From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41739) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8fHl-0008AR-1n for qemu-devel@nongnu.org; Thu, 02 Jun 2016 22:56:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8fHk-0003PT-78 for qemu-devel@nongnu.org; Thu, 02 Jun 2016 22:56:33 -0400 References: <1464008051-6429-1-git-send-email-pbonzini@redhat.com> <1464008051-6429-5-git-send-email-pbonzini@redhat.com> <574F326B.901@ilande.co.uk> From: xiaoqiang zhao Message-ID: <5750F1C5.4060000@163.com> Date: Fri, 3 Jun 2016 10:56:05 +0800 MIME-Version: 1.0 In-Reply-To: <574F326B.901@ilande.co.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 4/7] scsi-disk: introduce dma_readv and dma_writev List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org Cc: Mark Cave-Ayland , qemu-block@nongnu.org 在 2016年06月02日 03:07, Mark Cave-Ayland 写道: > On 23/05/16 13:54, Paolo Bonzini wrote: > >> >These are replacements for blk_aio_preadv and blk_aio_pwritev that allow >> >customization of the data path. They reuse the DMA helpers' DMAIOFunc >> >callback type, so that the same function can be used in either the >> >QEMUSGList or the bounce-buffered case. >> > >> >This customization will be needed in the next patch to do zero-copy >> >SG_IO on scsi-block. >> > >> >Signed-off-by: Paolo Bonzini >> >--- >> > hw/scsi/scsi-disk.c | 63 +++++++++++++++++++++++++++++++++++++++++++---------- >> > 1 file changed, 52 insertions(+), 11 deletions(-) >> > > Hi Paolo, > > This patch appears to break qemu-system-sparc booting from CDROM with > the following command line: > > ./qemu-system-sparc -cdrom debian-40r4a-sparc-netinst.iso -boot d > > Instead of booting straight into SILO, OpenBIOS hangs when trying to > read from the CDROM device. Paolo: By using git bisect on master branch , I found this patch also break qemu-system-arm from booting. command line: qemu-system-arm -M versatilepb -kernel vmlinuz-3.2.0-4-versatile -initrd initrd.img-3.2.0-4-versatile -hda /home/hitmoon/debian_wheezy_armel_standard.qcow2 -append 'root=/dev/sda1' The booting process stops at mounting the root partition and after timeout droped into a initramfs shell. The device '/dev/sda1' is presented . I guess it can not read properly from sda1.