tpm: report backend request error

Use an Error** for request to let the caller handle error reporting.

This will also allow to inform the frontend of a backend error.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

backends/tpm.c

@@ -27,7 +27,7 @@ static void tpm_backend_request_completed(void *opaque, int ret)
     TPMBackend *s = TPM_BACKEND(opaque);
     TPMIfClass *tic = TPM_IF_GET_CLASS(s->tpmif);
 
-    tic->request_completed(s->tpmif);
+    tic->request_completed(s->tpmif, ret);
 
     /* no need for atomic, as long the BQL is taken */
     s->cmd = NULL;
@@ -38,8 +38,13 @@ static int tpm_backend_worker_thread(gpointer data)
 {
     TPMBackend *s = TPM_BACKEND(data);
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
+    Error *err = NULL;
 
-    k->handle_request(s, s->cmd);
+    k->handle_request(s, s->cmd, &err);
+    if (err) {
+        error_report_err(err);
+        return -1;
+    }
 
     return 0;
 }

hw/tpm/tpm_emulator.c

@@ -183,28 +183,19 @@ static int tpm_emulator_set_locality(TPMEmulator *tpm_emu, uint8_t locty_number,
     return 0;
 }
 
-static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd)
+static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd,
+                                        Error **errp)
 {
     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
-    Error *err = NULL;
 
     DPRINTF("processing TPM command");
 
-    if (tpm_emulator_set_locality(tpm_emu, cmd->locty, &err) < 0) {
+    if (tpm_emulator_set_locality(tpm_emu, cmd->locty, errp) < 0 ||
-        goto error;
+        tpm_emulator_unix_tx_bufs(tpm_emu, cmd->in, cmd->in_len,
-    }
-
-    if (tpm_emulator_unix_tx_bufs(tpm_emu, cmd->in, cmd->in_len,
                                   cmd->out, cmd->out_len,
-                                  &cmd->selftest_done, &err) < 0) {
+                                  &cmd->selftest_done, errp) < 0) {
-        goto error;
-    }
-
-    return;
-
-error:
         tpm_util_write_fatal_error_response(cmd->out, cmd->out_len);
-    error_report_err(err);
+    }
 }
 
 static int tpm_emulator_probe_caps(TPMEmulator *tpm_emu)

hw/tpm/tpm_passthrough.c

@@ -80,10 +80,11 @@ static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
     }
     return ret;
 }
-static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
+
+static void tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
                                          const uint8_t *in, uint32_t in_len,
                                          uint8_t *out, uint32_t out_len,
-                                        bool *selftest_done)
+                                         bool *selftest_done, Error **errp)
 {
     ssize_t ret;
     bool is_selftest;
@@ -98,9 +99,8 @@ static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
     ret = qemu_write_full(tpm_pt->tpm_fd, in, in_len);
     if (ret != in_len) {
         if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
-            error_report("tpm_passthrough: error while transmitting data "
+            error_setg_errno(errp, errno, "tpm_passthrough: error while "
-                         "to TPM: %s (%i)",
+                             "transmitting data to TPM");
-                         strerror(errno), errno);
         }
         goto err_exit;
     }
@@ -110,15 +110,14 @@ static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
     ret = tpm_passthrough_unix_read(tpm_pt->tpm_fd, out, out_len);
     if (ret < 0) {
         if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
-            error_report("tpm_passthrough: error while reading data from "
+            error_setg_errno(errp, errno, "tpm_passthrough: error while "
-                         "TPM: %s (%i)",
+                             "reading data from TPM");
-                         strerror(errno), errno);
         }
     } else if (ret < sizeof(struct tpm_resp_hdr) ||
                tpm_cmd_get_size(out) != ret) {
         ret = -1;
-        error_report("tpm_passthrough: received invalid response "
+        error_setg_errno(errp, errno, "tpm_passthrough: received invalid "
-                     "packet from TPM");
+                     "response packet from TPM");
     }
 
     if (is_selftest && (ret >= sizeof(struct tpm_resp_hdr))) {
@@ -131,18 +130,18 @@ err_exit:
     }
 
     tpm_pt->tpm_executing = false;
-
-    return ret;
 }
 
-static void tpm_passthrough_handle_request(TPMBackend *tb, TPMBackendCmd *cmd)
+static void tpm_passthrough_handle_request(TPMBackend *tb, TPMBackendCmd *cmd,
+                                           Error **errp)
 {
     TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
 
     DPRINTF("tpm_passthrough: processing command %p\n", cmd);
 
     tpm_passthrough_unix_tx_bufs(tpm_pt, cmd->in, cmd->in_len,
-                                 cmd->out, cmd->out_len, &cmd->selftest_done);
+                                 cmd->out, cmd->out_len, &cmd->selftest_done,
+                                 errp);
 }
 
 static void tpm_passthrough_reset(TPMBackend *tb)

hw/tpm/tpm_tis.c

@@ -393,7 +393,7 @@ static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
 /*
  * Callback from the TPM to indicate that the response was received.
  */
-static void tpm_tis_request_completed(TPMIf *ti)
+static void tpm_tis_request_completed(TPMIf *ti, int ret)
 {
     TPMState *s = TPM(ti);
     uint8_t locty = s->cmd.locty;
@@ -405,6 +405,7 @@ static void tpm_tis_request_completed(TPMIf *ti)
         }
     }
 
+    /* FIXME: report error if ret != 0 */
     tpm_tis_sts_set(&s->loc[locty],
                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;

include/sysemu/tpm.h

@@ -41,7 +41,7 @@ typedef struct TPMIfClass {
     InterfaceClass parent_class;
 
     enum TpmModel model;
-    void (*request_completed)(TPMIf *obj);
+    void (*request_completed)(TPMIf *obj, int ret);
     enum TPMVersion (*get_version)(TPMIf *obj);
 } TPMIfClass;
 

include/sysemu/tpm_backend.h

@@ -18,6 +18,7 @@
 #include "qapi-types.h"
 #include "qemu/option.h"
 #include "sysemu/tpm.h"
+#include "qapi/error.h"
 
 #define TYPE_TPM_BACKEND "tpm-backend"
 #define TPM_BACKEND(obj) \
@@ -84,7 +85,7 @@ struct TPMBackendClass {
 
     TpmTypeOptions *(*get_tpm_options)(TPMBackend *t);
 
-    void (*handle_request)(TPMBackend *s, TPMBackendCmd *cmd);
+    void (*handle_request)(TPMBackend *s, TPMBackendCmd *cmd, Error **errp);
 };
 
 /**