From: Sophia Wolf <phiawolf@google.com>
When a guest OS does not support unaccepted memory, the unaccepted
memory must be accepted before returning a memory map to the caller.
EfiMemoryAcceptProtocol is defined in MdePkg and is implemented /
Installed in AmdSevDxe for AMD SEV-SNP memory acceptance.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
---
OvmfPkg/AmdSevDxe/AmdSevDxe.c | 55 ++++++++++++++++++--
OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 3 ++
OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c | 24 +++++++--
3 files changed, 74 insertions(+), 8 deletions(-)
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
index 662d3c4ccb..f7600c3c81 100644
--- a/OvmfPkg/AmdSevDxe/AmdSevDxe.c
+++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
@@ -20,6 +20,7 @@
#include <Library/UefiBootServicesTableLib.h>
#include <Guid/ConfidentialComputingSevSnpBlob.h>
#include <Library/PcdLib.h>
+#include <Protocol/MemoryAccept.h>
STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
SIGNATURE_32 ('A', 'M', 'D', 'E'),
@@ -31,6 +32,40 @@ STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
FixedPcdGet32 (PcdOvmfCpuidSize),
};
+STATIC EFI_HANDLE mAmdSevDxeHandle = NULL;
+
+#define IS_ALIGNED(x, y) ((((x) & ((y) - 1)) == 0))
+
+STATIC
+EFI_STATUS
+EFIAPI
+AmdSevMemoryAccept (
+ IN EDKII_MEMORY_ACCEPT_PROTOCOL *This,
+ IN EFI_PHYSICAL_ADDRESS StartAddress,
+ IN UINTN Size
+ )
+{
+ //
+ // The StartAddress must be page-aligned, and the Size must be a positive
+ // multiple of SIZE_4KB. Use an assert instead of returning an erros since
+ // this is an EDK2-internal protocol.
+ //
+ ASSERT (IS_ALIGNED (StartAddress, SIZE_4KB));
+ ASSERT (IS_ALIGNED (Size, SIZE_4KB));
+ ASSERT (Size != 0);
+
+ MemEncryptSevSnpPreValidateSystemRam (
+ StartAddress,
+ EFI_SIZE_TO_PAGES (Size)
+ );
+
+ return EFI_SUCCESS;
+}
+
+STATIC EDKII_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = {
+ AmdSevMemoryAccept
+};
+
EFI_STATUS
EFIAPI
AmdSevDxeEntryPoint (
@@ -147,11 +182,23 @@ AmdSevDxeEntryPoint (
}
}
- //
- // If its SEV-SNP active guest then install the CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
- // It contains the location for both the Secrets and CPUID page.
- //
if (MemEncryptSevSnpIsEnabled ()) {
+ //
+ // Memory acceptance began being required in SEV-SNP, so install the
+ // memory accept protocol implementation for a SEV-SNP active guest.
+ //
+ Status = gBS->InstallProtocolInterface (
+ &mAmdSevDxeHandle,
+ &gEdkiiMemoryAcceptProtocolGuid,
+ EFI_NATIVE_INTERFACE,
+ &mMemoryAcceptProtocol
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // If its SEV-SNP active guest then install the CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
+ // It contains the location for both the Secrets and CPUID page.
+ //
return gBS->InstallConfigurationTable (
&gConfidentialComputingSevSnpBlobGuid,
&mSnpBootDxeTable
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
index 9acf860cf2..cd1b686c53 100644
--- a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
+++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
@@ -47,6 +47,9 @@
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
+[Protocols]
+ gEdkiiMemoryAcceptProtocolGuid
+
[Guids]
gConfidentialComputingSevSnpBlobGuid
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
index d3a95e4913..cbcdd46f52 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
@@ -14,6 +14,7 @@
#include <Library/MemEncryptSevLib.h>
#include "SnpPageStateChange.h"
+#include "VirtualMemory.h"
/**
Pre-validate the system RAM when SEV-SNP is enabled in the guest VM.
@@ -29,12 +30,27 @@ MemEncryptSevSnpPreValidateSystemRam (
IN UINTN NumPages
)
{
+ EFI_STATUS Status;
+
if (!MemEncryptSevSnpIsEnabled ()) {
return;
}
- //
- // All the pre-validation must be completed in the PEI phase.
- //
- ASSERT (FALSE);
+ // DXE pre-validation may happen with the memory accept protocol.
+ // The protocol should only be called outside the prevalidated ranges
+ // that the PEI stage code explicitly skips. Specifically, only memory
+ // ranges that are classified as unaccepted.
+ if (BaseAddress >= SIZE_4GB) {
+ Status = InternalMemEncryptSevCreateIdentityMap1G (
+ 0,
+ BaseAddress,
+ EFI_PAGES_TO_SIZE (NumPages)
+ );
+ if (EFI_ERROR (Status)) {
+ ASSERT (FALSE);
+ CpuDeadLoop ();
+ }
+ }
+
+ InternalSetPageState (BaseAddress, NumPages, SevSnpPagePrivate, TRUE);
}
--
2.38.0.135.g90850a2211-goog
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On 10/24/22 15:41, Dionna Glaze wrote:
> From: Sophia Wolf <phiawolf@google.com>
>
> When a guest OS does not support unaccepted memory, the unaccepted
> memory must be accepted before returning a memory map to the caller.
>
> EfiMemoryAcceptProtocol is defined in MdePkg and is implemented /
> Installed in AmdSevDxe for AMD SEV-SNP memory acceptance.
>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
> OvmfPkg/AmdSevDxe/AmdSevDxe.c | 55 ++++++++++++++++++--
> OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 3 ++
> OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c | 24 +++++++--
> 3 files changed, 74 insertions(+), 8 deletions(-)
>
> diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> index 662d3c4ccb..f7600c3c81 100644
> --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> @@ -20,6 +20,7 @@
> #include <Library/UefiBootServicesTableLib.h>
> #include <Guid/ConfidentialComputingSevSnpBlob.h>
> #include <Library/PcdLib.h>
> +#include <Protocol/MemoryAccept.h>
>
> STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
> SIGNATURE_32 ('A', 'M', 'D', 'E'),
> @@ -31,6 +32,40 @@ STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
> FixedPcdGet32 (PcdOvmfCpuidSize),
> };
>
> +STATIC EFI_HANDLE mAmdSevDxeHandle = NULL;
> +
> +#define IS_ALIGNED(x, y) ((((x) & ((y) - 1)) == 0))
> +
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +AmdSevMemoryAccept (
> + IN EDKII_MEMORY_ACCEPT_PROTOCOL *This,
> + IN EFI_PHYSICAL_ADDRESS StartAddress,
> + IN UINTN Size
> + )
> +{
> + //
> + // The StartAddress must be page-aligned, and the Size must be a positive
> + // multiple of SIZE_4KB. Use an assert instead of returning an erros since
> + // this is an EDK2-internal protocol.
> + //
> + ASSERT (IS_ALIGNED (StartAddress, SIZE_4KB));
> + ASSERT (IS_ALIGNED (Size, SIZE_4KB));
> + ASSERT (Size != 0);
> +
> + MemEncryptSevSnpPreValidateSystemRam (
> + StartAddress,
> + EFI_SIZE_TO_PAGES (Size)
> + );
> +
> + return EFI_SUCCESS;
> +}
> +
> +STATIC EDKII_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = {
> + AmdSevMemoryAccept
> +};
> +
> EFI_STATUS
> EFIAPI
> AmdSevDxeEntryPoint (
> @@ -147,11 +182,23 @@ AmdSevDxeEntryPoint (
> }
> }
>
> - //
> - // If its SEV-SNP active guest then install the CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
> - // It contains the location for both the Secrets and CPUID page.
> - //
> if (MemEncryptSevSnpIsEnabled ()) {
> + //
> + // Memory acceptance began being required in SEV-SNP, so install the
> + // memory accept protocol implementation for a SEV-SNP active guest.
> + //
> + Status = gBS->InstallProtocolInterface (
> + &mAmdSevDxeHandle,
> + &gEdkiiMemoryAcceptProtocolGuid,
> + EFI_NATIVE_INTERFACE,
> + &mMemoryAcceptProtocol
> + );
> + ASSERT_EFI_ERROR (Status);
> +
> + //
> + // If its SEV-SNP active guest then install the CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
> + // It contains the location for both the Secrets and CPUID page.
> + //
> return gBS->InstallConfigurationTable (
> &gConfidentialComputingSevSnpBlobGuid,
> &mSnpBootDxeTable
> diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> index 9acf860cf2..cd1b686c53 100644
> --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> @@ -47,6 +47,9 @@
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
>
> +[Protocols]
> + gEdkiiMemoryAcceptProtocolGuid
> +
> [Guids]
> gConfidentialComputingSevSnpBlobGuid
>
> diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
> index d3a95e4913..cbcdd46f52 100644
> --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
> +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
> @@ -14,6 +14,7 @@
> #include <Library/MemEncryptSevLib.h>
>
> #include "SnpPageStateChange.h"
> +#include "VirtualMemory.h"
>
> /**
> Pre-validate the system RAM when SEV-SNP is enabled in the guest VM.
> @@ -29,12 +30,27 @@ MemEncryptSevSnpPreValidateSystemRam (
> IN UINTN NumPages
> )
> {
> + EFI_STATUS Status;
> +
> if (!MemEncryptSevSnpIsEnabled ()) {
> return;
> }
>
> - //
> - // All the pre-validation must be completed in the PEI phase.
> - //
> - ASSERT (FALSE);
> + // DXE pre-validation may happen with the memory accept protocol.
> + // The protocol should only be called outside the prevalidated ranges
> + // that the PEI stage code explicitly skips. Specifically, only memory
> + // ranges that are classified as unaccepted.
> + if (BaseAddress >= SIZE_4GB) {
> + Status = InternalMemEncryptSevCreateIdentityMap1G (
> + 0,
> + BaseAddress,
> + EFI_PAGES_TO_SIZE (NumPages)
> + );
> + if (EFI_ERROR (Status)) {
> + ASSERT (FALSE);
> + CpuDeadLoop ();
> + }
> + }
> +
> + InternalSetPageState (BaseAddress, NumPages, SevSnpPagePrivate, TRUE);
> }
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Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Need AMD-SEV people to give Reviewed-by.
Thank you
Yao, Jiewen
> -----Original Message-----
> From: Dionna Glaze <dionnaglaze@google.com>
> Sent: Tuesday, October 25, 2022 4:41 AM
> To: devel@edk2.groups.io
> Cc: Dionna Glaze <dionnaglaze@google.com>; Gerd Hoffmann
> <kraxel@redhat.com>; James Bottomley <jejb@linux.ibm.com>; Yao,
> Jiewen <jiewen.yao@intel.com>; Tom Lendacky
> <thomas.lendacky@amd.com>
> Subject: [PATCH v8 1/7] OvmfPkg: Realize EfiMemoryAcceptProtocol in
> AmdSevDxe
>
> From: Sophia Wolf <phiawolf@google.com>
>
> When a guest OS does not support unaccepted memory, the unaccepted
> memory must be accepted before returning a memory map to the caller.
>
> EfiMemoryAcceptProtocol is defined in MdePkg and is implemented /
> Installed in AmdSevDxe for AMD SEV-SNP memory acceptance.
>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
> ---
> OvmfPkg/AmdSevDxe/AmdSevDxe.c | 55
> ++++++++++++++++++--
> OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 3 ++
>
> OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.
> c | 24 +++++++--
> 3 files changed, 74 insertions(+), 8 deletions(-)
>
> diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> index 662d3c4ccb..f7600c3c81 100644
> --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c
> @@ -20,6 +20,7 @@
> #include <Library/UefiBootServicesTableLib.h>
> #include <Guid/ConfidentialComputingSevSnpBlob.h>
> #include <Library/PcdLib.h>
> +#include <Protocol/MemoryAccept.h>
>
> STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION
> mSnpBootDxeTable = {
> SIGNATURE_32 ('A', 'M', 'D', 'E'),
> @@ -31,6 +32,40 @@ STATIC
> CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
> FixedPcdGet32 (PcdOvmfCpuidSize),
> };
>
> +STATIC EFI_HANDLE mAmdSevDxeHandle = NULL;
> +
> +#define IS_ALIGNED(x, y) ((((x) & ((y) - 1)) == 0))
> +
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +AmdSevMemoryAccept (
> + IN EDKII_MEMORY_ACCEPT_PROTOCOL *This,
> + IN EFI_PHYSICAL_ADDRESS StartAddress,
> + IN UINTN Size
> + )
> +{
> + //
> + // The StartAddress must be page-aligned, and the Size must be a
> positive
> + // multiple of SIZE_4KB. Use an assert instead of returning an erros since
> + // this is an EDK2-internal protocol.
> + //
> + ASSERT (IS_ALIGNED (StartAddress, SIZE_4KB));
> + ASSERT (IS_ALIGNED (Size, SIZE_4KB));
> + ASSERT (Size != 0);
> +
> + MemEncryptSevSnpPreValidateSystemRam (
> + StartAddress,
> + EFI_SIZE_TO_PAGES (Size)
> + );
> +
> + return EFI_SUCCESS;
> +}
> +
> +STATIC EDKII_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = {
> + AmdSevMemoryAccept
> +};
> +
> EFI_STATUS
> EFIAPI
> AmdSevDxeEntryPoint (
> @@ -147,11 +182,23 @@ AmdSevDxeEntryPoint (
> }
> }
>
> - //
> - // If its SEV-SNP active guest then install the
> CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
> - // It contains the location for both the Secrets and CPUID page.
> - //
> if (MemEncryptSevSnpIsEnabled ()) {
> + //
> + // Memory acceptance began being required in SEV-SNP, so install the
> + // memory accept protocol implementation for a SEV-SNP active guest.
> + //
> + Status = gBS->InstallProtocolInterface (
> + &mAmdSevDxeHandle,
> + &gEdkiiMemoryAcceptProtocolGuid,
> + EFI_NATIVE_INTERFACE,
> + &mMemoryAcceptProtocol
> + );
> + ASSERT_EFI_ERROR (Status);
> +
> + //
> + // If its SEV-SNP active guest then install the
> CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB.
> + // It contains the location for both the Secrets and CPUID page.
> + //
> return gBS->InstallConfigurationTable (
> &gConfidentialComputingSevSnpBlobGuid,
> &mSnpBootDxeTable
> diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> index 9acf860cf2..cd1b686c53 100644
> --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf
> @@ -47,6 +47,9 @@
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
>
> +[Protocols]
> + gEdkiiMemoryAcceptProtocolGuid
> +
> [Guids]
> gConfidentialComputingSevSnpBlobGuid
>
> diff --git
> a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidat
> e.c
> b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValida
> te.c
> index d3a95e4913..cbcdd46f52 100644
> ---
> a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidat
> e.c
> +++
> b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValida
> te.c
> @@ -14,6 +14,7 @@
> #include <Library/MemEncryptSevLib.h>
>
> #include "SnpPageStateChange.h"
> +#include "VirtualMemory.h"
>
> /**
> Pre-validate the system RAM when SEV-SNP is enabled in the guest VM.
> @@ -29,12 +30,27 @@ MemEncryptSevSnpPreValidateSystemRam (
> IN UINTN NumPages
> )
> {
> + EFI_STATUS Status;
> +
> if (!MemEncryptSevSnpIsEnabled ()) {
> return;
> }
>
> - //
> - // All the pre-validation must be completed in the PEI phase.
> - //
> - ASSERT (FALSE);
> + // DXE pre-validation may happen with the memory accept protocol.
> + // The protocol should only be called outside the prevalidated ranges
> + // that the PEI stage code explicitly skips. Specifically, only memory
> + // ranges that are classified as unaccepted.
> + if (BaseAddress >= SIZE_4GB) {
> + Status = InternalMemEncryptSevCreateIdentityMap1G (
> + 0,
> + BaseAddress,
> + EFI_PAGES_TO_SIZE (NumPages)
> + );
> + if (EFI_ERROR (Status)) {
> + ASSERT (FALSE);
> + CpuDeadLoop ();
> + }
> + }
> +
> + InternalSetPageState (BaseAddress, NumPages, SevSnpPagePrivate,
> TRUE);
> }
> --
> 2.38.0.135.g90850a2211-goog
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