[PATCH v4 10/14] migration: add support to migrate shared regions list

[Ashish Kalra]

From: Brijesh Singh <brijesh.singh@amd.com>

When memory encryption is enabled, the hypervisor maintains a shared
regions list which is referred by hypervisor during migration to check
if page is private or shared. This list is built during the VM bootup and
must be migrated to the target host so that hypervisor on target host can
use it for future migration.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 include/sysemu/sev.h |  2 ++
 target/i386/sev.c    | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 3b913518c0..118ee66406 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -32,5 +32,7 @@ void sev_es_set_reset_vector(CPUState *cpu);
 int sev_remove_shared_regions_list(unsigned long gfn_start,
                                    unsigned long gfn_end);
 int sev_add_shared_regions_list(unsigned long gfn_start, unsigned long 
gfn_end);
+int sev_save_outgoing_shared_regions_list(QEMUFile *f);
+int sev_load_incoming_shared_regions_list(QEMUFile *f);
 
 #endif
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 6d44b7ad21..789051f7b4 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -135,10 +135,15 @@ static const char *const sev_fw_errlist[] = {
 
 #define SEV_FW_BLOB_MAX_SIZE            0x4000          /* 16KB */
 
+#define SHARED_REGION_LIST_CONT     0x1
+#define SHARED_REGION_LIST_END      0x2
+
 static struct ConfidentialGuestMemoryEncryptionOps sev_memory_encryption_ops = 
{
     .save_setup = sev_save_setup,
     .save_outgoing_page = sev_save_outgoing_page,
     .load_incoming_page = sev_load_incoming_page,
+    .save_outgoing_shared_regions_list = sev_save_outgoing_shared_regions_list,
+    .load_incoming_shared_regions_list = sev_load_incoming_shared_regions_list,
 };
 
 static int
@@ -1604,6 +1609,44 @@ int sev_add_shared_regions_list(unsigned long start, 
unsigned long end)
     return 1;
 }
 
+int sev_save_outgoing_shared_regions_list(QEMUFile *f)
+{
+    SevGuestState *s = sev_guest;
+    struct shared_region *pos;
+
+    QTAILQ_FOREACH(pos, &s->shared_regions_list, list) {
+        qemu_put_be32(f, SHARED_REGION_LIST_CONT);
+        qemu_put_be32(f, pos->gfn_start);
+        qemu_put_be32(f, pos->gfn_end);
+    }
+
+    qemu_put_be32(f, SHARED_REGION_LIST_END);
+    return 0;
+}
+
+int sev_load_incoming_shared_regions_list(QEMUFile *f)
+{
+    SevGuestState *s = sev_guest;
+    struct shared_region *shrd_region;
+    int status;
+
+    status = qemu_get_be32(f);
+    while (status == SHARED_REGION_LIST_CONT) {
+
+        shrd_region = g_malloc0(sizeof(*shrd_region));
+        if (!shrd_region) {
+            return 0;
+        }
+        shrd_region->gfn_start = qemu_get_be32(f);
+        shrd_region->gfn_end = qemu_get_be32(f);
+
+        QTAILQ_INSERT_TAIL(&s->shared_regions_list, shrd_region, list);
+
+        status = qemu_get_be32(f);
+    }
+    return 0;
+}
+
 static void
 sev_register_types(void)
 {
-- 
2.17.1