Hi On Thu, Mar 8, 2018 at 8:57 PM, Dr. David Alan Gilbert (git) <dgilb...@redhat.com> wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > Send requests back to the source for shared page requests. >
Well, you could update the commit message to say that it introduces a callback to be used in the following patches, as well as saving RB of last request. For now that patch does no functional change :) > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> > --- > migration/migration.h | 2 ++ > migration/postcopy-ram.c | 32 +++++++++++++++++++++++++++++--- > migration/postcopy-ram.h | 3 +++ > migration/trace-events | 2 ++ > 4 files changed, 36 insertions(+), 3 deletions(-) > > diff --git a/migration/migration.h b/migration/migration.h > index d02a759331..83dc36b57a 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -49,6 +49,8 @@ struct MigrationIncomingState { > int userfault_event_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 4ab1b7d36d..83780576ca 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -525,6 +525,32 @@ static int ram_block_enable_notify(const char > *block_name, void *host_addr, > return 0; > } > > +/* > + * 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 > */ > @@ -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 { > diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h > index c8ced3470b..d7afab07d7 100644 > --- a/migration/postcopy-ram.h > +++ b/migration/postcopy-ram.h > @@ -164,5 +164,8 @@ 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 1e617ad7a6..7c910b5479 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -198,6 +198,8 @@ 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 0x%"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" > -- > 2.14.3 > > -- Marc-André Lureau