From 7885b8558a6f1f11465a62021d96b0fd45ab6452 Mon Sep 17 00:00:00 2001
From: Denis Drakhnia <numas13@gmail.com>
Date: Wed, 6 Dec 2023 19:07:21 +0200
Subject: [PATCH] e2k: add gdb_rw_tags

---
 gdbstub/gdbstub.c     | 46 +++++++++++++++++++++++++++++++++++++++++++
 include/hw/core/cpu.h |  2 ++
 target/e2k/cpu.c      |  1 +
 target/e2k/cpu.h      |  2 ++
 target/e2k/gdbstub.c  | 34 ++++++++++++++++++++++++++++++++
 5 files changed, 85 insertions(+)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 9c23d44baf..d0671d95b6 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1681,6 +1681,12 @@ static void handle_query_supported(GArray *params, void *user_ctx)
 #endif
     }
 
+    if (cc->gdb_rw_tags) {
+        g_string_append(gdbserver_state.str_buf, ";qXfer:tags:read+");
+        // TODO: g_string_append(gdbserver_state.str_buf, ";qXfer:tags:write+");
+        // TODO: g_string_append(gdbserver_state.str_buf, ";qXfer:packed_tags:read+");
+    }
+
     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
     gdb_put_strbuf();
 }
@@ -1745,6 +1751,40 @@ static void handle_query_qemu_supported(GArray *params, void *user_ctx)
     gdb_put_strbuf();
 }
 
+static void handle_query_tags_read(GArray *params, void *user_ctx)
+{
+    CPUClass *cc;
+    unsigned long long addr;
+    unsigned long len;
+    uint8_t buf[256];
+
+    if (params->len < 2) {
+        gdb_put_packet("E22");
+        return;
+    }
+
+    addr = get_param(params, 0)->val_ull;
+    len = get_param(params, 1)->val_ul;
+    cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
+
+    g_string_assign(gdbserver_state.str_buf, "l");
+    while (len) {
+        unsigned long l = MIN(len, sizeof(buf));
+
+        cc->gdb_rw_tags(gdbserver_state.g_cpu, addr, buf, l, false);
+
+        for (int i = 0; i < l; i++) {
+            g_string_append_c(gdbserver_state.str_buf, buf[i]);
+        }
+
+        addr += l;
+        len -= l;
+    }
+
+    gdb_put_packet_binary(gdbserver_state.str_buf->str,
+        gdbserver_state.str_buf->len, true);
+}
+
 static const GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
     /* Order is important if has same prefix */
     {
@@ -1853,6 +1893,12 @@ static const GdbCmdParseEntry gdb_gen_query_table[] = {
         .cmd = "qemu.PhyMemMode",
     },
 #endif
+    {
+        .handler = handle_query_tags_read,
+        .cmd = "Xfer:tags:read::",
+        .cmd_startswith = 1,
+        .schema = "L,l0",
+    },
 };
 
 static const GdbCmdParseEntry gdb_gen_set_table[] = {
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index ec14f74ce5..5ade9ab1d6 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -159,6 +159,8 @@ struct CPUClass {
     vaddr (*get_pc)(CPUState *cpu);
     int (*gdb_read_register)(CPUState *cpu, GByteArray *buf, int reg);
     int (*gdb_write_register)(CPUState *cpu, uint8_t *buf, int reg);
+    void (*gdb_rw_tags)(CPUState *cpu, vaddr addr,
+                        uint8_t *buf, int len, bool is_write);
     vaddr (*gdb_adjust_breakpoint)(CPUState *cpu, vaddr addr);
 
     const char *gdb_core_xml_file;
diff --git a/target/e2k/cpu.c b/target/e2k/cpu.c
index 3b0ff4d52b..0e2d4d9e22 100644
--- a/target/e2k/cpu.c
+++ b/target/e2k/cpu.c
@@ -281,6 +281,7 @@ static void e2k_cpu_class_init(ObjectClass *oc, void *data)
     cc->gdb_arch_name      = e2k_cpu_gdb_arch_name;
     cc->gdb_read_register  = e2k_cpu_gdb_read_register;
     cc->gdb_write_register = e2k_cpu_gdb_write_register;
+    cc->gdb_rw_tags        = e2k_cpu_gdb_rw_tags;
     cc->gdb_num_core_regs  = 574;
 
     cc->tcg_ops = &e2k_tcg_ops;
diff --git a/target/e2k/cpu.h b/target/e2k/cpu.h
index e8b2917405..db0af7a878 100644
--- a/target/e2k/cpu.h
+++ b/target/e2k/cpu.h
@@ -939,6 +939,8 @@ void e2k_cpu_list(void);
 int e2k_cpu_signal_handler(int host_signum, void *pinfo, void *puc);
 int e2k_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n);
 int e2k_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n);
+void e2k_cpu_gdb_rw_tags(CPUState *cpu, vaddr addr,
+                         uint8_t *buf, int len, bool is_write);
 void e2k_cpu_register_gdb_regs_for_features(CPUState *cs);
 bool e2k_cpu_tlb_fill(CPUState *cpu, vaddr address, int size,
                  MMUAccessType access_type, int mmu_idx,
diff --git a/target/e2k/gdbstub.c b/target/e2k/gdbstub.c
index 11b82ccd11..ba5e69cf37 100644
--- a/target/e2k/gdbstub.c
+++ b/target/e2k/gdbstub.c
@@ -384,3 +384,37 @@ void e2k_cpu_register_gdb_regs_for_features(CPUState *cs)
                                  gdb_find_static_feature("e2k-v5.xml"), 576);
     }
 }
+
+void e2k_cpu_gdb_rw_tags(CPUState *cs, vaddr addr,
+                         uint8_t *buf, int len, bool is_write)
+{
+    E2KCPU *cpu = E2K_CPU(cs);
+    CPUE2KState *env = &cpu->env;
+
+    if (is_write) {
+        // TODO: e2k write tags
+        return;
+    }
+
+#ifdef CONFIG_USER_ONLY
+    if (env->psp.base <= addr && addr < (env->psp.base + env->psp.size)) {
+        target_ulong offset = addr - env->psp.base;
+        target_ulong ptr = env->psp.base_tag + offset / 8;
+
+        for (int i = 0; i < len; i += 4, ptr++) {
+            uint8_t tags;
+
+            cpu_memory_rw_debug(cs, ptr, &tags, sizeof(tags), false);
+
+            for (int j = 0; j < 4 && (i + j) < len; j++) {
+                buf[i + j] = (tags >> (j * 2)) & 3;
+            }
+        }
+    } else {
+        memset(buf, 0, len);
+    }
+#else
+    // TODO: e2k-softmmu read tags
+    memset(buf, 0, len);
+#endif
+}