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authorDr. David Alan Gilbert <dgilbert@redhat.com>2018-03-12 17:21:14 +0000
committerMichael S. Tsirkin <mst@redhat.com>2018-03-20 16:40:35 +0200
commit5efc35640359c808746ce28a44262020b523abeb (patch)
treecead20329eb5ee318d587bd542c3e44be1cc0082 /migration
parent375318d03f3f3fca72606eea71240cb6a3536314 (diff)
postcopy: helper for waking shared
Provide a helper to send a 'wake' request on a userfaultfd for a shared process. The address in the clients address space is specified together with the RAMBlock it was resolved to. 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')
-rw-r--r--migration/postcopy-ram.c26
-rw-r--r--migration/postcopy-ram.h10
-rw-r--r--migration/trace-events1
3 files changed, 37 insertions, 0 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 8e08ff92f3..868f77b34d 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -525,6 +525,25 @@ static int ram_block_enable_notify(const char *block_name, void *host_addr,
return 0;
}
+int postcopy_wake_shared(struct PostCopyFD *pcfd,
+ uint64_t client_addr,
+ RAMBlock *rb)
+{
+ size_t pagesize = qemu_ram_pagesize(rb);
+ struct uffdio_range range;
+ int ret;
+ trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
+ range.start = client_addr & ~(pagesize - 1);
+ range.len = pagesize;
+ ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
+ if (ret) {
+ error_report("%s: Failed to wake: %zx in %s (%s)",
+ __func__, (size_t)client_addr, qemu_ram_get_idstr(rb),
+ strerror(errno));
+ }
+ return ret;
+}
+
/*
* Callback from shared fault handlers to ask for a page,
* the page must be specified by a RAMBlock and an offset in that rb
@@ -961,6 +980,13 @@ void *postcopy_get_tmp_page(MigrationIncomingState *mis)
return NULL;
}
+int postcopy_wake_shared(struct PostCopyFD *pcfd,
+ uint64_t client_addr,
+ RAMBlock *rb)
+{
+ assert(0);
+ return -1;
+}
#endif
/* ------------------------------------------------------------------------- */
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index d7afab07d7..fcd53b8295 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -164,6 +164,16 @@ struct PostCopyFD {
*/
void postcopy_register_shared_ufd(struct PostCopyFD *pcfd);
void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd);
+/* postcopy_wake_shared: Notify a client ufd that a page is available
+ *
+ * Returns 0 on success
+ *
+ * @pcfd: Structure with fd, handler and name as above
+ * @client_addr: Address in the client program, not QEMU
+ * @rb: The RAMBlock the page is in
+ */
+int postcopy_wake_shared(struct PostCopyFD *pcfd, uint64_t client_addr,
+ RAMBlock *rb);
/* 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);
diff --git a/migration/trace-events b/migration/trace-events
index 7c910b5479..b0acaaa8a0 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -199,6 +199,7 @@ 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 0x%"PRIx64
+postcopy_wake_shared(uint64_t client_addr, const char *rb) "at 0x%"PRIx64" in %s"
save_xbzrle_page_skipping(void) ""
save_xbzrle_page_overflow(void) ""