[PATCH v8 29/32] OvmfPkg/MemEncryptSevLib: skip page state change for Mmio address


Brijesh Singh
 

The SetMemoryEncDec() is used by the higher level routines to set or clear
the page encryption mask for system RAM and Mmio address. When SEV-SNP is
active, in addition to set/clear page mask it also updates the RMP table.
The RMP table updates are required for the system RAM address and not
the Mmio address.

Add a new parameter in SetMemoryEncDec() to tell whether the specified
address is Mmio. If its Mmio then skip the page state change in the RMP
table.

Cc: Michael Roth <michael.roth@amd.com>
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: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
.../X64/PeiDxeVirtualMemory.c | 20 ++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
index 56db1e4b6ecf..0bb86d768017 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
@@ -673,6 +673,7 @@ InternalMemEncryptSevCreateIdentityMap1G (
@param[in] Mode Set or Clear mode
@param[in] CacheFlush Flush the caches before applying the
encryption mask
+ @param[in] Mmio The physical address specified is Mmio

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -688,7 +689,8 @@ SetMemoryEncDec (
IN PHYSICAL_ADDRESS PhysicalAddress,
IN UINTN Length,
IN MAP_RANGE_MODE Mode,
- IN BOOLEAN CacheFlush
+ IN BOOLEAN CacheFlush,
+ IN BOOLEAN Mmio
)
{
PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry;
@@ -711,14 +713,15 @@ SetMemoryEncDec (

DEBUG ((
DEBUG_VERBOSE,
- "%a:%a: Cr3Base=0x%Lx Physical=0x%Lx Length=0x%Lx Mode=%a CacheFlush=%u\n",
+ "%a:%a: Cr3Base=0x%Lx Physical=0x%Lx Length=0x%Lx Mode=%a CacheFlush=%u Mmio=%u\n",
gEfiCallerBaseName,
__FUNCTION__,
Cr3BaseAddress,
PhysicalAddress,
(UINT64)Length,
(Mode == SetCBit) ? "Encrypt" : "Decrypt",
- (UINT32)CacheFlush
+ (UINT32)CacheFlush,
+ (UINT32)Mmio
));

//
@@ -760,7 +763,7 @@ SetMemoryEncDec (
//
// The InternalSetPageState() is used for setting the page state in the RMP table.
//
- if ((Mode == ClearCBit) && MemEncryptSevSnpIsEnabled ()) {
+ if (!Mmio && (Mode == ClearCBit) && MemEncryptSevSnpIsEnabled ()) {
InternalSetPageState (PhysicalAddress, EFI_SIZE_TO_PAGES (Length), SevSnpPageShared, FALSE);
}

@@ -998,7 +1001,8 @@ InternalMemEncryptSevSetMemoryDecrypted (
PhysicalAddress,
Length,
ClearCBit,
- TRUE
+ TRUE,
+ FALSE
);
}

@@ -1031,7 +1035,8 @@ InternalMemEncryptSevSetMemoryEncrypted (
PhysicalAddress,
Length,
SetCBit,
- TRUE
+ TRUE,
+ FALSE
);
}

@@ -1064,6 +1069,7 @@ InternalMemEncryptSevClearMmioPageEncMask (
PhysicalAddress,
Length,
ClearCBit,
- FALSE
+ FALSE,
+ TRUE
);
}
--
2.25.1