Messages in this thread | | | Date | Wed, 25 Jul 2012 11:05:39 +0100 | From | Stefan Hajnoczi <> | Subject | Re: [PATCH] scsi: virtio-scsi: Fix address translation failure of HighMem pages used by sg list |
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On Wed, Jul 25, 2012 at 04:00:19PM +0800, Wang Sen wrote: > When using the commands below to write some data to a virtio-scsi LUN of the > QEMU guest(32-bit) with 1G physical memory(qemu -m 1024), the qemu will crash. > > # sudo mkfs.ext4 /dev/sdb (/dev/sdb is the virtio-scsi LUN.) > # sudo mount /dev/sdb /mnt > # dd if=/dev/zero of=/mnt/file bs=1M count=1024 > > In current implementation, sg_set_buf is called to add buffers to sg list which > is put into the virtqueue eventually. But there are some HighMem pages in > table->sgl can not get virtual address by sg_virt. So, sg_virt(sg_elem) may > return NULL value. This will cause QEMU exit when virtqueue_map_sg is called > in QEMU because an invalid GPA is passed by virtqueue. > > My solution is using sg_set_page instead of sg_set_buf. > > I have tested the patch on my workstation. QEMU would not crash any more. > > Signed-off-by: Wang Sen <senwang@linux.vnet.ibm.com> > --- > drivers/scsi/virtio_scsi.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-)
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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