Re: [PATCH] virtio-gpu: fix unmap the already mapped items

[Li Zhijian]

On 8/21/20 6:07 PM, Gerd Hoffmann wrote:
> On Fri, Aug 21, 2020 at 04:49:45PM +0800, Li Zhijian wrote:
> > we go here either (!(*iov)[i].iov_base) or (len != l), so we need to consider
> > to unmap the 'i'th item as well when the 'i'th item is not nil
> >
> > Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> > ---
> >   hw/display/virtio-gpu.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
> > index 5f0dd7c150..1f777e43ff 100644
> > --- a/hw/display/virtio-gpu.c
> > +++ b/hw/display/virtio-gpu.c
> > @@ -656,7 +656,7 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
> >               qemu_log_mask(LOG_GUEST_ERROR, "%s: failed to map MMIO memory for"
> >                             " resource %d element %d\n",
> >                             __func__, ab->resource_id, i);
> > -            virtio_gpu_cleanup_mapping_iov(g, *iov, i);
> > +            virtio_gpu_cleanup_mapping_iov(g, *iov, i + !!(*iov)[i].iov_base);
> Cute trick, but the code should be readable without having to dig out
> the commit message which explains it.  Can we have something simpler
> along the lines of "if (iov_base) { i++; /* cleanup partial map */ }"
> please?
make sense !

Thanks
Zhijian

> thanks,
>    Gerd