[PATCH for-5.1 0/2] tpm: Fix error reporting, improve help

[PATCH for-5.1 0/2] tpm: Fix error reporting, improve help

[Markus Armbruster]

The alternative to PATCH 1 is a proper conversion to Error, as
discussed in

    Subject: Re: What is TYPE_TPM_TIS_ISA? (Not an ISA Device)
    Message-ID: <87tuxyoauy.fsf@dusky.pond.sub.org>

Such a conversion would be much too invasive for 5.1.  Going the other
way, like PATCH 1 does, is simple enough to be considered for 5.1.

To make this series a complete alternative to Philippe's
"[PATCH-for-5.1 v2 0/2] tpm: Improve error reporting", PATCH 2
improves help.

Markus Armbruster (2):
  Revert "tpm: Clean up error reporting in tpm_init_tpmdev()"
  tpm: Improve help on TPM types when none are available

 include/sysemu/tpm.h |  2 +-
 softmmu/vl.c         |  4 +++-
 stubs/tpm.c          |  3 ++-
 tpm.c                | 43 ++++++++++++++++++++++++++++++-------------
 4 files changed, 36 insertions(+), 16 deletions(-)

-- 
2.26.2

[PATCH for-5.1 1/2] Revert "tpm: Clean up error reporting in tpm_init_tpmdev()"

[Markus Armbruster]

This reverts commit d10e05f15d5c3dd5e5cc59c5dfff460d89d48580.

We report some -tpmdev failures, but then continue as if all was fine.
Reproducer:

    $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio -chardev null,id=tpm0 -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
    qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: tpm chardev 'chrtpm' not found.
    qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: Could not cleanly shutdown the TPM: No such file or directory
    QEMU 5.0.90 monitor - type 'help' for more information
    (qemu) qemu-system-x86_64: -device tpm-tis,tpmdev=tpm0: Property 'tpm-tis.tpmdev' can't find value 'tpm0'
    $ echo $?
    1

This is a regression caused by commit d10e05f15d "tpm: Clean up error
reporting in tpm_init_tpmdev()".  It's incomplete: be->create(opts)
continues to use error_report(), and we don't set an error when it
fails.

I figure converting the create() methods to Error would make some
sense, but I'm not sure it's worth the effort right now.  Revert the
broken commit instead, and add a comment to tpm_init_tpmdev().

Straightforward conflict in tpm.c resolved.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 include/sysemu/tpm.h |  2 +-
 softmmu/vl.c         |  4 +++-
 stubs/tpm.c          |  3 ++-
 tpm.c                | 30 +++++++++++++++++++++---------
 4 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
index 03fb25941c..730c61ac97 100644
--- a/include/sysemu/tpm.h
+++ b/include/sysemu/tpm.h
@@ -16,7 +16,7 @@
 #include "qom/object.h"
 
 int tpm_config_parse(QemuOptsList *opts_list, const char *optarg);
-void tpm_init(void);
+int tpm_init(void);
 void tpm_cleanup(void);
 
 typedef enum TPMVersion {
diff --git a/softmmu/vl.c b/softmmu/vl.c
index f476ef89ed..2c06cf0513 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -4262,7 +4262,9 @@ void qemu_init(int argc, char **argv, char **envp)
                       user_creatable_add_opts_foreach,
                       object_create_delayed, &error_fatal);
 
-    tpm_init();
+    if (tpm_init() < 0) {
+        exit(1);
+    }
 
     blk_mig_init();
     ram_mig_init();
diff --git a/stubs/tpm.c b/stubs/tpm.c
index 66c99d667d..9bded191d9 100644
--- a/stubs/tpm.c
+++ b/stubs/tpm.c
@@ -10,8 +10,9 @@
 #include "sysemu/tpm.h"
 #include "hw/acpi/tpm.h"
 
-void tpm_init(void)
+int tpm_init(void)
 {
+    return 0;
 }
 
 void tpm_cleanup(void)
diff --git a/tpm.c b/tpm.c
index fe03b24858..f6045bb6da 100644
--- a/tpm.c
+++ b/tpm.c
@@ -81,26 +81,33 @@ TPMBackend *qemu_find_tpm_be(const char *id)
 
 static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
 {
+    /*
+     * Use of error_report() in a function with an Error ** parameter
+     * is suspicious.  It is okay here.  The parameter only exists to
+     * make the function usable with qemu_opts_foreach().  It is not
+     * actually used.
+     */
     const char *value;
     const char *id;
     const TPMBackendClass *be;
     TPMBackend *drv;
+    Error *local_err = NULL;
     int i;
 
     if (!QLIST_EMPTY(&tpm_backends)) {
-        error_setg(errp, "Only one TPM is allowed.");
+        error_report("Only one TPM is allowed.");
         return 1;
     }
 
     id = qemu_opts_id(opts);
     if (id == NULL) {
-        error_setg(errp, QERR_MISSING_PARAMETER, "id");
+        error_report(QERR_MISSING_PARAMETER, "id");
         return 1;
     }
 
     value = qemu_opt_get(opts, "type");
     if (!value) {
-        error_setg(errp, QERR_MISSING_PARAMETER, "type");
+        error_report(QERR_MISSING_PARAMETER, "type");
         tpm_display_backend_drivers();
         return 1;
     }
@@ -108,14 +115,15 @@ static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
     i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
     be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
     if (be == NULL) {
-        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
-                   "a TPM backend type");
+        error_report(QERR_INVALID_PARAMETER_VALUE,
+                     "type", "a TPM backend type");
         tpm_display_backend_drivers();
         return 1;
     }
 
     /* validate backend specific opts */
-    if (!qemu_opts_validate(opts, be->opts, errp)) {
+    if (!qemu_opts_validate(opts, be->opts, &local_err)) {
+        error_report_err(local_err);
         return 1;
     }
 
@@ -148,10 +156,14 @@ void tpm_cleanup(void)
  * Initialize the TPM. Process the tpmdev command line options describing the
  * TPM backend.
  */
-void tpm_init(void)
+int tpm_init(void)
 {
-    qemu_opts_foreach(qemu_find_opts("tpmdev"),
-                      tpm_init_tpmdev, NULL, &error_fatal);
+    if (qemu_opts_foreach(qemu_find_opts("tpmdev"),
+                          tpm_init_tpmdev, NULL, NULL)) {
+        return -1;
+    }
+
+    return 0;
 }
 
 /*
-- 
2.26.2

Re: [PATCH for-5.1 1/2] Revert "tpm: Clean up error reporting in tpm_init_tpmdev()"

[Philippe Mathieu-Daudé]

On 7/23/20 1:58 PM, Markus Armbruster wrote:
> This reverts commit d10e05f15d5c3dd5e5cc59c5dfff460d89d48580.
> 
> We report some -tpmdev failures, but then continue as if all was fine.
> Reproducer:
> 
>     $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio -chardev null,id=tpm0 -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
>     qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: tpm chardev 'chrtpm' not found.
>     qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: Could not cleanly shutdown the TPM: No such file or directory
>     QEMU 5.0.90 monitor - type 'help' for more information
>     (qemu) qemu-system-x86_64: -device tpm-tis,tpmdev=tpm0: Property 'tpm-tis.tpmdev' can't find value 'tpm0'
>     $ echo $?
>     1
> 
> This is a regression caused by commit d10e05f15d "tpm: Clean up error
> reporting in tpm_init_tpmdev()".  It's incomplete: be->create(opts)
> continues to use error_report(), and we don't set an error when it
> fails.
> 
> I figure converting the create() methods to Error would make some
> sense, but I'm not sure it's worth the effort right now.  Revert the
> broken commit instead, and add a comment to tpm_init_tpmdev().
> 
> Straightforward conflict in tpm.c resolved.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  include/sysemu/tpm.h |  2 +-
>  softmmu/vl.c         |  4 +++-
>  stubs/tpm.c          |  3 ++-
>  tpm.c                | 30 +++++++++++++++++++++---------
>  4 files changed, 27 insertions(+), 12 deletions(-)
> 
> diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
> index 03fb25941c..730c61ac97 100644
> --- a/include/sysemu/tpm.h
> +++ b/include/sysemu/tpm.h
> @@ -16,7 +16,7 @@
>  #include "qom/object.h"
>  
>  int tpm_config_parse(QemuOptsList *opts_list, const char *optarg);
> -void tpm_init(void);
> +int tpm_init(void);
>  void tpm_cleanup(void);
>  
>  typedef enum TPMVersion {
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index f476ef89ed..2c06cf0513 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -4262,7 +4262,9 @@ void qemu_init(int argc, char **argv, char **envp)
>                        user_creatable_add_opts_foreach,
>                        object_create_delayed, &error_fatal);
>  
> -    tpm_init();
> +    if (tpm_init() < 0) {
> +        exit(1);
> +    }
>  
>      blk_mig_init();
>      ram_mig_init();
> diff --git a/stubs/tpm.c b/stubs/tpm.c
> index 66c99d667d..9bded191d9 100644
> --- a/stubs/tpm.c
> +++ b/stubs/tpm.c
> @@ -10,8 +10,9 @@
>  #include "sysemu/tpm.h"
>  #include "hw/acpi/tpm.h"
>  
> -void tpm_init(void)
> +int tpm_init(void)
>  {
> +    return 0;
>  }
>  
>  void tpm_cleanup(void)
> diff --git a/tpm.c b/tpm.c
> index fe03b24858..f6045bb6da 100644
> --- a/tpm.c
> +++ b/tpm.c
> @@ -81,26 +81,33 @@ TPMBackend *qemu_find_tpm_be(const char *id)
>  
>  static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
>  {
> +    /*
> +     * Use of error_report() in a function with an Error ** parameter
> +     * is suspicious.  It is okay here.  The parameter only exists to
> +     * make the function usable with qemu_opts_foreach().  It is not
> +     * actually used.
> +     */
>      const char *value;
>      const char *id;
>      const TPMBackendClass *be;
>      TPMBackend *drv;
> +    Error *local_err = NULL;
>      int i;
>  
>      if (!QLIST_EMPTY(&tpm_backends)) {
> -        error_setg(errp, "Only one TPM is allowed.");
> +        error_report("Only one TPM is allowed.");
>          return 1;
>      }
>  
>      id = qemu_opts_id(opts);
>      if (id == NULL) {
> -        error_setg(errp, QERR_MISSING_PARAMETER, "id");
> +        error_report(QERR_MISSING_PARAMETER, "id");
>          return 1;
>      }
>  
>      value = qemu_opt_get(opts, "type");
>      if (!value) {
> -        error_setg(errp, QERR_MISSING_PARAMETER, "type");
> +        error_report(QERR_MISSING_PARAMETER, "type");
>          tpm_display_backend_drivers();
>          return 1;
>      }
> @@ -108,14 +115,15 @@ static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
>      i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
>      be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
>      if (be == NULL) {
> -        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
> -                   "a TPM backend type");
> +        error_report(QERR_INVALID_PARAMETER_VALUE,
> +                     "type", "a TPM backend type");
>          tpm_display_backend_drivers();
>          return 1;
>      }
>  
>      /* validate backend specific opts */
> -    if (!qemu_opts_validate(opts, be->opts, errp)) {
> +    if (!qemu_opts_validate(opts, be->opts, &local_err)) {
> +        error_report_err(local_err);
>          return 1;
>      }
>  
> @@ -148,10 +156,14 @@ void tpm_cleanup(void)
>   * Initialize the TPM. Process the tpmdev command line options describing the
>   * TPM backend.
>   */
> -void tpm_init(void)
> +int tpm_init(void)
>  {
> -    qemu_opts_foreach(qemu_find_opts("tpmdev"),
> -                      tpm_init_tpmdev, NULL, &error_fatal);
> +    if (qemu_opts_foreach(qemu_find_opts("tpmdev"),
> +                          tpm_init_tpmdev, NULL, NULL)) {
> +        return -1;
> +    }
> +
> +    return 0;
>  }
>  
>  /*
> 

Re: [PATCH for-5.1 1/2] Revert "tpm: Clean up error reporting in tpm_init_tpmdev()"

[Stefan Berger]

On 7/23/20 8:50 AM, Philippe Mathieu-Daudé wrote:
> On 7/23/20 1:58 PM, Markus Armbruster wrote:
>> This reverts commit d10e05f15d5c3dd5e5cc59c5dfff460d89d48580.
>>
>> We report some -tpmdev failures, but then continue as if all was fine.
>> Reproducer:
>>
>>      $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio -chardev null,id=tpm0 -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
>>      qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: tpm chardev 'chrtpm' not found.
>>      qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: tpm-emulator: Could not cleanly shutdown the TPM: No such file or directory
>>      QEMU 5.0.90 monitor - type 'help' for more information
>>      (qemu) qemu-system-x86_64: -device tpm-tis,tpmdev=tpm0: Property 'tpm-tis.tpmdev' can't find value 'tpm0'
>>      $ echo $?
>>      1
>>
>> This is a regression caused by commit d10e05f15d "tpm: Clean up error
>> reporting in tpm_init_tpmdev()".  It's incomplete: be->create(opts)
>> continues to use error_report(), and we don't set an error when it
>> fails.
>>
>> I figure converting the create() methods to Error would make some
>> sense, but I'm not sure it's worth the effort right now.  Revert the
>> broken commit instead, and add a comment to tpm_init_tpmdev().
>>
>> Straightforward conflict in tpm.c resolved.
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>


Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>

[PATCH for-5.1 2/2] tpm: Improve help on TPM types when none are available

[Markus Armbruster]

Help is a bit awkward when no TPM types are built into QEMU:

    $ upstream-qemu -tpmdev nonexistent,id=tpm0
    upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
    Supported TPM types (choose only one):

Improve to

    upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
    No TPM backend types are available

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 tpm.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tpm.c b/tpm.c
index f6045bb6da..cab206355a 100644
--- a/tpm.c
+++ b/tpm.c
@@ -47,18 +47,23 @@ tpm_be_find_by_type(enum TpmType type)
  */
 static void tpm_display_backend_drivers(void)
 {
+    bool got_one = false;
     int i;
 
-    fprintf(stderr, "Supported TPM types (choose only one):\n");
-
     for (i = 0; i < TPM_TYPE__MAX; i++) {
         const TPMBackendClass *bc = tpm_be_find_by_type(i);
         if (!bc) {
             continue;
         }
-        fprintf(stderr, "%12s   %s\n", TpmType_str(i), bc->desc);
+        if (!got_one) {
+            error_printf("Supported TPM types (choose only one):\n");
+            got_one = true;
+        }
+        error_printf("%12s   %s\n", TpmType_str(i), bc->desc);
+    }
+    if (!got_one) {
+        error_printf("No TPM backend types are available\n");
     }
-    fprintf(stderr, "\n");
 }
 
 /*
-- 
2.26.2

Re: [PATCH for-5.1 2/2] tpm: Improve help on TPM types when none are available

[Philippe Mathieu-Daudé]

On 7/23/20 1:58 PM, Markus Armbruster wrote:
> Help is a bit awkward when no TPM types are built into QEMU:
> 
>     $ upstream-qemu -tpmdev nonexistent,id=tpm0
>     upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>     Supported TPM types (choose only one):
> 
> Improve to
> 
>     upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>     No TPM backend types are available
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  tpm.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/tpm.c b/tpm.c
> index f6045bb6da..cab206355a 100644
> --- a/tpm.c
> +++ b/tpm.c
> @@ -47,18 +47,23 @@ tpm_be_find_by_type(enum TpmType type)
>   */
>  static void tpm_display_backend_drivers(void)
>  {
> +    bool got_one = false;
>      int i;
>  
> -    fprintf(stderr, "Supported TPM types (choose only one):\n");
> -
>      for (i = 0; i < TPM_TYPE__MAX; i++) {
>          const TPMBackendClass *bc = tpm_be_find_by_type(i);
>          if (!bc) {
>              continue;
>          }
> -        fprintf(stderr, "%12s   %s\n", TpmType_str(i), bc->desc);
> +        if (!got_one) {
> +            error_printf("Supported TPM types (choose only one):\n");
> +            got_one = true;
> +        }
> +        error_printf("%12s   %s\n", TpmType_str(i), bc->desc);
> +    }
> +    if (!got_one) {
> +        error_printf("No TPM backend types are available\n");
>      }
> -    fprintf(stderr, "\n");
>  }
>  
>  /*
> 

Re: [PATCH for-5.1 2/2] tpm: Improve help on TPM types when none are available

[Stefan Berger]

On 7/23/20 8:49 AM, Philippe Mathieu-Daudé wrote:
> On 7/23/20 1:58 PM, Markus Armbruster wrote:
>> Help is a bit awkward when no TPM types are built into QEMU:
>>
>>      $ upstream-qemu -tpmdev nonexistent,id=tpm0
>>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>>      Supported TPM types (choose only one):
>>
>> Improve to
>>
>>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>>      No TPM backend types are available
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>


Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>


>
>> ---
>>   tpm.c | 13 +++++++++----
>>   1 file changed, 9 insertions(+), 4 deletions(-)
>>
>> diff --git a/tpm.c b/tpm.c
>> index f6045bb6da..cab206355a 100644
>> --- a/tpm.c
>> +++ b/tpm.c
>> @@ -47,18 +47,23 @@ tpm_be_find_by_type(enum TpmType type)
>>    */
>>   static void tpm_display_backend_drivers(void)
>>   {
>> +    bool got_one = false;
>>       int i;
>>   
>> -    fprintf(stderr, "Supported TPM types (choose only one):\n");
>> -
>>       for (i = 0; i < TPM_TYPE__MAX; i++) {
>>           const TPMBackendClass *bc = tpm_be_find_by_type(i);
>>           if (!bc) {
>>               continue;
>>           }
>> -        fprintf(stderr, "%12s   %s\n", TpmType_str(i), bc->desc);
>> +        if (!got_one) {
>> +            error_printf("Supported TPM types (choose only one):\n");
>> +            got_one = true;
>> +        }
>> +        error_printf("%12s   %s\n", TpmType_str(i), bc->desc);
>> +    }
>> +    if (!got_one) {
>> +        error_printf("No TPM backend types are available\n");
>>       }
>> -    fprintf(stderr, "\n");
>>   }
>>   
>>   /*
>>

Re: [PATCH for-5.1 2/2] tpm: Improve help on TPM types when none are available

[Stefan Berger]

On 7/23/20 7:58 AM, Markus Armbruster wrote:
> Help is a bit awkward when no TPM types are built into QEMU:
>
>      $ upstream-qemu -tpmdev nonexistent,id=tpm0

I hope you don't mind me replacing 'upstream-qemu' with 
'x86_64-softmmu/qemu-system-x86_64'?

>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type


and this one with 'qemu-system-x86_64:'


>      Supported TPM types (choose only one):
>
> Improve to
>
>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>      No TPM backend types are available'


I hope you don't mind me replacing 'upstream-qemu' with 
'x86_64-softmmu/qemu-system-x86_64'?

    Stefan

Re: [PATCH for-5.1 2/2] tpm: Improve help on TPM types when none are available

[Markus Armbruster]

Stefan Berger <stefanb@linux.ibm.com> writes:

> On 7/23/20 7:58 AM, Markus Armbruster wrote:
>> Help is a bit awkward when no TPM types are built into QEMU:
>>
>>      $ upstream-qemu -tpmdev nonexistent,id=tpm0
>
> I hope you don't mind me replacing 'upstream-qemu' with
> 'x86_64-softmmu/qemu-system-x86_64'?
>
>>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>
>
> and this one with 'qemu-system-x86_64:'
>
>
>>      Supported TPM types (choose only one):
>>
>> Improve to
>>
>>      upstream-qemu: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>>      No TPM backend types are available'
>
>
> I hope you don't mind me replacing 'upstream-qemu' with
> 'x86_64-softmmu/qemu-system-x86_64'?

On the contrary!  I meant to replace by qemu-system-x86_64 (no directory
part), but forgot.

Thanks!