From 0f85e3a486c2d0130cb3be322900aa839d77d4bd Mon Sep 17 00:00:00 2001
From: Brijesh Singh <brijesh.singh@amd.com>
Date: Tue, 27 Jul 2021 16:31:36 +0000
Subject: [PATCH] migration: add support to migrate shared regions list

cherry-picked from https://github.com/AMDESE/qemu/commit/9236f522e48b6.

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>
[ Fix conflicts. ]
Signed-off-by: hanliyang <hanliyang@hygon.cn>
---
 include/exec/confidential-guest-support.h |  2 +-
 target/i386/sev.c                         | 45 +++++++++++++++++++++++
 target/i386/sev.h                         |  2 +
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h
index 343f686fc2..dd4887f65f 100644
--- a/include/exec/confidential-guest-support.h
+++ b/include/exec/confidential-guest-support.h
@@ -73,7 +73,7 @@ struct ConfidentialGuestMemoryEncryptionOps {
     bool (*is_gfn_in_unshared_region)(unsigned long gfn);
 
     /* Write the shared regions list */
-    int (*save_outgoing_shared_regions_list)(QEMUFile *f);
+    int (*save_outgoing_shared_regions_list)(QEMUFile *f, uint64_t *bytes_sent);
 
     /* Load the shared regions list */
     int (*load_incoming_shared_regions_list)(QEMUFile *f);
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 8525a7351f..92aedf0503 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -176,10 +176,15 @@ 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
@@ -1777,6 +1782,46 @@ int sev_add_shared_regions_list(unsigned long start, unsigned long end)
     return 1;
 }
 
+int sev_save_outgoing_shared_regions_list(QEMUFile *f, uint64_t *bytes_sent)
+{
+    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);
+        *bytes_sent += 12;
+    }
+
+    qemu_put_be32(f, SHARED_REGION_LIST_END);
+    *bytes_sent += 4;
+    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 const QemuUUID sev_hash_table_header_guid = {
     .data = UUID_LE(0x9438d606, 0x4f22, 0x4cc9, 0xb4, 0x79, 0xa7, 0x93,
                     0xd4, 0x11, 0xfd, 0x21)
diff --git a/target/i386/sev.h b/target/i386/sev.h
index acf69d4e6f..5b4231c859 100644
--- a/target/i386/sev.h
+++ b/target/i386/sev.h
@@ -64,6 +64,8 @@ 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, uint64_t *bytes_sent);
+int sev_load_incoming_shared_regions_list(QEMUFile *f);
 
 int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp);
 
-- 
2.41.0.windows.1