X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=OvmfPkg%2FLibrary%2FBaseMemEncryptSevLib%2FMemEncryptSevLibInternal.c;fp=OvmfPkg%2FLibrary%2FBaseMemEncryptSevLib%2FMemEncryptSevLibInternal.c;h=002f079c7eb3910c0e6f81ed4ad25b8b766295ea;hp=0000000000000000000000000000000000000000;hb=a1f2261425d59e359df30e3a415933def9b7f435;hpb=97353a9c914d4bf53ad084689ade0675b71a5c48
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c b/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c
new file mode 100644
index 0000000000..002f079c7e
--- /dev/null
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c
@@ -0,0 +1,90 @@
+/** @file
+
+ Secure Encrypted Virtualization (SEV) library helper function
+
+ Copyright (c) 2017, AMD Incorporated. All rights reserved.
+
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD
+ License which accompanies this distribution. The full text of the license may
+ be found at http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include
+#include
+#include
+#include
+#include
+#include
+
+STATIC BOOLEAN mSevStatus = FALSE;
+STATIC BOOLEAN mSevStatusChecked = FALSE;
+
+/**
+
+ Returns a boolean to indicate whether SEV is enabled
+
+ @retval TRUE SEV is enabled
+ @retval FALSE SEV is not enabled
+ **/
+STATIC
+BOOLEAN
+EFIAPI
+InternalMemEncryptSevIsEnabled (
+ VOID
+ )
+{
+ UINT32 RegEax;
+ MSR_SEV_STATUS_REGISTER Msr;
+ CPUID_MEMORY_ENCRYPTION_INFO_EAX Eax;
+
+ //
+ // Check if memory encryption leaf exist
+ //
+ AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
+ if (RegEax >= CPUID_MEMORY_ENCRYPTION_INFO) {
+ //
+ // CPUID Fn8000_001F[EAX] Bit 1 (Sev supported)
+ //
+ AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, &Eax.Uint32, NULL, NULL, NULL);
+
+ if (Eax.Bits.SevBit) {
+ //
+ // Check MSR_0xC0010131 Bit 0 (Sev Enabled)
+ //
+ Msr.Uint32 = AsmReadMsr32 (MSR_SEV_STATUS);
+ if (Msr.Bits.SevBit) {
+ return TRUE;
+ }
+ }
+ }
+
+ return FALSE;
+}
+
+/**
+
+ Returns a boolean to indicate whether SEV is enabled
+
+ @retval TRUE SEV is enabled
+ @retval FALSE SEV is not enabled
+ **/
+BOOLEAN
+EFIAPI
+MemEncryptSevIsEnabled (
+ VOID
+ )
+{
+ if (mSevStatusChecked) {
+ return mSevStatus;
+ }
+
+ mSevStatus = InternalMemEncryptSevIsEnabled();
+ mSevStatusChecked = TRUE;
+
+ return mSevStatus;
+}