From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
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 <dgilb...@redhat.com>
---
migration/postcopy-ram.c | 26 ++++++++++++++++++++++++++
migration/postcopy-ram.h | 6 ++++++
migration/trace-events | 1 +
3 files changed, 33 insertions(+)
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 2d77674b94..2c9680ef7a 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -458,6 +458,25 @@ 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__, 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
@@ -876,6 +895,13 @@ 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 69e88b0174..d2b2f5f4aa 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -162,6 +162,12 @@ struct PostCopyFD {
*/
void postcopy_register_shared_ufd(struct PostCopyFD *pcfd);
void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd);
+/* Notify a client ufd that a page is available
+ * Note: The 'client_address' is in the address space of the client
+ * program not QEMU
+ */
+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 3a0b143f7e..535e7ad84b 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -198,6 +198,7 @@ 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) ""
--
2.13.5
