[PATCH 2/2] efi_runtime: add UEFI runtime service QueryVariableInfo interface

[IvanHu]

Hi Kengyu,

This interface will call the RT service via virt_efi_query_variable_info 
function in efi.c below:

static efi_status_t virt_efi_query_variable_info(u32 attr,
						 u64 *storage_space,
						 u64 *remaining_space,
						 u64 *max_variable_size)
{
	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	return efi_call_virt4(query_variable_info, attr, storage_space,
			      remaining_space, max_variable_size);
}

I dumped the value runtime_version equal 0 and it seems that the value 
of runtime_version doesn't be set. I think the kernel may not implement 
to check the version. I did a simple test as well, just removed the 
checking runtime version, directly call the efi_call_virt4, the function 
worked fine.

On 10/03/2012 04:10 PM, Keng-Yu Lin wrote:
> Hi Ivan,
>    The commit log looks like a bug in the kernel you found while you
> were implementing this patch.
>    Do you have further analysis or idea on the cause or how it can be
> potentially fixed we can probably help out here?
>
> On Fri, Sep 28, 2012 at 4:26 PM, Ivan Hu <ivan.hu at canonical.com> wrote:
>> This interface is always returned EFI_UNSUPPORTED from
>> virt_fei_query_variable_info on kernel driver efi.c because of checking
>> the runtime_version. It seems that runtime_version value always 0,
>> it alway returns EFI_UNSUPPORTED. Need a patch of efi.c for this interface.
>>
>> Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
>> ---
>>   efi_runtime/efi_runtime.c |   20 ++++++++++++++++++++
>>   efi_runtime/efi_runtime.h |   11 +++++++++++
>>   2 files changed, 31 insertions(+)
>>
>> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
>> index 227a910..0e66e94 100644
>> --- a/efi_runtime/efi_runtime.c
>> +++ b/efi_runtime/efi_runtime.c
>> @@ -117,6 +117,8 @@ static long efi_runtime_ioctl(struct file *file, unsigned int cmd,
>>          struct efi_getnextvariablename __user *pgetnextvariablename;
>>          unsigned long name_size;
>>
>> +       struct efi_queryvariableinfo __user *pqueryvariableinfo;
>> +
>>          switch (cmd) {
>>          case EFI_RUNTIME_GET_VARIABLE:
>>                  pgetvariable = (struct efi_getvariable __user *)arg;
>> @@ -261,6 +263,24 @@ static long efi_runtime_ioctl(struct file *file, unsigned int cmd,
>>                                                  &vendor_guid, sizeof(EFI_GUID)))
>>                          return -EFAULT;
>>                  return 0;
>> +
>> +       case EFI_RUNTIME_QUERY_VARIABLEINFO:
>> +
>> +               pqueryvariableinfo = (struct efi_queryvariableinfo __user *)arg;
>> +
>> +               if (get_user(attr, &pqueryvariableinfo->Attributes))
>> +                       return -EFAULT;
>> +
>> +               status = efi.query_variable_info(attr,
>> +                               pqueryvariableinfo->MaximumVariableStorageSize,
>> +                               pqueryvariableinfo->RemainingVariableStorageSize
>> +                               , pqueryvariableinfo->MaximumVariableSize);
>> +               if (put_user(status, pqueryvariableinfo->status))
>> +                       return -EFAULT;
>> +               if (status != EFI_SUCCESS)
>> +                       return -EINVAL;
>> +
>> +               return 0;
>>          }
>>
>>          return -ENOTTY;
>> diff --git a/efi_runtime/efi_runtime.h b/efi_runtime/efi_runtime.h
>> index 7387406..cc33878 100644
>> --- a/efi_runtime/efi_runtime.h
>> +++ b/efi_runtime/efi_runtime.h
>> @@ -73,6 +73,14 @@ struct efi_getnextvariablename {
>>          uint64_t        *status;
>>   } __attribute__ ((packed));
>>
>> +struct efi_queryvariableinfo {
>> +       uint32_t        Attributes;
>> +       uint64_t        *MaximumVariableStorageSize;
>> +       uint64_t        *RemainingVariableStorageSize;
>> +       uint64_t        *MaximumVariableSize;
>> +       uint64_t        *status;
>> +} __attribute__ ((packed));
>> +
>>   struct efi_gettime {
>>          EFI_TIME                *Time;
>>          EFI_TIME_CAPABILITIES   *Capabilities;
>> @@ -116,4 +124,7 @@ struct efi_setwakeuptime {
>>   #define EFI_RUNTIME_GET_NEXTVARIABLENAME \
>>          _IOWR('p', 0x07, struct efi_getnextvariablename)
>>
>> +#define EFI_RUNTIME_QUERY_VARIABLEINFO \
>> +       _IOR('p', 0x08, struct efi_queryvariableinfo)
>> +
>>   #endif /* _EFI_RUNTIME_H_ */
>> --
>> 1.7.9.5
>>
>>
>> --
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>