From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34602) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8ha2-0003Sl-IM for qemu-devel@nongnu.org; Fri, 03 Jun 2016 01:23:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8ha0-0001PZ-IN for qemu-devel@nongnu.org; Fri, 03 Jun 2016 01:23:33 -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> <5750F1C5.4060000@163.com> From: Mark Cave-Ayland Message-ID: <57511422.6020901@ilande.co.uk> Date: Fri, 3 Jun 2016 06:22:42 +0100 MIME-Version: 1.0 In-Reply-To: <5750F1C5.4060000@163.com> Content-Type: text/plain; charset=utf-8 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: xiaoqiang zhao , Paolo Bonzini , qemu-devel@nongnu.org Cc: qemu-block@nongnu.org On 03/06/16 03:56, xiaoqiang zhao wrote: > 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. I've just sent through a patch which fixes the issue for me - please test and report back! Paolo - not sure if it's worth a follow-up patch that renames the relevant _readv/_writev functions in scsi-disk.c to _preadv/_pwritev to try and help avoid such confusion in future? ATB, Mark.