diff --git a/OvmfPkg/Include/Guid/OvmfPkKek1AppPrefix.h b/OvmfPkg/Include/Guid/OvmfPkKek1AppPrefix.h
new file mode 100644
index 0000000000..e05d2fe021
--- /dev/null
+++ b/OvmfPkg/Include/Guid/OvmfPkKek1AppPrefix.h
@@ -0,0 +1,45 @@
+/** @file
+  Declare the application prefix string as a GUID, for locating the PK/KEK1
+  X509 certificate to enroll, in the "OEM Strings" SMBIOS table.
+
+  Copyright (C) 2019, Red Hat, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Specification Reference:
+  - https://git.qemu.org/?p=qemu.git;a=commit;h=2d6dcbf93fb0
+  - https://libvirt.org/formatdomain.html#elementsSysinfo
+  - https://bugs.launchpad.net/qemu/+bug/1826200
+  - https://bugzilla.tianocore.org/show_bug.cgi?id=1747
+**/
+
+#ifndef OVMF_PK_KEK1_APP_PREFIX_H_
+#define OVMF_PK_KEK1_APP_PREFIX_H_
+
+#include <Uefi/UefiBaseType.h>
+
+//
+// For the EnrollDefaultKeys application, the hypervisor is expected to add a
+// string entry to the "OEM Strings" (Type 11) SMBIOS table, with the following
+// format:
+//
+// 4e32566d-8e9e-4f52-81d3-5bb9715f9727:<Base64 X509 cert for PK and first KEK>
+//
+// The string representation of the GUID at the front is the "application
+// prefix". It is matched by EnrollDefaultKeys case-insensitively.
+//
+// The base64-encoded blob following the application prefix and the colon (:)
+// is an X509 certificate in DER representation; the hypervisor instructs
+// EnrollDefaultKeys to enroll this certificate as both Platform Key and first
+// Key Exchange Key.
+//
+#define OVMF_PK_KEK1_APP_PREFIX_GUID                    \
+  { 0x4e32566d,                                         \
+    0x8e9e,                                             \
+    0x4f52,                                             \
+    { 0x81, 0xd3, 0x5b, 0xb9, 0x71, 0x5f, 0x97, 0x27 }, \
+  }
+
+extern EFI_GUID gOvmfPkKek1AppPrefixGuid;
+
+#endif /* OVMF_PK_KEK1_APP_PREFIX_H_ */
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 922e061cc8..0e555c5c78 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -72,6 +72,7 @@
 [Guids]
   gUefiOvmfPkgTokenSpaceGuid          = {0x93bb96af, 0xb9f2, 0x4eb8, {0x94, 0x62, 0xe0, 0xba, 0x74, 0x56, 0x42, 0x36}}
   gEfiXenInfoGuid                     = {0xd3b46f3b, 0xd441, 0x1244, {0x9a, 0x12, 0x0, 0x12, 0x27, 0x3f, 0xc1, 0x4d}}
+  gOvmfPkKek1AppPrefixGuid            = {0x4e32566d, 0x8e9e, 0x4f52, {0x81, 0xd3, 0x5b, 0xb9, 0x71, 0x5f, 0x97, 0x27}}
   gOvmfPlatformConfigGuid             = {0x7235c51c, 0x0c80, 0x4cab, {0x87, 0xac, 0x3b, 0x08, 0x4a, 0x63, 0x04, 0xb1}}
   gVirtioMmioTransportGuid            = {0x837dca9e, 0xe874, 0x4d82, {0xb2, 0x9a, 0x23, 0xfe, 0x0e, 0x23, 0xd1, 0xe2}}
   gQemuRamfbGuid                      = {0x557423a1, 0x63ab, 0x406c, {0xbe, 0x7e, 0x91, 0xcd, 0xbc, 0x08, 0xc4, 0x57}}