From 5efc35640359c808746ce28a44262020b523abeb Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 12 Mar 2018 17:21:14 +0000 Subject: postcopy: helper for waking shared MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- migration/postcopy-ram.c | 26 ++++++++++++++++++++++++++ migration/postcopy-ram.h | 10 ++++++++++ migration/trace-events | 1 + 3 files changed, 37 insertions(+) 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) "" -- cgit v1.2.1