OvmfPkg/BaseMemEncryptSevLib: introduce MemEncryptSevClearMmioPageEncMask()

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

The MemEncryptSevClearMmioPageEncMask() helper can be used for clearing
the memory encryption mask for the Mmio region.

The MemEncryptSevClearMmioPageEncMask() is a simplified version of
MemEncryptSevClearPageEncMask() -- it does not flush the caches after
clearing the page encryption mask.

Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Message-Id: <20210519181949.6574-10-brijesh.singh@amd.com>
This commit is contained in:
Brijesh Singh 2021-05-19 13:19:45 -05:00 committed by mergify[bot]
parent 2b5b2ff04d
commit 901a9bfc3a
6 changed files with 175 additions and 0 deletions

View File

@ -203,4 +203,29 @@ MemEncryptSevGetAddressRangeState (
IN UINTN Length
);
/**
This function clears memory encryption bit for the MMIO region specified by
BaseAddress and NumPages.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] BaseAddress The physical address that is the start
address of a MMIO region.
@param[in] NumPages The number of pages from start memory
region.
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Number of pages is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
MemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
IN UINTN NumPages
);
#endif // _MEM_ENCRYPT_SEV_LIB_H_

View File

@ -111,3 +111,34 @@ MemEncryptSevGetAddressRangeState (
//
return MemEncryptSevAddressRangeEncrypted;
}
/**
This function clears memory encryption bit for the MMIO region specified by
BaseAddress and NumPages.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] BaseAddress The physical address that is the start
address of a MMIO region.
@param[in] NumPages The number of pages from start memory
region.
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Number of pages is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
MemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
IN UINTN NumPages
)
{
//
// Memory encryption bit is not accessible in 32-bit mode
//
return RETURN_UNSUPPORTED;
}

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@ -118,3 +118,36 @@ MemEncryptSevGetAddressRangeState (
Length
);
}
/**
This function clears memory encryption bit for the mmio region specified by
BaseAddress and NumPages.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] BaseAddress The physical address that is the start
address of a mmio region.
@param[in] NumPages The number of pages from start memory
region.
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Number of pages is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
MemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
IN UINTN NumPages
)
{
return InternalMemEncryptSevClearMmioPageEncMask (
Cr3BaseAddress,
BaseAddress,
EFI_PAGES_TO_SIZE (NumPages)
);
}

View File

@ -891,3 +891,36 @@ InternalMemEncryptSevSetMemoryEncrypted (
Flush
);
}
/**
This function clears memory encryption bit for the MMIO region specified by
PhysicalAddress and Length.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] PhysicalAddress The physical address that is the start
address of a MMIO region.
@param[in] Length The length of memory region
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Length is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encyrption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
InternalMemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
IN UINTN Length
)
{
return SetMemoryEncDec (
Cr3BaseAddress,
PhysicalAddress,
Length,
ClearCBit,
FALSE
);
}

View File

@ -98,3 +98,33 @@ InternalMemEncryptSevSetMemoryEncrypted (
//
return RETURN_UNSUPPORTED;
}
/**
This function clears memory encryption bit for the MMIO region specified by
PhysicalAddress and Length.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] PhysicalAddress The physical address that is the start
address of a MMIO region.
@param[in] Length The length of memory region
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Length is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encyrption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
InternalMemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
IN UINTN Length
)
{
//
// This function is not available during SEC.
//
return RETURN_UNSUPPORTED;
}

View File

@ -126,4 +126,27 @@ InternalMemEncryptSevGetAddressRangeState (
IN UINTN Length
);
/**
This function clears memory encryption bit for the MMIO region specified by
PhysicalAddress and Length.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] PhysicalAddress The physical address that is the start
address of a MMIO region.
@param[in] Length The length of memory region
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Length is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encyrption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
InternalMemEncryptSevClearMmioPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
IN UINTN Length
);
#endif