virtcontainers: define confidential guest framework

Define the structure and functions needed to support confidential
guests, this commit doesn't add support for any specific technology,
support for TDX, SEV, PEF and others will be added in following
commits.

Signed-off-by: Julio Montes <julio.montes@intel.com>

src/runtime/pkg/katautils/config.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2018 Intel Corporation
+// Copyright (c) 2018-2021 Intel Corporation
 // Copyright (c) 2018 HyperHQ Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
@@ -61,6 +61,12 @@ type tomlConfig struct {
 	Runtime    runtime
 	Factory    factory
 	Netmon     netmon
+	Image      image
+}
+
+type image struct {
+	ServiceOffload bool   `toml:"service_offload"`
+	Provision      string `toml:"provision"`
 }
 
 type factory struct {
@@ -130,6 +136,7 @@ type hypervisor struct {
 	HotplugVFIOOnRootBus    bool     `toml:"hotplug_vfio_on_root_bus"`
 	DisableVhostNet         bool     `toml:"disable_vhost_net"`
 	GuestMemoryDumpPaging   bool     `toml:"guest_memory_dump_paging"`
+	ConfidentialGuest       bool     `toml:"confidential_guest"`
 }
 
 type runtime struct {
@@ -702,6 +709,7 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		EnableAnnotations:       h.EnableAnnotations,
 		GuestMemoryDumpPath:     h.GuestMemoryDumpPath,
 		GuestMemoryDumpPaging:   h.GuestMemoryDumpPaging,
+		ConfidentialGuest:       h.ConfidentialGuest,
 	}, nil
 }
 
@@ -1055,6 +1063,7 @@ func GetDefaultHypervisorConfig() vc.HypervisorConfig {
 		RxRateLimiterMaxRate:    defaultRxRateLimiterMaxRate,
 		TxRateLimiterMaxRate:    defaultTxRateLimiterMaxRate,
 		SGXEPCSize:              defaultSGXEPCSize,
+		ConfidentialGuest:       defaultConfidentialGuest,
 	}
 }