[Qemu-devel] [PATCH v2 11/13] kvm: introduce high-level API to migrate the page encryption bitmap

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

Encrypted VMs have concept of private and shared memory. The private
memory is encrypted with the guest-specific key, while shared memory
may be encrypted with hyperivosr key. The guest OS uses a hypercall
to notify the page encryption state to the hypervisor. The hypervisor
maintain a bitmap of page encryption state. This bitmap should be
migrated to ensure that target machine can function correctly.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 accel/kvm/kvm-all.c    | 37 +++++++++++++++++++++++++++++++++++++
 accel/kvm/sev-stub.c   | 11 +++++++++++
 accel/stubs/kvm-stub.c | 10 ++++++++++
 include/sysemu/kvm.h   | 13 +++++++++++++
 include/sysemu/sev.h   |  3 +++
 5 files changed, 74 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 7f94dba6f9..442b1af36e 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -114,6 +114,9 @@ struct KVMState
             uint8_t *ptr, uint32_t sz, uint64_t *bytes_sent);
     int (*memcrypt_load_incoming_page)(void *ehandle, QEMUFile *f,
             uint8_t *ptr);
+    int (*memcrypt_load_incoming_page_enc_bitmap)(void *ehandle, QEMUFile *f);
+    int (*memcrypt_save_outgoing_page_enc_bitmap)(void *ehandle, QEMUFile *f,
+            uint64_t start, uint64_t length);
 };
 
 KVMState *kvm_state;
@@ -192,6 +195,40 @@ int kvm_memcrypt_load_incoming_page(QEMUFile *f, uint8_t *ptr)
     return 1;
 }
 
+int kvm_memcrypt_load_incoming_page_enc_bitmap(QEMUFile *f)
+{
+    if (kvm_state->memcrypt_handle &&
+        kvm_state->memcrypt_load_incoming_page_enc_bitmap) {
+        return kvm_state->memcrypt_load_incoming_page_enc_bitmap(
+                kvm_state->memcrypt_handle, f);
+    }
+
+    return 1;
+}
+
+int kvm_memcrypt_save_outgoing_page_enc_bitmap(QEMUFile *f)
+{
+    KVMMemoryListener *kml = &kvm_state->memory_listener;
+    KVMState *s = kvm_state;
+    int ret = 1, i;
+
+    if (s->memcrypt_handle &&
+        s->memcrypt_save_outgoing_page_enc_bitmap) {
+
+        /* iterate through all the registered slots and send the bitmap */
+        for (i = 0; i < s->nr_slots; i++) {
+            KVMSlot *mem = &kml->slots[i];
+            ret = s->memcrypt_save_outgoing_page_enc_bitmap(s->memcrypt_handle,
+                        f, mem->start_addr, mem->memory_size);
+            if (ret) {
+                return 1;
+            }
+        }
+    }
+
+    return ret;
+}
+
 static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
 {
     KVMState *s = kvm_state;
diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c
index c12a8e005e..7acd7211e6 100644
--- a/accel/kvm/sev-stub.c
+++ b/accel/kvm/sev-stub.c
@@ -35,3 +35,14 @@ int sev_load_incoming_page(void *handle, QEMUFile *f, uint8_t *ptr)
 {
     return 1;
 }
+
+int sev_load_incoming_page_enc_bitmap(void *handle, QEMUFile *f)
+{
+    return 1;
+}
+
+int sev_save_outgoing_page_enc_bitmap(void *handle, QEMUFile *f,
+                                      uint64_t start, uint64_t length)
+{
+    return 1;
+}
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index e14b879531..ae607787e7 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -125,6 +125,16 @@ int kvm_memcrypt_load_incoming_page(QEMUFile *f, uint8_t *ptr)
     return 1;
 }
 
+int kvm_memcrypt_load_incoming_page_enc_bitmap(QEMUFile *f)
+{
+    return 1;
+}
+
+int kvm_memcrypt_save_outgoing_page_enc_bitmap(QEMUFile *f)
+{
+    return 1;
+}
+
 
 #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 bb6bcc143c..8aa06b4462 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -260,6 +260,19 @@ int kvm_memcrypt_save_outgoing_page(QEMUFile *f, uint8_t *ptr, uint32_t size,
  */
 int kvm_memcrypt_load_incoming_page(QEMUFile *f, uint8_t *ptr);
 
+/**
+ * kvm_memcrypt_load_incoming_page_enc_bitmap: read the page encryption bitmap
+ * from the socket and pass it to the hypervisor.
+ */
+int kvm_memcrypt_load_incoming_page_enc_bitmap(QEMUFile *f);
+
+/**
+ * kvm_memcrypt_save_outgoing_page_enc_bitmap: write the page encryption bitmap
+ * on socket.
+ */
+int kvm_memcrypt_save_outgoing_page_enc_bitmap(QEMUFile *f);
+
+
 #ifdef NEED_CPU_H
 #include "cpu.h"
 
diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 752a71b1c0..e08886ca33 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -21,4 +21,7 @@ int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len);
 int sev_save_outgoing_page(void *handle, QEMUFile *f, uint8_t *ptr,
                            uint32_t size, uint64_t *bytes_sent);
 int sev_load_incoming_page(void *handle, QEMUFile *f, uint8_t *ptr);
+int sev_load_incoming_page_enc_bitmap(void *handle, QEMUFile *f);
+int sev_save_outgoing_page_enc_bitmap(void *handle, QEMUFile *f,
+                                      uint64_t start, uint64_t length);
 #endif
-- 
2.17.1