From 096bf4c8522fc0331fef78e46108244ab09480a0 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 12 Mar 2018 17:21:12 +0000 Subject: vhost+postcopy: Helper to send requests to source for shared pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- 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(-) (limited to 'migration') 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 6ce157741f..146bc09c17 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" -- cgit v1.2.1