kvm: add memory encryption context

Split from a patch by Brijesh Singh (brijesh.singh@amd.com).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>

accel/Makefile.objs

@@ -1,4 +1,4 @@
 obj-$(CONFIG_SOFTMMU) += accel.o
-obj-y += kvm/
+obj-$(CONFIG_KVM) += kvm/
 obj-$(CONFIG_TCG) += tcg/
 obj-y += stubs/

accel/kvm/Makefile.objs

@@ -1 +1,2 @@
-obj-$(CONFIG_KVM) += kvm-all.o
+obj-y += kvm-all.o
+obj-$(call lnot,$(CONFIG_SEV)) += sev-stub.o

accel/kvm/kvm-all.c

@@ -38,6 +38,7 @@
 #include "qemu/event_notifier.h"
 #include "trace.h"
 #include "hw/irq.h"
+#include "sysemu/sev.h"
 
 #include "hw/boards.h"
 
@@ -103,6 +104,9 @@ struct KVMState
 #endif
     KVMMemoryListener memory_listener;
     QLIST_HEAD(, KVMParkedVcpu) kvm_parked_vcpus;
+
+    /* memory encryption */
+    void *memcrypt_handle;
 };
 
 KVMState *kvm_state;
@@ -138,6 +142,15 @@ int kvm_get_max_memslots(void)
     return s->nr_slots;
 }
 
+bool kvm_memcrypt_enabled(void)
+{
+    if (kvm_state && kvm_state->memcrypt_handle) {
+        return true;
+    }
+
+    return false;
+}
+
 static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
 {
     KVMState *s = kvm_state;
@@ -1636,6 +1649,18 @@ static int kvm_init(MachineState *ms)
 
     kvm_state = s;
 
+    /*
+     * if memory encryption object is specified then initialize the memory
+     * encryption context.
+     */
+    if (ms->memory_encryption) {
+        kvm_state->memcrypt_handle = sev_guest_init(ms->memory_encryption);
+        if (!kvm_state->memcrypt_handle) {
+            ret = -1;
+            goto err;
+        }
+    }
+
     ret = kvm_arch_init(ms, s);
     if (ret < 0) {
         goto err;

accel/kvm/sev-stub.c

@@ -0,0 +1,21 @@
+/*
+ * QEMU SEV stub
+ *
+ * Copyright Advanced Micro Devices 2018
+ *
+ * Authors:
+ *      Brijesh Singh <brijesh.singh@amd.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "sysemu/sev.h"
+
+void *sev_guest_init(const char *id)
+{
+    return NULL;
+}

accel/stubs/kvm-stub.c

@@ -105,6 +105,11 @@ int kvm_on_sigbus(int code, void *addr)
     return 1;
 }
 
+bool kvm_memcrypt_enabled(void)
+{
+    return false;
+}
+
 #ifndef CONFIG_USER_ONLY
 int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {

include/sysemu/kvm.h

@@ -231,6 +231,15 @@ int kvm_destroy_vcpu(CPUState *cpu);
  */
 bool kvm_arm_supports_user_irq(void);
 
+/**
+ * kvm_memcrypt_enabled - return boolean indicating whether memory encryption
+ *                        is enabled
+ * Returns: 1 memory encryption is enabled
+ *          0 memory encryption is disabled
+ */
+bool kvm_memcrypt_enabled(void);
+
+
 #ifdef NEED_CPU_H
 #include "cpu.h"
 

include/sysemu/sev.h

@@ -0,0 +1,20 @@
+/*
+ * QEMU Secure Encrypted Virutualization (SEV) support
+ *
+ * Copyright: Advanced Micro Devices, 2016-2018
+ *
+ * Authors:
+ *  Brijesh Singh <brijesh.singh@amd.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_SEV_H
+#define QEMU_SEV_H
+
+#include "sysemu/kvm.h"
+
+void *sev_guest_init(const char *id);
+#endif