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| author | Dionna Glaze <dionnaglaze@google.com> | 2023-01-26 21:17:37 +0000 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2023-01-26 23:00:51 +0000 |
| commit | a00e2e5513926a4031d96dc707113d13e1cdf814 (patch) | |
| tree | 7c53dba69741788f26b7abc976ea17df21e96755 | |
| parent | ca573b86157e7fcd34cd44e79ebd10e89d8b8cc4 (diff) | |
| download | edk2-a00e2e5513926a4031d96dc707113d13e1cdf814.tar.gz edk2-a00e2e5513926a4031d96dc707113d13e1cdf814.tar.bz2 edk2-a00e2e5513926a4031d96dc707113d13e1cdf814.zip | |
OvmfPkg: Add memory acceptance event in AmdSevDxe
The added behavior is to accept all unaccepted memory at
ExitBootServices if the behavior is not disabled. This allows safe
upgrades for OS loaders to affirm their support for the unaccepted
memory type.
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>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "Min M. Xu" <min.m.xu@intel.com>
Cc: Andrew Fish <afish@apple.com>
Cc: "Michael D. Kinney" <michael.d.kinney@intel.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
| -rw-r--r-- | OvmfPkg/AmdSevDxe/AmdSevDxe.c | 97 | ||||
| -rw-r--r-- | OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 1 |
2 files changed, 98 insertions, 0 deletions
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c index f7600c3c81..37d1a3ff55 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 <Pi/PrePiDxeCis.h>
#include <Protocol/MemoryAccept.h>
STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = {
@@ -34,6 +35,10 @@ STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = { STATIC EFI_HANDLE mAmdSevDxeHandle = NULL;
+STATIC BOOLEAN mAcceptAllMemoryAtEBS = TRUE;
+
+STATIC EFI_EVENT mAcceptAllMemoryEvent = NULL;
+
#define IS_ALIGNED(x, y) ((((x) & ((y) - 1)) == 0))
STATIC
@@ -62,6 +67,82 @@ AmdSevMemoryAccept ( return EFI_SUCCESS;
}
+STATIC
+EFI_STATUS
+AcceptAllMemory (
+ VOID
+ )
+{
+ EFI_GCD_MEMORY_SPACE_DESCRIPTOR *AllDescMap;
+ UINTN NumEntries;
+ UINTN Index;
+ EFI_STATUS Status;
+
+ DEBUG ((DEBUG_INFO, "Accepting all memory\n"));
+
+ /*
+ * Get a copy of the memory space map to iterate over while
+ * changing the map.
+ */
+ Status = gDS->GetMemorySpaceMap (&NumEntries, &AllDescMap);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ for (Index = 0; Index < NumEntries; Index++) {
+ CONST EFI_GCD_MEMORY_SPACE_DESCRIPTOR *Desc;
+
+ Desc = &AllDescMap[Index];
+ if (Desc->GcdMemoryType != EFI_GCD_MEMORY_TYPE_UNACCEPTED) {
+ continue;
+ }
+
+ Status = AmdSevMemoryAccept (
+ NULL,
+ Desc->BaseAddress,
+ Desc->Length
+ );
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+
+ Status = gDS->RemoveMemorySpace (Desc->BaseAddress, Desc->Length);
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+
+ Status = gDS->AddMemorySpace (
+ EfiGcdMemoryTypeSystemMemory,
+ Desc->BaseAddress,
+ Desc->Length,
+ EFI_MEMORY_CPU_CRYPTO | EFI_MEMORY_XP | EFI_MEMORY_RO | EFI_MEMORY_RP
+ );
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+ }
+
+ gBS->FreePool (AllDescMap);
+ return Status;
+}
+
+VOID
+EFIAPI
+ResolveUnacceptedMemory (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ EFI_STATUS Status;
+
+ if (!mAcceptAllMemoryAtEBS) {
+ return;
+ }
+
+ Status = AcceptAllMemory ();
+ ASSERT_EFI_ERROR (Status);
+}
+
STATIC EDKII_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = {
AmdSevMemoryAccept
};
@@ -195,6 +276,22 @@ AmdSevDxeEntryPoint ( );
ASSERT_EFI_ERROR (Status);
+ // SEV-SNP support does not automatically imply unaccepted memory support,
+ // so make ExitBootServices accept all unaccepted memory if support is
+ // not communicated.
+ Status = gBS->CreateEventEx (
+ EVT_NOTIFY_SIGNAL,
+ TPL_CALLBACK,
+ ResolveUnacceptedMemory,
+ NULL,
+ &gEfiEventBeforeExitBootServicesGuid,
+ &mAcceptAllMemoryEvent
+ );
+
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "AllowUnacceptedMemory event creation for EventBeforeExitBootServices failed.\n"));
+ }
+
//
// 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.
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf index cd1b686c53..5b443d45bc 100644 --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf @@ -52,6 +52,7 @@ [Guids]
gConfidentialComputingSevSnpBlobGuid
+ gEfiEventBeforeExitBootServicesGuid
[Pcd]
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
|