From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
Send requests back to the source for shared page requests.
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
migration/migration.h | 2 ++
migration/postcopy-ram.c | 31 ++++++++++++++++++++++++++++---
migration/postcopy-ram.h | 3 +++
migration/trace-events | 2 ++
4 files changed, 35 insertions(+), 3 deletions(-)
diff --git a/migration/migration.h b/migration/migration.h
index 1210b217a1..5fa0bb7b53 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -49,6 +49,8 @@ struct MigrationIncomingState {
int userfault_quit_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
+ /* RAMBlock of last request sent to source */
+ RAMBlock *last_rb;
void *postcopy_tmp_page;
void *postcopy_tmp_zero_page;
/* PostCopyFD's for external userfaultfds & handlers of shared memory */
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index d43a73c108..cbf10236f0 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -460,6 +460,31 @@ static int ram_block_enable_notify(const char *block_name,
void *host_addr,
}
/*
+ * Callback from shared fault handlers to ask for a page,
+ * the page must be specified by a RAMBlock and an offset in that rb
+ */
+int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
+ uint64_t client_addr, uint64_t rb_offset)
+{
+ size_t pagesize = qemu_ram_pagesize(rb);
+ uint64_t aligned_rbo = rb_offset & ~(pagesize - 1);
+ MigrationIncomingState *mis = migration_incoming_get_current();
+
+ trace_postcopy_request_shared_page(pcfd->idstr, qemu_ram_get_idstr(rb),
+ rb_offset);
+ /* TODO: Check bitmap to see if we already have the page */
+ if (rb != mis->last_rb) {
+ mis->last_rb = rb;
+ migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
+ aligned_rbo, pagesize);
+ } else {
+ /* Save some space */
+ migrate_send_rp_req_pages(mis, NULL, aligned_rbo, pagesize);
+ }
+ return 0;
+}
+
+/*
* Handle faults detected by the USERFAULT markings
*/
static void *postcopy_ram_fault_thread(void *opaque)
@@ -469,9 +494,9 @@ static void *postcopy_ram_fault_thread(void *opaque)
int ret;
size_t index;
RAMBlock *rb = NULL;
- RAMBlock *last_rb = NULL; /* last RAMBlock we sent part of */
trace_postcopy_ram_fault_thread_entry();
+ mis->last_rb = NULL; /* last RAMBlock we sent part of */
qemu_sem_post(&mis->fault_thread_sem);
struct pollfd *pfd;
@@ -560,8 +585,8 @@ static void *postcopy_ram_fault_thread(void *opaque)
* Send the request to the source - we want to request one
* of our host page sizes (which is >= TPS)
*/
- if (rb != last_rb) {
- last_rb = rb;
+ if (rb != mis->last_rb) {
+ mis->last_rb = rb;
migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
rb_offset, qemu_ram_pagesize(rb));
} else {
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 873c147b68..69e88b0174 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -162,5 +162,8 @@ struct PostCopyFD {
*/
void postcopy_register_shared_ufd(struct PostCopyFD *pcfd);
void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd);
+/* Callback from shared fault handlers to ask for a page */
+int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
+ uint64_t client_addr, uint64_t offset);
#endif
diff --git a/migration/trace-events b/migration/trace-events
index 522cfa170d..7ac8f9cf41 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -197,6 +197,8 @@ postcopy_ram_incoming_cleanup_closeuf(void) ""
postcopy_ram_incoming_cleanup_entry(void) ""
postcopy_ram_incoming_cleanup_exit(void) ""
postcopy_ram_incoming_cleanup_join(void) ""
+postcopy_request_shared_page(const char *sharer, const char *rb, uint64_t
rb_offset) "for %s in %s offset %"PRIx64
+
save_xbzrle_page_skipping(void) ""
save_xbzrle_page_overflow(void) ""
ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: %"
PRIu64 " milliseconds, %d iterations"
--
2.13.0
