[Qemu-devel] [PATCH v6 12/23] kvm: introduce memory encryption APIs

[Brijesh Singh <brijesh.singh@amd.com>]

Inorder to integerate the Secure Encryption Virtualization (SEV) support
add few high-level memory encryption APIs which can be used for encrypting
the guest memory region.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 accel/kvm/kvm-all.c    | 30 ++++++++++++++++++++++++++++++
 accel/stubs/kvm-stub.c | 14 ++++++++++++++
 include/sysemu/kvm.h   | 25 +++++++++++++++++++++++++
 3 files changed, 69 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index a9b16846675e..54a0fd6097fb 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -107,6 +107,8 @@ struct KVMState
 
     /* memory encryption */
     void *memcrypt_handle;
+    int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len);
+    void (*memcrypt_debug_ops)(void *handle, MemoryRegion *mr);
 };
 
 KVMState *kvm_state;
@@ -142,6 +144,34 @@ 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;
+}
+
+int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len)
+{
+    if (kvm_state->memcrypt_handle &&
+        kvm_state->memcrypt_encrypt_data) {
+        return kvm_state->memcrypt_encrypt_data(kvm_state->memcrypt_handle,
+                                              ptr, len);
+    }
+
+    return 1;
+}
+
+void kvm_memcrypt_set_debug_ops(MemoryRegion *mr)
+{
+    if (kvm_state->memcrypt_handle &&
+        kvm_state->memcrypt_debug_ops) {
+        kvm_state->memcrypt_debug_ops(kvm_state->memcrypt_handle, mr);
+    }
+}
+
 static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
 {
     KVMState *s = kvm_state;
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index c964af3e1c97..5739712a67e3 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -105,6 +105,20 @@ int kvm_on_sigbus(int code, void *addr)
     return 1;
 }
 
+bool kvm_memcrypt_enabled(void)
+{
+    return false;
+}
+
+int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len)
+{
+  return 1;
+}
+
+void kvm_memcrypt_set_debug_ops(MemoryRegion *mr)
+{
+}
+
 #ifndef CONFIG_USER_ONLY
 int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index bbf12a172339..4a5db5dde390 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -231,6 +231,31 @@ 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);
+
+/**
+ * kvm_memcrypt_encrypt_data: encrypt the memory range
+ *
+ * Return: 1 failed to encrypt the range
+ *         0 succesfully encrypted memory region
+ */
+int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len);
+
+/**
+ * kvm_memcrypt_set_debug_ram_ops: set debug_ram_ops callback
+ *
+ * When debug_ram_ops is set, debug access to this memory region will use
+ * memory encryption APIs.
+ */
+void kvm_memcrypt_set_debug_ops(MemoryRegion *mr);
+
+
 #ifdef NEED_CPU_H
 #include "cpu.h"
 
-- 
2.9.5