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authorDr. David Alan Gilbert <dgilbert@redhat.com>2018-03-12 17:21:12 +0000
committerMichael S. Tsirkin <mst@redhat.com>2018-03-20 05:03:29 +0200
commit096bf4c8522fc0331fef78e46108244ab09480a0 (patch)
tree779b7a95305e128f6084da925a1e6082815d5bfb /migration/postcopy-ram.c
parent905125d0e20395188a090c16d38e38694fc43fc4 (diff)
downloadqemu-096bf4c8522fc0331fef78e46108244ab09480a0.zip
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vhost+postcopy: Helper to send requests to source for shared pages
Provide a helper to be used by shared waker functions to request shared pages from the source. The last_rb pointer is moved into the incoming state since this helper can update it as well as the main fault thread function. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'migration/postcopy-ram.c')
-rw-r--r--migration/postcopy-ram.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 6ce1577..146bc09 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -526,6 +526,32 @@ 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
+ * Note: Only for use by shared fault handlers (in fault thread)
+ */
+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)
@@ -535,9 +561,9 @@ 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;
@@ -636,8 +662,8 @@ 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 {