Re: [PATCH v2] OvmfPkg/PlatformInitLib: Fix integrity checking failed of NvVarStore in some cases

["Yao, Jiewen" <jiewen.yao@intel.com>]

Thanks for the fix.
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>

Question: Have you run tiano CI by yourself, before submit the patch?



> -----Original Message-----
> From: Lee, Chun-Yi <joeyli.kernel@gmail.com>
> Sent: Thursday, December 15, 2022 10:27 PM
> To: devel@edk2.groups.io
> Cc: Xu, Min M <min.m.xu@intel.com>; Gerd Hoffmann
> <kraxel@redhat.com>; Yao, Jiewen <jiewen.yao@intel.com>; Tom Lendacky
> <thomas.lendacky@amd.com>; James Bottomley <jejb@linux.ibm.com>;
> Aktas, Erdem <erdemaktas@google.com>; Lee, Chun-Yi <jlee@suse.com>
> Subject: [PATCH v2] OvmfPkg/PlatformInitLib: Fix integrity checking failed of
> NvVarStore in some cases
> 
> In the commit 4f173db8b4 "OvmfPkg/PlatformInitLib: Add functions for
> EmuVariableNvStore", it introduced a PlatformValidateNvVarStore() function
> for checking the integrity of NvVarStore.
> 
> In some cases when the VariableHeader->StartId is VARIABLE_DATA, the
> VariableHeader->State is not just one of the four primary states:
> VAR_IN_DELETED_TRANSITION, VAR_DELETED, VAR_HEADER_VALID_ONLY,
> VAR_ADDED.
> The state may combined two or three states, e.g.
> 
>     0x3C = (VAR_IN_DELETED_TRANSITION & VAR_ADDED) & VAR_DELETED
> or
>     0x3D = VAR_ADDED & VAR_DELETED
> 
> When the variable store has those variables, system booting/rebooting will
> hangs in a ASSERT:
> 
> NvVarStore Variable header State was invalid.
> ASSERT
> /mnt/working/source_code-
> git/edk2/OvmfPkg/Library/PlatformInitLib/Platform.c(819):
> ((BOOLEAN)(0==1))
> 
> Adding more log to UpdateVariable() and PlatformValidateNvVarStore(), we
> saw some variables which have 0x3C or 0x3D state in store.
> e.g.
> 
> UpdateVariable(), VariableName=BootOrder
> L1871, State=0000003F			<-- VAR_ADDED
> State &= VAR_DELETED=0000003D
> FlushHobVariableToFlash(), VariableName=BootOrder
> ...
> UpdateVariable(), VariableName=InitialAttemptOrder
> L1977, State=0000003F
> State &= VAR_IN_DELETED_TRANSITION=0000003E
> L2376, State=0000003E
> State &= VAR_DELETED=0000003C
> FlushHobVariableToFlash(), VariableName=InitialAttemptOrder
> ...
> UpdateVariable(), VariableName=ConIn
> L1977, State=0000003F
> State &= VAR_IN_DELETED_TRANSITION=0000003E
> L2376, State=0000003E
> State &= VAR_DELETED=0000003C
> FlushHobVariableToFlash(), VariableName=ConIn
> ...
> 
> So, only allowing the four primary states is not enough. This patch changes
> the falid states list (Follow Jiewen Yao's suggestion):
> 
> 1. VAR_HEADER_VALID_ONLY (0x7F)
> 	- Header added (*)
> 2. VAR_ADDED (0x3F)
> 	- Header + data added
> 3. VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
> 	- marked as deleted, but still valid, before new data is added. (*)
> 4. VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED (0x3C)
> 	- deleted, after new data is added.
> 5. VAR_ADDED & VAR_DELETED (0x3D)
> 	- deleted directly, without new data.
> (*) means to support surprise shutdown.
> 
> And removed (VAR_IN_DELETED_TRANSITION) and (VAR_DELETED) because
> they are
> invalid states.
> 
> v2:
> Follow Jiewen Yao's suggestion to add the following valid states:
> 	VAR_ADDED & VAR_DELETED (0x3D)
> 	VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
> 	VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED
> (0x3C)
> and removed the following invalid states:
> 	VAR_IN_DELETED_TRANSITION
> 	VAR_DELETED
> 
> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
> ---
>  OvmfPkg/Library/PlatformInitLib/Platform.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/OvmfPkg/Library/PlatformInitLib/Platform.c
> b/OvmfPkg/Library/PlatformInitLib/Platform.c
> index 77f22de046..6963c47e0b 100644
> --- a/OvmfPkg/Library/PlatformInitLib/Platform.c
> +++ b/OvmfPkg/Library/PlatformInitLib/Platform.c
> @@ -702,10 +702,11 @@ PlatformValidateNvVarStore (
> 
>        VariableOffset = NvVarStoreHeader->Size - sizeof
> (VARIABLE_STORE_HEADER);
>      } else {
> -      if (!((VariableHeader->State == VAR_IN_DELETED_TRANSITION) ||
> -            (VariableHeader->State == VAR_DELETED) ||
> -            (VariableHeader->State == VAR_HEADER_VALID_ONLY) ||
> -            (VariableHeader->State == VAR_ADDED)))
> +      if (!((VariableHeader->State == VAR_HEADER_VALID_ONLY) ||
> +	    (VariableHeader->State == VAR_ADDED) ||
> +	    (VariableHeader->State == (VAR_ADDED & VAR_DELETED)) ||
> +	    (VariableHeader->State == (VAR_ADDED &
> VAR_IN_DELETED_TRANSITION)) ||
> +	    (VariableHeader->State == (VAR_ADDED &
> VAR_IN_DELETED_TRANSITION & VAR_DELETED))))
>        {
>          DEBUG ((DEBUG_ERROR, "NvVarStore Variable header State was
> invalid.\n"));
>          return FALSE;
> --
> 2.35.3