uint32_t *words,
 
 /* Used for "-d in_asm" logging */
 int disassemble_hexagon(uint32_t *words, int nwords, bfd_vma pc,
-                        GString *buf)
+                        GString *buf, const HexagonCPUDef  *hex_def)
 {
+    HexagonCPUDef any_def = {
+        .hex_version = HEX_VER_ANY,  /* Allow decode to accept anything */
+    };
     DisasContext ctx;
     Packet pkt;
 
     memset(&ctx, 0, sizeof(DisasContext));
+    ctx.hex_def = &any_def;
     ctx.pkt = &pkt;
 
     if (decode_packet(&ctx, nwords, words, &pkt, true) > 0) {
-        snprint_a_pkt_disas(buf, &pkt, words, pc);
+        snprint_a_pkt_disas(buf, &pkt, words, pc, hex_def);
         return pkt.encod_pkt_size_in_bytes;
     } else {
-        g_string_assign(buf, "<invalid>");
-        return 0;
+        for (int i = 0; i < nwords; i++) {
+            g_string_append_printf(buf, "0x" TARGET_FMT_lx "\t", words[i]);
+            if (i == 0) {
+                g_string_append(buf, "{");
+            }
+            g_string_append(buf, "\t");
+            g_string_append(buf, "<invalid>");
+            if (i < nwords - 1) {
+                pc += 4;
+                g_string_append_printf(buf, "\n0x" TARGET_FMT_lx ":  ",
+                                       (target_ulong)pc);
+            }
+        }
+        g_string_append(buf, " }");
+        return nwords * sizeof(uint32_t);
     }
 }

target/hexagon/printinsn.c

@@ -21,6 +21,7 @@
 #include "insn.h"
 #include "reg_fields.h"
 #include "internal.h"
+#include "decode.h"
 
 static const char *sreg2str(unsigned int reg)
 {
@@ -51,7 +52,7 @@ static void snprintinsn(GString *buf, Insn *insn)
 }
 
 void snprint_a_pkt_disas(GString *buf, Packet *pkt, uint32_t *words,
-                         target_ulong pc)
+                         target_ulong pc, const HexagonCPUDef *hex_def)
 {
     bool has_endloop0 = false;
     bool has_endloop1 = false;
@@ -83,7 +84,11 @@ void snprint_a_pkt_disas(GString *buf, Packet *pkt, uint32_t *words,
         }
 
         g_string_append(buf, "\t");
-        snprintinsn(buf, &(pkt->insn[i]));
+        if (opcode_supported(pkt->insn[i].opcode, hex_def)) {
+            snprintinsn(buf, &(pkt->insn[i]));
+        } else {
+            g_string_append(buf, "<invalid>");
+        }
 
         if (i < pkt->num_insns - 1) {
             /*

target/hexagon/printinsn.h

@@ -18,10 +18,11 @@
 #ifndef HEXAGON_PRINTINSN_H
 #define HEXAGON_PRINTINSN_H
 
+#include "cpu-qom.h"
 #include "insn.h"
 
 void snprint_a_pkt_disas(GString *buf, Packet *pkt, uint32_t *words,
-                         target_ulong pc);
+                         target_ulong pc, const HexagonCPUDef *hex_def);
 void snprint_a_pkt_debug(GString *buf, Packet *pkt);
 
 #endif