From 6d52c264fa9a7a78ee532f45d24704491ce4c431 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Wed, 1 Aug 2018 13:55:09 +0100
Subject: [PATCH 05/21] migration: introduce control_save_page()
RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20180801135522.11658-6-dgilbert@redhat.com>
Patchwork-id: 81581
O-Subject: [qemu-kvm RHEL8/virt212 PATCH 05/18] migration: introduce control_save_page()
Bugzilla: 1594384
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
From: Xiao Guangrong <xiaoguangrong@tencent.com>
Abstract the common function control_save_page() to cleanup the code,
no logic is changed
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180330075128.26919-6-xiaoguangrong@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 059ff0fb29dd3a56ac2843676915efc279938c6b)
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
migration/ram.c | 174 +++++++++++++++++++++++++++++---------------------------
1 file changed, 89 insertions(+), 85 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index cd6d98a..8dc98a5 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -975,6 +975,44 @@ static void ram_release_pages(const char *rbname, uint64_t offset, int pages)
ram_discard_range(rbname, offset, pages << TARGET_PAGE_BITS);
}
+/*
+ * @pages: the number of pages written by the control path,
+ * < 0 - error
+ * > 0 - number of pages written
+ *
+ * Return true if the pages has been saved, otherwise false is returned.
+ */
+static bool control_save_page(RAMState *rs, RAMBlock *block, ram_addr_t offset,
+ int *pages)
+{
+ uint64_t bytes_xmit = 0;
+ int ret;
+
+ *pages = -1;
+ ret = ram_control_save_page(rs->f, block->offset, offset, TARGET_PAGE_SIZE,
+ &bytes_xmit);
+ if (ret == RAM_SAVE_CONTROL_NOT_SUPP) {
+ return false;
+ }
+
+ if (bytes_xmit) {
+ ram_counters.transferred += bytes_xmit;
+ *pages = 1;
+ }
+
+ if (ret == RAM_SAVE_CONTROL_DELAYED) {
+ return true;
+ }
+
+ if (bytes_xmit > 0) {
+ ram_counters.normal++;
+ } else if (bytes_xmit == 0) {
+ ram_counters.duplicate++;
+ }
+
+ return true;
+}
+
/**
* ram_save_page: send the given page to the stream
*
@@ -991,56 +1029,36 @@ static void ram_release_pages(const char *rbname, uint64_t offset, int pages)
static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage)
{
int pages = -1;
- uint64_t bytes_xmit;
- ram_addr_t current_addr;
uint8_t *p;
- int ret;
bool send_async = true;
RAMBlock *block = pss->block;
ram_addr_t offset = pss->page << TARGET_PAGE_BITS;
+ ram_addr_t current_addr = block->offset + offset;
p = block->host + offset;
trace_ram_save_page(block->idstr, (uint64_t)offset, p);
- /* In doubt sent page as normal */
- bytes_xmit = 0;
- ret = ram_control_save_page(rs->f, block->offset,
- offset, TARGET_PAGE_SIZE, &bytes_xmit);
- if (bytes_xmit) {
- ram_counters.transferred += bytes_xmit;
- pages = 1;
+ if (control_save_page(rs, block, offset, &pages)) {
+ return pages;
}
XBZRLE_cache_lock();
-
- current_addr = block->offset + offset;
-
- if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
- if (ret != RAM_SAVE_CONTROL_DELAYED) {
- if (bytes_xmit > 0) {
- ram_counters.normal++;
- } else if (bytes_xmit == 0) {
- ram_counters.duplicate++;
- }
- }
- } else {
- pages = save_zero_page(rs, block, offset);
- if (pages > 0) {
- /* Must let xbzrle know, otherwise a previous (now 0'd) cached
- * page would be stale
+ pages = save_zero_page(rs, block, offset);
+ if (pages > 0) {
+ /* Must let xbzrle know, otherwise a previous (now 0'd) cached
+ * page would be stale
+ */
+ xbzrle_cache_zero_page(rs, current_addr);
+ ram_release_pages(block->idstr, offset, pages);
+ } else if (!rs->ram_bulk_stage &&
+ !migration_in_postcopy() && migrate_use_xbzrle()) {
+ pages = save_xbzrle_page(rs, &p, current_addr, block,
+ offset, last_stage);
+ if (!last_stage) {
+ /* Can't send this cached data async, since the cache page
+ * might get updated before it gets to the wire
*/
- xbzrle_cache_zero_page(rs, current_addr);
- ram_release_pages(block->idstr, offset, pages);
- } else if (!rs->ram_bulk_stage &&
- !migration_in_postcopy() && migrate_use_xbzrle()) {
- pages = save_xbzrle_page(rs, &p, current_addr, block,
- offset, last_stage);
- if (!last_stage) {
- /* Can't send this cached data async, since the cache page
- * might get updated before it gets to the wire
- */
- send_async = false;
- }
+ send_async = false;
}
}
@@ -1175,63 +1193,49 @@ static int ram_save_compressed_page(RAMState *rs, PageSearchStatus *pss,
bool last_stage)
{
int pages = -1;
- uint64_t bytes_xmit = 0;
uint8_t *p;
- int ret;
RAMBlock *block = pss->block;
ram_addr_t offset = pss->page << TARGET_PAGE_BITS;
p = block->host + offset;
- ret = ram_control_save_page(rs->f, block->offset,
- offset, TARGET_PAGE_SIZE, &bytes_xmit);
- if (bytes_xmit) {
- ram_counters.transferred += bytes_xmit;
- pages = 1;
+ if (control_save_page(rs, block, offset, &pages)) {
+ return pages;
}
- if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
- if (ret != RAM_SAVE_CONTROL_DELAYED) {
- if (bytes_xmit > 0) {
- ram_counters.normal++;
- } else if (bytes_xmit == 0) {
- ram_counters.duplicate++;
- }
+
+ /* When starting the process of a new block, the first page of
+ * the block should be sent out before other pages in the same
+ * block, and all the pages in last block should have been sent
+ * out, keeping this order is important, because the 'cont' flag
+ * is used to avoid resending the block name.
+ */
+ if (block != rs->last_sent_block) {
+ flush_compressed_data(rs);
+ pages = save_zero_page(rs, block, offset);
+ if (pages > 0) {
+ ram_release_pages(block->idstr, offset, pages);
+ } else {
+ /*
+ * Make sure the first page is sent out before other pages.
+ *
+ * we post it as normal page as compression will take much
+ * CPU resource.
+ */
+ ram_counters.transferred += save_page_header(rs, rs->f, block,
+ offset | RAM_SAVE_FLAG_PAGE);
+ qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE,
+ migrate_release_ram() &
+ migration_in_postcopy());
+ ram_counters.transferred += TARGET_PAGE_SIZE;
+ ram_counters.normal++;
+ pages = 1;
}
} else {
- /* When starting the process of a new block, the first page of
- * the block should be sent out before other pages in the same
- * block, and all the pages in last block should have been sent
- * out, keeping this order is important, because the 'cont' flag
- * is used to avoid resending the block name.
- */
- if (block != rs->last_sent_block) {
- flush_compressed_data(rs);
- pages = save_zero_page(rs, block, offset);
- if (pages > 0) {
- ram_release_pages(block->idstr, offset, pages);
- } else {
- /*
- * Make sure the first page is sent out before other pages.
- *
- * we post it as normal page as compression will take much
- * CPU resource.
- */
- ram_counters.transferred += save_page_header(rs, rs->f, block,
- offset | RAM_SAVE_FLAG_PAGE);
- qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE,
- migrate_release_ram() &
- migration_in_postcopy());
- ram_counters.transferred += TARGET_PAGE_SIZE;
- ram_counters.normal++;
- pages = 1;
- }
+ pages = save_zero_page(rs, block, offset);
+ if (pages == -1) {
+ pages = compress_page_with_multi_thread(rs, block, offset);
} else {
- pages = save_zero_page(rs, block, offset);
- if (pages == -1) {
- pages = compress_page_with_multi_thread(rs, block, offset);
- } else {
- ram_release_pages(block->idstr, offset, pages);
- }
+ ram_release_pages(block->idstr, offset, pages);
}
}
--
1.8.3.1