i386/tdx: Wire TDX_REPORT_FATAL_ERROR with GuestPanic facility

Integrate TDX's TDX_REPORT_FATAL_ERROR into QEMU GuestPanic facility

Originated-from: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-30-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/system/runstate.c b/system/runstate.c
index de74d962bc..38900c935a 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -590,6 +590,58 @@ static void qemu_system_wakeup(void)
     }
 }
 
+static char *tdx_parse_panic_message(char *message)
+{
+    bool printable = false;
+    char *buf = NULL;
+    int len = 0, i;
+
+    /*
+     * Although message is defined as a json string, we shouldn't
+     * unconditionally treat it as is because the guest generated it and
+     * it's not necessarily trustable.
+     */
+    if (message) {
+        /* The caller guarantees the NULL-terminated string. */
+        len = strlen(message);
+
+        printable = len > 0;
+        for (i = 0; i < len; i++) {
+            if (!(0x20 <= message[i] && message[i] <= 0x7e)) {
+                printable = false;
+                break;
+            }
+        }
+    }
+
+    if (len == 0) {
+        buf = g_malloc(1);
+        buf[0] = '\0';
+    } else {
+        if (!printable) {
+            /* 3 = length of "%02x " */
+            buf = g_malloc(len * 3);
+            for (i = 0; i < len; i++) {
+                if (message[i] == '\0') {
+                    break;
+                } else {
+                    sprintf(buf + 3 * i, "%02x ", message[i]);
+                }
+            }
+            if (i > 0) {
+                /* replace the last ' '(space) to NULL */
+                buf[i * 3 - 1] = '\0';
+            } else {
+                buf[0] = '\0';
+            }
+        } else {
+            buf = g_strdup(message);
+        }
+    }
+
+    return buf;
+}
+
 void qemu_system_guest_panicked(GuestPanicInformation *info)
 {
     qemu_log_mask(LOG_GUEST_ERROR, "Guest crashed");
@@ -631,7 +683,20 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
                           S390CrashReason_str(info->u.s390.reason),
                           info->u.s390.psw_mask,
                           info->u.s390.psw_addr);
+        } else if (info->type == GUEST_PANIC_INFORMATION_TYPE_TDX) {
+            char *message = tdx_parse_panic_message(info->u.tdx.message);
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "\nTDX guest reports fatal error."
+                          " error code: 0x%" PRIx32 " error message:\"%s\"\n",
+                          info->u.tdx.error_code, message);
+            g_free(message);
+            if (info->u.tdx.gpa != -1ull) {
+                qemu_log_mask(LOG_GUEST_ERROR, "Additional error information "
+                              "can be found at gpa page: 0x%" PRIx64 "\n",
+                              info->u.tdx.gpa);
+            }
         }
+
         qapi_free_GuestPanicInformation(info);
     }
 }