From patchwork Mon Dec 2 09:19:12 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lei Li X-Patchwork-Id: 295840 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id CA5172C0098 for ; Mon, 2 Dec 2013 20:24:28 +1100 (EST) Received: from localhost ([::1]:34624 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VnPju-00053V-2l for incoming@patchwork.ozlabs.org; Mon, 02 Dec 2013 04:24:26 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48091) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VnPfk-0007HE-LK for qemu-devel@nongnu.org; Mon, 02 Dec 2013 04:20:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VnPfb-0002Wf-7b for qemu-devel@nongnu.org; Mon, 02 Dec 2013 04:20:08 -0500 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:37194) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VnPfa-0002WX-CL for qemu-devel@nongnu.org; Mon, 02 Dec 2013 04:19:59 -0500 Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 2 Dec 2013 14:49:55 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 0C0CB394003F for ; Mon, 2 Dec 2013 14:49:55 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rB29JoKc10027090 for ; Mon, 2 Dec 2013 14:49:50 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rB29JpjQ002257 for ; Mon, 2 Dec 2013 14:49:52 +0530 Received: from localhost.localdomain.cn.ibm.com ([9.115.122.11]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id rB29JI4w032476; Mon, 2 Dec 2013 14:49:49 +0530 From: Lei Li To: qemu-devel@nongnu.org Date: Mon, 2 Dec 2013 17:19:12 +0800 Message-Id: <1385975957-22941-13-git-send-email-lilei@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1385975957-22941-1-git-send-email-lilei@linux.vnet.ibm.com> References: <1385975957-22941-1-git-send-email-lilei@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13120209-8256-0000-0000-00000A61D329 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 122.248.162.5 Cc: aarcange@redhat.com, Lei Li , quintela@redhat.com, mrhines@linux.vnet.ibm.com, aliguori@amazon.com, lagarcia@br.ibm.com, pbonzini@redhat.com, rcj@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH 12/17] migration-local: override hook_ram_load X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Override hook_ram_load to receive the pipe file descriptor passed by source process and page address which will be extracted to vmsplice the page data from pipe. Signed-off-by: Lei Li --- migration-local.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 59 insertions(+), 0 deletions(-) diff --git a/migration-local.c b/migration-local.c index 5f98a01..ce4c070 100644 --- a/migration-local.c +++ b/migration-local.c @@ -231,10 +231,69 @@ static size_t qemu_local_save_ram(QEMUFile *f, void *opaque, return RAM_SAVE_CONTROL_NOT_SUPP; } +static int qemu_local_ram_load(QEMUFile *f, void *opaque, + ram_addr_t addr, uint64_t flags) +{ + QEMUFileLocal *s = opaque; + struct iovec iov; + ssize_t ret = -EINVAL; + + if (!s->pipefd_received) { + /* + * send_pipefd was called at this point, and it wrote one + * byte to the stream. + */ + qemu_get_byte(s->file); + s->pipefd_received = true; + } + + if (s->pipefd_passed) { + void *host; + /* + * Extract the page address from the 8-byte record and + * read the page data from the pipe. + */ + host = qemu_get_ram_ptr(addr); + + iov.iov_base = host; + iov.iov_len = TARGET_PAGE_SIZE; + + /* + * The flag SPLICE_F_MOVE is introduced in kernel for the page + * flipping feature in QEMU, which will move pages rather than + * copying, previously unused. + * + * If a move is not possible the kernel will transparently fall + * back to copying data. + * + * For older kernels the SPLICE_F_MOVE would be ignored and a copy + * would occur. + */ + + ret = vmsplice(s->pipefd[0], &iov, 1, SPLICE_F_MOVE); + if (ret == -1) { + if (errno != EAGAIN && errno != EINTR) { + fprintf(stderr, "vmsplice() load error: %s", strerror(errno)); + return ret; + } + DPRINTF("vmsplice load error\n"); + } else if (ret == 0) { + DPRINTF(stderr, "load_page: zero read\n"); + } + + DPRINTF("vmsplice (read): %zu\n", ret); + return ret; + } + + return -EINVAL; +} + + static const QEMUFileOps pipe_read_ops = { .get_fd = qemu_local_get_sockfd, .get_buffer = qemu_local_get_buffer, .close = qemu_local_close, + .hook_ram_load = qemu_local_ram_load }; static const QEMUFileOps pipe_write_ops = {