From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmKyk-0008Be-3S for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VmKyb-00081E-5h for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:18 -0500 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:58918) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmKya-00080l-B6 for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:09 -0500 Received: from /spool/local by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 29 Nov 2013 20:07:06 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id F12743578052 for ; Fri, 29 Nov 2013 21:07:03 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rATA6poC4653420 for ; Fri, 29 Nov 2013 21:06:51 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rATA7397012685 for ; Fri, 29 Nov 2013 21:07:03 +1100 From: Lei Li Date: Fri, 29 Nov 2013 18:06:19 +0800 Message-Id: <1385719584-21114-13-git-send-email-lilei@linux.vnet.ibm.com> In-Reply-To: <1385719584-21114-1-git-send-email-lilei@linux.vnet.ibm.com> References: <1385719584-21114-1-git-send-email-lilei@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 12/17] migration-local: override hook_ram_load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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 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 76ec306..b086f38 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 movie pages rather than + * copying, previously unused. + * + * If a move is not possible the kernel will transparently falls + * 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 = { -- 1.7.7.6