From e2b3943bf75d34f5e913e05fbdf8116179812866 Mon Sep 17 00:00:00 2001
From: fangbaoshun <fangbaoshun@hygon.cn>
Date: Mon, 2 Aug 2021 14:35:51 +0800
Subject: [PATCH] migration/ram: Accelerate the transmission of CSV guest's
 encrypted pages

When memory encryption is enabled, the guest memory will be encrypted with
the guest specific key. The patch introduces an accelerate solution which
queued the pages into list and send them togather by COMMAND_BATCH.

Signed-off-by: hanliyang <hanliyang@hygon.cn>
---
 configs/devices/i386-softmmu/default.mak |   1 +
 hw/i386/Kconfig                          |   5 +
 migration/ram.c                          | 119 +++++++++++++++++++++++
 target/i386/csv.h                        |   2 +
 4 files changed, 127 insertions(+)

diff --git a/configs/devices/i386-softmmu/default.mak b/configs/devices/i386-softmmu/default.mak
index db83ffcab9..e948e54e4e 100644
--- a/configs/devices/i386-softmmu/default.mak
+++ b/configs/devices/i386-softmmu/default.mak
@@ -24,6 +24,7 @@
 #CONFIG_VTD=n
 #CONFIG_SGX=n
 #CONFIG_CSV=n
+#CONFIG_HYGON_CSV_MIG_ACCEL=n
 
 # Boards:
 #
diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index 08f3ae43f8..682e324f1c 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -12,8 +12,13 @@ config SGX
 
 config CSV
     bool
+    select HYGON_CSV_MIG_ACCEL
     depends on SEV
 
+config HYGON_CSV_MIG_ACCEL
+    bool
+    depends on CSV
+
 config PC
     bool
     imply APPLESMC
diff --git a/migration/ram.c b/migration/ram.c
index 1abe8476f7..7747f5af3a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -67,6 +67,7 @@
 
 /* Defines RAM_SAVE_ENCRYPTED_PAGE and RAM_SAVE_SHARED_REGION_LIST */
 #include "target/i386/sev.h"
+#include "target/i386/csv.h"
 #include "sysemu/kvm.h"
 
 #include "hw/boards.h" /* for machine_dump_guest_core() */
@@ -2336,6 +2337,112 @@ out:
     return ret;
 }
 
+#ifdef CONFIG_HYGON_CSV_MIG_ACCEL
+/**
+ * ram_save_encrypted_pages_in_batch: send the given encrypted pages to
+ *                                    the stream.
+ *
+ * Sending pages of 4K size in batch. The saving stops at the end of
+ * the block.
+ *
+ * The caller must be with ram_state.bitmap_mutex held to call this
+ * function.
+ *
+ * Returns the number of pages written or negative on error
+ *
+ * @rs: current RAM state
+ * @pss: data about the page we want to send
+ */
+static int
+ram_save_encrypted_pages_in_batch(RAMState *rs, PageSearchStatus *pss)
+{
+    bool page_dirty;
+    int ret;
+    int tmppages, pages = 0;
+    uint8_t *p;
+    uint32_t host_len = 0;
+    uint64_t bytes_xmit = 0;
+    ram_addr_t offset, start_offset = 0;
+    MachineState *ms = MACHINE(qdev_get_machine());
+    ConfidentialGuestSupportClass *cgs_class =
+        (ConfidentialGuestSupportClass *)object_get_class(OBJECT(ms->cgs));
+    struct ConfidentialGuestMemoryEncryptionOps *ops =
+        cgs_class->memory_encryption_ops;
+
+    do {
+        page_dirty = migration_bitmap_clear_dirty(rs, pss->block, pss->page);
+
+        /* Check the pages is dirty and if it is send it */
+        if (page_dirty) {
+            /* Process the unencrypted page */
+            if (!encrypted_test_list(rs, pss->block, pss->page)) {
+                tmppages = migration_ops->ram_save_target_page(rs, pss);
+            } else {
+                /* Caculate the offset and host virtual address of the page */
+                offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
+                p = pss->block->host + offset;
+
+                /* Record the offset and host virtual address of the first
+                 * page in this loop which will be used below.
+                 */
+                if (host_len == 0) {
+                    start_offset = offset | RAM_SAVE_FLAG_ENCRYPTED_DATA;
+                } else {
+                    offset |= (RAM_SAVE_FLAG_ENCRYPTED_DATA | RAM_SAVE_FLAG_CONTINUE);
+                }
+
+                /* Queue the outgoing page if the page is not zero page.
+                 * If the queued pages are up to the outgoing page window size,
+                 * process them below.
+                 */
+                if (ops->queue_outgoing_page(p, TARGET_PAGE_SIZE, offset))
+                    return -1;
+
+                tmppages = 1;
+                host_len += TARGET_PAGE_SIZE;
+
+                stat64_add(&mig_stats.normal_pages, 1);
+            }
+        } else {
+            tmppages = 0;
+        }
+
+        if (tmppages >= 0) {
+            pages += tmppages;
+        } else {
+            return tmppages;
+        }
+
+        pss_find_next_dirty(pss);
+    } while (offset_in_ramblock(pss->block,
+                                ((ram_addr_t)pss->page) << TARGET_PAGE_BITS) &&
+             host_len < CSV_OUTGOING_PAGE_WINDOW_SIZE);
+
+    /* Check if there are any queued pages */
+    if (host_len != 0) {
+        ram_transferred_add(save_page_header(pss, pss->pss_channel,
+                                             pss->block, start_offset));
+        /* if only one page queued, flag is BATCH_END, else flag is BATCH */
+        if (host_len > TARGET_PAGE_SIZE)
+            qemu_put_be32(pss->pss_channel, RAM_SAVE_ENCRYPTED_PAGE_BATCH);
+        else
+            qemu_put_be32(pss->pss_channel, RAM_SAVE_ENCRYPTED_PAGE_BATCH_END);
+        ram_transferred_add(4);
+        /* Process the queued pages in batch */
+        ret = ops->save_queued_outgoing_pages(pss->pss_channel, &bytes_xmit);
+        if (ret) {
+            return -1;
+        }
+        ram_transferred_add(bytes_xmit);
+    }
+
+    /* The offset we leave with is the last one we looked at */
+    pss->page--;
+
+    return pages;
+}
+#endif
+
 /**
  * ram_save_host_page: save a whole host page
  *
@@ -2371,6 +2478,18 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss)
         return 0;
     }
 
+#ifdef CONFIG_HYGON_CSV_MIG_ACCEL
+    /*
+     * If command_batch function is enabled and memory encryption is enabled
+     * then use command batch APIs to accelerate the sending process
+     * to write the outgoing buffer to the wire. The encryption APIs
+     * will re-encrypt the data with transport key so that data is prototect
+     * on the wire.
+     */
+    if (memcrypt_enabled() && is_hygon_cpu() && !migration_in_postcopy())
+        return ram_save_encrypted_pages_in_batch(rs, pss);
+#endif
+
     /* Update host page boundary information */
     pss_host_page_prepare(pss);
 
diff --git a/target/i386/csv.h b/target/i386/csv.h
index 977f08b982..74a54f9b9c 100644
--- a/target/i386/csv.h
+++ b/target/i386/csv.h
@@ -44,6 +44,8 @@ static bool __attribute__((unused)) is_hygon_cpu(void)
 
 #endif
 
+#define CSV_OUTGOING_PAGE_WINDOW_SIZE     (4094 * TARGET_PAGE_SIZE)
+
 typedef struct CsvBatchCmdList CsvBatchCmdList;
 typedef void (*CsvDestroyCmdNodeFn) (void *data);
 
-- 
2.41.0.windows.1