Re: [PATCH v2 13/13] OvmfPkg/BaseMemEncryptSevLib: remove Flush parameter


Laszlo Ersek
 

On 05/13/21 01:46, Brijesh Singh wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

The Flush parameter is used to provide a hint whether the specified range
is Mmio address. Now that we have a dedicated helper to clear the
memory encryption mask for the Mmio address range, its safe to remove the
Flush parameter from MemEncryptSev{Set,Clear}PageEncMask().

Since the address specified in the MemEncryptSev{Set,Clear}PageEncMask()
points to a system RAM, thus a cache flush is required during the
encryption mask update.

Cc: James Bottomley <jejb@...>
Cc: Min Xu <min.m.xu@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Tom Lendacky <thomas.lendacky@...>
Cc: Jordan Justen <jordan.l.justen@...>
Cc: Ard Biesheuvel <ardb+tianocore@...>
Cc: Laszlo Ersek <lersek@...>
Cc: Erdem Aktas <erdemaktas@...>
Signed-off-by: Brijesh Singh <brijesh.singh@...>
---
OvmfPkg/Include/Library/MemEncryptSevLib.h | 10 ++--------
.../BaseMemEncryptSevLib/X64/VirtualMemory.h | 10 ++--------
OvmfPkg/AmdSevDxe/AmdSevDxe.c | 3 +--
OvmfPkg/IoMmuDxe/AmdSevIoMmu.c | 6 ++----
.../BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c | 10 ++--------
.../BaseMemEncryptSevLib/X64/MemEncryptSevLib.c | 16 ++++------------
.../X64/PeiDxeVirtualMemory.c | 14 ++++----------
.../BaseMemEncryptSevLib/X64/SecVirtualMemory.c | 8 ++------
.../SmmCpuFeaturesLib/SmmCpuFeaturesLib.c | 3 +--
OvmfPkg/PlatformPei/AmdSev.c | 3 +--
10 files changed, 21 insertions(+), 62 deletions(-)
Reviewed-by: Laszlo Ersek <lersek@...>

(v2 patches 10 through 12 are OK as well)

Thanks
Laszlo


diff --git a/OvmfPkg/Include/Library/MemEncryptSevLib.h b/OvmfPkg/Include/Library/MemEncryptSevLib.h
index b91490d5d44d..76d06c206c8b 100644
--- a/OvmfPkg/Include/Library/MemEncryptSevLib.h
+++ b/OvmfPkg/Include/Library/MemEncryptSevLib.h
@@ -100,8 +100,6 @@ MemEncryptSevIsEnabled (
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before clearing the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -114,8 +112,7 @@ EFIAPI
MemEncryptSevClearPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
);

/**
@@ -128,8 +125,6 @@ MemEncryptSevClearPageEncMask (
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before setting the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were set for the memory
region.
@@ -142,8 +137,7 @@ EFIAPI
MemEncryptSevSetPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
);


diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
index 8dc39e647b90..21bbbd1c4f9c 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
@@ -58,8 +58,6 @@ InternalGetMemEncryptionAddressMask (
@param[in] PhysicalAddress The physical address that is the start
address of a memory region.
@param[in] Length The length of memory region
- @param[in] Flush Flush the caches before applying the
- encryption mask

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -72,8 +70,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryDecrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
);

/**
@@ -85,8 +82,6 @@ InternalMemEncryptSevSetMemoryDecrypted (
@param[in] PhysicalAddress The physical address that is the start
address of a memory region.
@param[in] Length The length of memory region
- @param[in] Flush Flush the caches before applying the
- encryption mask

@retval RETURN_SUCCESS The attributes were set for the memory
region.
@@ -99,8 +94,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryEncrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
);

/**
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
index 80831b81facf..c66c4e9b9272 100644
--- a/OvmfPkg/AmdSevDxe/AmdSevDxe.c
+++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
@@ -120,8 +120,7 @@ AmdSevDxeEntryPoint (
Status = MemEncryptSevClearPageEncMask (
0, // Cr3BaseAddress -- use current CR3
MapPagesBase, // BaseAddress
- MapPagesCount, // NumPages
- TRUE // Flush
+ MapPagesCount // NumPages
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: MemEncryptSevClearPageEncMask(): %r\n",
diff --git a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
index 49ffa2448811..b30628078f73 100644
--- a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
+++ b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
@@ -252,8 +252,7 @@ IoMmuMap (
Status = MemEncryptSevClearPageEncMask (
0,
MapInfo->PlainTextAddress,
- MapInfo->NumberOfPages,
- TRUE
+ MapInfo->NumberOfPages
);
ASSERT_EFI_ERROR (Status);
if (EFI_ERROR (Status)) {
@@ -407,8 +406,7 @@ IoMmuUnmapWorker (
Status = MemEncryptSevSetPageEncMask (
0,
MapInfo->PlainTextAddress,
- MapInfo->NumberOfPages,
- TRUE
+ MapInfo->NumberOfPages
);
ASSERT_EFI_ERROR (Status);
if (EFI_ERROR (Status)) {
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
index 169d3118e44f..be260e0d1014 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
@@ -25,8 +25,6 @@
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before clearing the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -39,8 +37,7 @@ EFIAPI
MemEncryptSevClearPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
)
{
//
@@ -59,8 +56,6 @@ MemEncryptSevClearPageEncMask (
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before setting the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were set for the memory
region.
@@ -73,8 +68,7 @@ EFIAPI
MemEncryptSevSetPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
)
{
//
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
index a2bf698bcde7..a57e8fd37fa7 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
@@ -27,8 +27,6 @@
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before clearing the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -41,15 +39,13 @@ EFIAPI
MemEncryptSevClearPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
)
{
return InternalMemEncryptSevSetMemoryDecrypted (
Cr3BaseAddress,
BaseAddress,
- EFI_PAGES_TO_SIZE (NumPages),
- Flush
+ EFI_PAGES_TO_SIZE (NumPages)
);
}

@@ -63,8 +59,6 @@ MemEncryptSevClearPageEncMask (
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
- @param[in] Flush Flush the caches before setting the bit
- (mostly TRUE except MMIO addresses)

@retval RETURN_SUCCESS The attributes were set for the memory
region.
@@ -77,15 +71,13 @@ EFIAPI
MemEncryptSevSetPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
- IN UINTN NumPages,
- IN BOOLEAN Flush
+ IN UINTN NumPages
)
{
return InternalMemEncryptSevSetMemoryEncrypted (
Cr3BaseAddress,
BaseAddress,
- EFI_PAGES_TO_SIZE (NumPages),
- Flush
+ EFI_PAGES_TO_SIZE (NumPages)
);
}

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
index a18d336a8789..c696745f9d26 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
@@ -828,8 +828,6 @@ SetMemoryEncDec (
@param[in] PhysicalAddress The physical address that is the start
address of a memory region.
@param[in] Length The length of memory region
- @param[in] Flush Flush the caches before applying the
- encryption mask

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -842,8 +840,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryDecrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
)
{

@@ -852,7 +849,7 @@ InternalMemEncryptSevSetMemoryDecrypted (
PhysicalAddress,
Length,
ClearCBit,
- Flush
+ TRUE
);
}

@@ -865,8 +862,6 @@ InternalMemEncryptSevSetMemoryDecrypted (
@param[in] PhysicalAddress The physical address that is the start
address of a memory region.
@param[in] Length The length of memory region
- @param[in] Flush Flush the caches before applying the
- encryption mask

@retval RETURN_SUCCESS The attributes were set for the memory
region.
@@ -879,8 +874,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryEncrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
)
{
return SetMemoryEncDec (
@@ -888,7 +882,7 @@ InternalMemEncryptSevSetMemoryEncrypted (
PhysicalAddress,
Length,
SetCBit,
- Flush
+ TRUE
);
}

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
index e0d3a15e8503..a155c8729bfb 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
@@ -42,8 +42,6 @@ InternalGetMemEncryptionAddressMask (
@param[in] PhysicalAddress The physical address that is the start
address of a memory region.
@param[in] Length The length of memory region
- @param[in] Flush Flush the caches before applying the
- encryption mask

@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@@ -56,8 +54,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryDecrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
)
{
//
@@ -89,8 +86,7 @@ EFIAPI
InternalMemEncryptSevSetMemoryEncrypted (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS PhysicalAddress,
- IN UINTN Length,
- IN BOOLEAN Flush
+ IN UINTN Length
)
{
//
diff --git a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
index fdf2380974fa..c7cc5b0389c8 100644
--- a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
+++ b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
@@ -283,8 +283,7 @@ SmmCpuFeaturesSmmRelocationComplete (
Status = MemEncryptSevSetPageEncMask (
0, // Cr3BaseAddress -- use current CR3
MapPagesBase, // BaseAddress
- MapPagesCount, // NumPages
- TRUE // Flush
+ MapPagesCount // NumPages
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: MemEncryptSevSetPageEncMask(): %r\n",
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index dddffdebda4b..a8bf610022ba 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -72,8 +72,7 @@ AmdSevEsInitialize (
DecryptStatus = MemEncryptSevClearPageEncMask (
0,
GhcbBasePa + EFI_PAGES_TO_SIZE (PageCount),
- 1,
- TRUE
+ 1
);
ASSERT_RETURN_ERROR (DecryptStatus);
}

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