diff mbox series

[v2,1/3] efi_loader: enable QueryVariableInfo at runtime for file backed variables

Message ID 20240425051821.338842-1-ilias.apalodimas@linaro.org
State Accepted
Commit 9677192c145f2144592892f13de0e2069bcdf4ba
Headers show
Series [v2,1/3] efi_loader: enable QueryVariableInfo at runtime for file backed variables | expand

Commit Message

Ilias Apalodimas April 25, 2024, 5:18 a.m. UTC 
Since commit c28d32f946f0 ("efi_loader: conditionally enable SetvariableRT")
we are enabling the last bits of missing runtime services.
Add support for QueryVariableInfo which we already support at boottime
and we just need to mark some fucntions available at runtime and move
some checks around.

It's worth noting that pointer checks for maxmimum and remaining
variable storage aren't when we store variables on the RPMB, since the
Secure World backend is already performing them.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
Changes since v1:
- require EFI_VARIABLE_RUNTIME_ACCESS to be set at runtime
- return EFI_UNSUPPORTED for auth variables
 lib/efi_loader/efi_runtime.c                  |  4 +++
 lib/efi_loader/efi_var_common.c               |  6 -----
 lib/efi_loader/efi_variable.c                 | 25 ++++++++++++++-----
 lib/efi_loader/efi_variable_tee.c             |  5 ++++
 .../efi_selftest_variables_runtime.c          | 14 ++++++++---
 5 files changed, 39 insertions(+), 15 deletions(-)

--
2.40.1

Comments

Heinrich Schuchardt April 25, 2024, 8:32 a.m. UTC | #1 
On 25.04.24 07:18, Ilias Apalodimas wrote:
> Since commit c28d32f946f0 ("efi_loader: conditionally enable SetvariableRT")
> we are enabling the last bits of missing runtime services.
> Add support for QueryVariableInfo which we already support at boottime
> and we just need to mark some fucntions available at runtime and move
> some checks around.
>
> It's worth noting that pointer checks for maxmimum and remaining
> variable storage aren't when we store variables on the RPMB, since the
> Secure World backend is already performing them.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
> Changes since v1:
> - require EFI_VARIABLE_RUNTIME_ACCESS to be set at runtime
> - return EFI_UNSUPPORTED for auth variables
>   lib/efi_loader/efi_runtime.c                  |  4 +++
>   lib/efi_loader/efi_var_common.c               |  6 -----
>   lib/efi_loader/efi_variable.c                 | 25 ++++++++++++++-----
>   lib/efi_loader/efi_variable_tee.c             |  5 ++++
>   .../efi_selftest_variables_runtime.c          | 14 ++++++++---
>   5 files changed, 39 insertions(+), 15 deletions(-)
>
> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> index 73831c527e00..011bcd04836d 100644
> --- a/lib/efi_loader/efi_runtime.c
> +++ b/lib/efi_loader/efi_runtime.c
> @@ -129,6 +129,10 @@ efi_status_t efi_init_runtime_supported(void)
>   				EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP |
>   				EFI_RT_SUPPORTED_CONVERT_POINTER;
>
> +	if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE))
> +		rt_table->runtime_services_supported |=
> +			EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO;
> +
>   	if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
>   		u8 s = 0;
>
> diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> index 961139f005af..ea8d2a4cf98c 100644
> --- a/lib/efi_loader/efi_var_common.c
> +++ b/lib/efi_loader/efi_var_common.c
> @@ -1,4 +1,3 @@
> -// SPDX-License-Identifier: GPL-2.0+
>   /*
>    * UEFI runtime variable services
>    *
> @@ -163,11 +162,6 @@ efi_status_t EFIAPI efi_query_variable_info(
>   	EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size,
>   		  remaining_variable_storage_size, maximum_variable_size);
>
> -	if (!maximum_variable_storage_size ||
> -	    !remaining_variable_storage_size ||
> -	    !maximum_variable_size)
> -		return EFI_EXIT(EFI_INVALID_PARAMETER);
> -
>   	ret = efi_query_variable_info_int(attributes,
>   					  maximum_variable_storage_size,
>   					  remaining_variable_storage_size,
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index 0cbed53d1dbf..1cc02acb3b26 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -406,12 +406,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
>   	return EFI_SUCCESS;
>   }
>
> -efi_status_t efi_query_variable_info_int(u32 attributes,
> -					 u64 *maximum_variable_storage_size,
> -					 u64 *remaining_variable_storage_size,
> -					 u64 *maximum_variable_size)
> +efi_status_t __efi_runtime
> +efi_query_variable_info_int(u32 attributes,
> +			    u64 *maximum_variable_storage_size,
> +			    u64 *remaining_variable_storage_size,
> +			    u64 *maximum_variable_size)
>   {
> -	if (attributes == 0)
> +	if (!maximum_variable_storage_size ||
> +	    !remaining_variable_storage_size ||
> +	    !maximum_variable_size || !attributes)
>   		return EFI_INVALID_PARAMETER;
>
>   	/* EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated */
> @@ -460,7 +463,17 @@ static efi_status_t __efi_runtime EFIAPI efi_query_variable_info_runtime(
>   			u64 *remaining_variable_storage_size,
>   			u64 *maximum_variable_size)
>   {
> -	return EFI_UNSUPPORTED;

According to the UEFI 2.10 specification EFI_UNSUPPORTED must be returned if

"The attribute is not supported on this platform, and the
MaximumVariableStorageSize, RemainingVariableStorageSize,
MaximumVariableSize are undefined."

I wonder if in the spec the 'and' should be replaced by 'or'.

I guess we should return EFI_UNSUPPORTED if
CONFIG_EFI_VARIABLE_RUNTIME_ACCESS=n and change the corresponding test
accordingly. This check should be placed first.

Best regards

Heinrich

> +	if (!(attributes & EFI_VARIABLE_RUNTIME_ACCESS))
> +		return EFI_INVALID_PARAMETER;
> +	if ((attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS |
> +			   EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS |
> +			   EFI_VARIABLE_ENHANCED_AUTHENTICATED_ACCESS)))
> +		return EFI_UNSUPPORTED;
> +
> +	return efi_query_variable_info_int(attributes,
> +					   maximum_variable_storage_size,
> +					   remaining_variable_storage_size,
> +					   maximum_variable_size);
>   }
>
>   /**
> diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
> index 4f1aa298da13..8b6b0a390869 100644
> --- a/lib/efi_loader/efi_variable_tee.c
> +++ b/lib/efi_loader/efi_variable_tee.c
> @@ -873,6 +873,11 @@ efi_status_t efi_query_variable_info_int(u32 attributes,
>   	efi_status_t ret;
>   	u8 *comm_buf;
>
> +	if (!max_variable_storage_size ||
> +	    !remain_variable_storage_size ||
> +	    !max_variable_size || !attributes)
> +		return EFI_INVALID_PARAMETER;
> +
>   	payload_size = sizeof(*mm_query_info);
>   	comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
>   				SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
> diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
> index afa91be62c85..5794a7b2d405 100644
> --- a/lib/efi_selftest/efi_selftest_variables_runtime.c
> +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
> @@ -60,9 +60,17 @@ static int execute(void)
>   	ret = runtime->query_variable_info(EFI_VARIABLE_BOOTSERVICE_ACCESS,
>   					   &max_storage, &rem_storage,
>   					   &max_size);
> -	if (ret != EFI_UNSUPPORTED) {
> -		efi_st_error("QueryVariableInfo failed\n");
> -		return EFI_ST_FAILURE;
> +
> +	if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE)) {
> +		if (ret != EFI_SUCCESS) {
> +			efi_st_error("QueryVariableInfo failed\n");
> +			return EFI_ST_FAILURE;
> +		}
> +	} else {
> +		if (ret != EFI_UNSUPPORTED) {
> +			efi_st_error("QueryVariableInfo failed\n");
> +			return EFI_ST_FAILURE;
> +		}
>   	}
>
>   	ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0,
> --
> 2.40.1
>
Ilias Apalodimas April 25, 2024, 10:25 a.m. UTC | #2 
Hi Heinrich,

On Thu, 25 Apr 2024 at 11:32, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> On 25.04.24 07:18, Ilias Apalodimas wrote:
> > Since commit c28d32f946f0 ("efi_loader: conditionally enable SetvariableRT")
> > we are enabling the last bits of missing runtime services.
> > Add support for QueryVariableInfo which we already support at boottime
> > and we just need to mark some fucntions available at runtime and move
> > some checks around.
> >
> > It's worth noting that pointer checks for maxmimum and remaining
> > variable storage aren't when we store variables on the RPMB, since the
> > Secure World backend is already performing them.
> >
> > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> > ---
> > Changes since v1:
> > - require EFI_VARIABLE_RUNTIME_ACCESS to be set at runtime
> > - return EFI_UNSUPPORTED for auth variables
> >   lib/efi_loader/efi_runtime.c                  |  4 +++
> >   lib/efi_loader/efi_var_common.c               |  6 -----
> >   lib/efi_loader/efi_variable.c                 | 25 ++++++++++++++-----
> >   lib/efi_loader/efi_variable_tee.c             |  5 ++++
> >   .../efi_selftest_variables_runtime.c          | 14 ++++++++---
> >   5 files changed, 39 insertions(+), 15 deletions(-)
> >
> > diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> > index 73831c527e00..011bcd04836d 100644
> > --- a/lib/efi_loader/efi_runtime.c
> > +++ b/lib/efi_loader/efi_runtime.c
> > @@ -129,6 +129,10 @@ efi_status_t efi_init_runtime_supported(void)
> >                               EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP |
> >                               EFI_RT_SUPPORTED_CONVERT_POINTER;
> >
> > +     if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE))
> > +             rt_table->runtime_services_supported |=
> > +                     EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO;
> > +
> >       if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
> >               u8 s = 0;
> >
> > diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> > index 961139f005af..ea8d2a4cf98c 100644
> > --- a/lib/efi_loader/efi_var_common.c
> > +++ b/lib/efi_loader/efi_var_common.c
> > @@ -1,4 +1,3 @@
> > -// SPDX-License-Identifier: GPL-2.0+
> >   /*
> >    * UEFI runtime variable services
> >    *
> > @@ -163,11 +162,6 @@ efi_status_t EFIAPI efi_query_variable_info(
> >       EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size,
> >                 remaining_variable_storage_size, maximum_variable_size);
> >
> > -     if (!maximum_variable_storage_size ||
> > -         !remaining_variable_storage_size ||
> > -         !maximum_variable_size)
> > -             return EFI_EXIT(EFI_INVALID_PARAMETER);
> > -
> >       ret = efi_query_variable_info_int(attributes,
> >                                         maximum_variable_storage_size,
> >                                         remaining_variable_storage_size,
> > diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> > index 0cbed53d1dbf..1cc02acb3b26 100644
> > --- a/lib/efi_loader/efi_variable.c
> > +++ b/lib/efi_loader/efi_variable.c
> > @@ -406,12 +406,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
> >       return EFI_SUCCESS;
> >   }
> >
> > -efi_status_t efi_query_variable_info_int(u32 attributes,
> > -                                      u64 *maximum_variable_storage_size,
> > -                                      u64 *remaining_variable_storage_size,
> > -                                      u64 *maximum_variable_size)
> > +efi_status_t __efi_runtime
> > +efi_query_variable_info_int(u32 attributes,
> > +                         u64 *maximum_variable_storage_size,
> > +                         u64 *remaining_variable_storage_size,
> > +                         u64 *maximum_variable_size)
> >   {
> > -     if (attributes == 0)
> > +     if (!maximum_variable_storage_size ||
> > +         !remaining_variable_storage_size ||
> > +         !maximum_variable_size || !attributes)
> >               return EFI_INVALID_PARAMETER;
> >
> >       /* EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated */
> > @@ -460,7 +463,17 @@ static efi_status_t __efi_runtime EFIAPI efi_query_variable_info_runtime(
> >                       u64 *remaining_variable_storage_size,
> >                       u64 *maximum_variable_size)
> >   {
> > -     return EFI_UNSUPPORTED;
>
> According to the UEFI 2.10 specification EFI_UNSUPPORTED must be returned if
>
> "The attribute is not supported on this platform, and the
> MaximumVariableStorageSize, RemainingVariableStorageSize,
> MaximumVariableSize are undefined."
>
> I wonder if in the spec the 'and' should be replaced by 'or'.

Probably 'or'

>
> I guess we should return EFI_UNSUPPORTED if
> CONFIG_EFI_VARIABLE_RUNTIME_ACCESS=n and change the corresponding test
> accordingly. This check should be placed first.

The spec isn't clear indeed, but looking at the flags usually passed
in QueyVariable, there's nothing that checks for SetVariable at
runtime -- which isn't even an attr, it's a property of the RT_PROP
table.
We do return EFI_UNSUPPORTED for authenticated variables, which we
can't reliably support (and auth variables have their own attr).
I would prefer merging this with the existing checks and in the future
(perhaps the next stable release) make CONFIG_EFI_RT_VOLATILE_STORE=y
by default or get rid of the config options entirely once the
userspace tools are mature enough to support it.

In any case, I don't have a strong opinion, I am fine with both. Just
tell me what you prefer.

Regards
/Ilias

>
> Best regards
>
> Heinrich
>
> > +     if (!(attributes & EFI_VARIABLE_RUNTIME_ACCESS))
> > +             return EFI_INVALID_PARAMETER;
> > +     if ((attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS |
> > +                        EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS |
> > +                        EFI_VARIABLE_ENHANCED_AUTHENTICATED_ACCESS)))
> > +             return EFI_UNSUPPORTED;
> > +
> > +     return efi_query_variable_info_int(attributes,
> > +                                        maximum_variable_storage_size,
> > +                                        remaining_variable_storage_size,
> > +                                        maximum_variable_size);
> >   }
> >
> >   /**
> > diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
> > index 4f1aa298da13..8b6b0a390869 100644
> > --- a/lib/efi_loader/efi_variable_tee.c
> > +++ b/lib/efi_loader/efi_variable_tee.c
> > @@ -873,6 +873,11 @@ efi_status_t efi_query_variable_info_int(u32 attributes,
> >       efi_status_t ret;
> >       u8 *comm_buf;
> >
> > +     if (!max_variable_storage_size ||
> > +         !remain_variable_storage_size ||
> > +         !max_variable_size || !attributes)
> > +             return EFI_INVALID_PARAMETER;
> > +
> >       payload_size = sizeof(*mm_query_info);
> >       comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
> >                               SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
> > diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
> > index afa91be62c85..5794a7b2d405 100644
> > --- a/lib/efi_selftest/efi_selftest_variables_runtime.c
> > +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
> > @@ -60,9 +60,17 @@ static int execute(void)
> >       ret = runtime->query_variable_info(EFI_VARIABLE_BOOTSERVICE_ACCESS,
> >                                          &max_storage, &rem_storage,
> >                                          &max_size);
> > -     if (ret != EFI_UNSUPPORTED) {
> > -             efi_st_error("QueryVariableInfo failed\n");
> > -             return EFI_ST_FAILURE;
> > +
> > +     if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE)) {
> > +             if (ret != EFI_SUCCESS) {
> > +                     efi_st_error("QueryVariableInfo failed\n");
> > +                     return EFI_ST_FAILURE;
> > +             }
> > +     } else {
> > +             if (ret != EFI_UNSUPPORTED) {
> > +                     efi_st_error("QueryVariableInfo failed\n");
> > +                     return EFI_ST_FAILURE;
> > +             }
> >       }
> >
> >       ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0,
> > --
> > 2.40.1
> >
>
diff mbox series

Patch

diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 73831c527e00..011bcd04836d 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -129,6 +129,10 @@  efi_status_t efi_init_runtime_supported(void)
 				EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP |
 				EFI_RT_SUPPORTED_CONVERT_POINTER;

+	if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE))
+		rt_table->runtime_services_supported |=
+			EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO;
+
 	if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
 		u8 s = 0;

diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index 961139f005af..ea8d2a4cf98c 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -1,4 +1,3 @@ 
-// SPDX-License-Identifier: GPL-2.0+
 /*
  * UEFI runtime variable services
  *
@@ -163,11 +162,6 @@  efi_status_t EFIAPI efi_query_variable_info(
 	EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size,
 		  remaining_variable_storage_size, maximum_variable_size);

-	if (!maximum_variable_storage_size ||
-	    !remaining_variable_storage_size ||
-	    !maximum_variable_size)
-		return EFI_EXIT(EFI_INVALID_PARAMETER);
-
 	ret = efi_query_variable_info_int(attributes,
 					  maximum_variable_storage_size,
 					  remaining_variable_storage_size,
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 0cbed53d1dbf..1cc02acb3b26 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -406,12 +406,15 @@  efi_status_t efi_set_variable_int(const u16 *variable_name,
 	return EFI_SUCCESS;
 }

-efi_status_t efi_query_variable_info_int(u32 attributes,
-					 u64 *maximum_variable_storage_size,
-					 u64 *remaining_variable_storage_size,
-					 u64 *maximum_variable_size)
+efi_status_t __efi_runtime
+efi_query_variable_info_int(u32 attributes,
+			    u64 *maximum_variable_storage_size,
+			    u64 *remaining_variable_storage_size,
+			    u64 *maximum_variable_size)
 {
-	if (attributes == 0)
+	if (!maximum_variable_storage_size ||
+	    !remaining_variable_storage_size ||
+	    !maximum_variable_size || !attributes)
 		return EFI_INVALID_PARAMETER;

 	/* EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated */
@@ -460,7 +463,17 @@  static efi_status_t __efi_runtime EFIAPI efi_query_variable_info_runtime(
 			u64 *remaining_variable_storage_size,
 			u64 *maximum_variable_size)
 {
-	return EFI_UNSUPPORTED;
+	if (!(attributes & EFI_VARIABLE_RUNTIME_ACCESS))
+		return EFI_INVALID_PARAMETER;
+	if ((attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS |
+			   EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS |
+			   EFI_VARIABLE_ENHANCED_AUTHENTICATED_ACCESS)))
+		return EFI_UNSUPPORTED;
+
+	return efi_query_variable_info_int(attributes,
+					   maximum_variable_storage_size,
+					   remaining_variable_storage_size,
+					   maximum_variable_size);
 }

 /**
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 4f1aa298da13..8b6b0a390869 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -873,6 +873,11 @@  efi_status_t efi_query_variable_info_int(u32 attributes,
 	efi_status_t ret;
 	u8 *comm_buf;

+	if (!max_variable_storage_size ||
+	    !remain_variable_storage_size ||
+	    !max_variable_size || !attributes)
+		return EFI_INVALID_PARAMETER;
+
 	payload_size = sizeof(*mm_query_info);
 	comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
 				SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
index afa91be62c85..5794a7b2d405 100644
--- a/lib/efi_selftest/efi_selftest_variables_runtime.c
+++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
@@ -60,9 +60,17 @@  static int execute(void)
 	ret = runtime->query_variable_info(EFI_VARIABLE_BOOTSERVICE_ACCESS,
 					   &max_storage, &rem_storage,
 					   &max_size);
-	if (ret != EFI_UNSUPPORTED) {
-		efi_st_error("QueryVariableInfo failed\n");
-		return EFI_ST_FAILURE;
+
+	if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE)) {
+		if (ret != EFI_SUCCESS) {
+			efi_st_error("QueryVariableInfo failed\n");
+			return EFI_ST_FAILURE;
+		}
+	} else {
+		if (ret != EFI_UNSUPPORTED) {
+			efi_st_error("QueryVariableInfo failed\n");
+			return EFI_ST_FAILURE;
+		}
 	}

 	ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0,