[PATCH 23/25] contrib/plugins/uftrace: implement x64 support

["Alex Bennée" <alex.bennee@linaro.org>]

From: Pierrick Bouvier <pierrick.bouvier@linaro.org>

It's trivial to implement x64 support, as it's the same stack layout
as aarch64.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20250902075042.223990-8-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 contrib/plugins/uftrace.c | 86 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/contrib/plugins/uftrace.c b/contrib/plugins/uftrace.c
index 2386cc723bc..b7d6124d2f5 100644
--- a/contrib/plugins/uftrace.c
+++ b/contrib/plugins/uftrace.c
@@ -82,6 +82,21 @@ typedef struct {
     struct qemu_plugin_register *reg_scr_el3;
 } Aarch64Cpu;
 
+typedef enum {
+    X64_RING0,
+    X64_RING1,
+    X64_RING2,
+    X64_RING3,
+    X64_REAL_MODE,
+    X64_PRIVILEGE_LEVEL_MAX,
+} X64PrivilegeLevel;
+
+typedef struct {
+    struct qemu_plugin_register *reg_rbp;
+    struct qemu_plugin_register *reg_cs;
+    struct qemu_plugin_register *reg_cr0;
+} X64Cpu;
+
 typedef struct {
     uint64_t timestamp;
     uint64_t data;
@@ -570,6 +585,75 @@ static CpuOps aarch64_ops = {
     .does_insn_modify_frame_pointer = aarch64_does_insn_modify_frame_pointer,
 };
 
+static uint8_t x64_num_privilege_levels(void)
+{
+    return X64_PRIVILEGE_LEVEL_MAX;
+}
+
+static const char *x64_get_privilege_level_name(uint8_t pl)
+{
+    switch (pl) {
+    case X64_RING0: return "Ring0";
+    case X64_RING1: return "Ring1";
+    case X64_RING2: return "Ring2";
+    case X64_RING3: return "Ring3";
+    case X64_REAL_MODE: return "RealMode";
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static uint8_t x64_get_privilege_level(Cpu *cpu_)
+{
+    X64Cpu *cpu = cpu_->arch;
+    uint64_t cr0 = cpu_read_register64(cpu_, cpu->reg_cr0);
+    uint64_t protected_mode = (cr0 >> 0) & 0b1;
+    if (!protected_mode) {
+        return X64_REAL_MODE;
+    }
+    uint32_t cs = cpu_read_register32(cpu_, cpu->reg_cs);
+    uint32_t ring_level = (cs >> 0) & 0b11;
+    return ring_level;
+}
+
+static uint64_t x64_get_frame_pointer(Cpu *cpu_)
+{
+    X64Cpu *cpu = cpu_->arch;
+    return cpu_read_register64(cpu_, cpu->reg_rbp);
+}
+
+static void x64_init(Cpu *cpu_)
+{
+    X64Cpu *cpu = g_new0(X64Cpu, 1);
+    cpu_->arch = cpu;
+    cpu->reg_rbp = plugin_find_register("rbp");
+    g_assert(cpu->reg_rbp);
+    cpu->reg_cs = plugin_find_register("cs");
+    g_assert(cpu->reg_cs);
+    cpu->reg_cr0 = plugin_find_register("cr0");
+    g_assert(cpu->reg_cr0);
+}
+
+static void x64_end(Cpu *cpu)
+{
+    g_free(cpu->arch);
+}
+
+static bool x64_does_insn_modify_frame_pointer(const char *disas)
+{
+    return strstr(disas, "rbp");
+}
+
+static CpuOps x64_ops = {
+    .init = x64_init,
+    .end = x64_end,
+    .get_frame_pointer = x64_get_frame_pointer,
+    .get_privilege_level = x64_get_privilege_level,
+    .num_privilege_levels = x64_num_privilege_levels,
+    .get_privilege_level_name = x64_get_privilege_level_name,
+    .does_insn_modify_frame_pointer = x64_does_insn_modify_frame_pointer,
+};
+
 static void track_privilege_change(unsigned int cpu_index, void *udata)
 {
     Cpu *cpu = qemu_plugin_scoreboard_find(score, cpu_index);
@@ -777,6 +861,8 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 
     if (!strcmp(info->target_name, "aarch64")) {
         arch_ops = aarch64_ops;
+    } else if (!strcmp(info->target_name, "x86_64")) {
+        arch_ops = x64_ops;
     } else {
         fprintf(stderr, "plugin uftrace: %s target is not supported\n",
                 info->target_name);
-- 
2.47.3