Re: [Xen-devel] [PATCH 2/2] swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single

[Luis Henriques <luis.henriques@canonical.com>]

On Mon, Jan 26, 2015 at 10:53:27AM +0000, Ian Campbell wrote:
> On Fri, 2014-11-21 at 17:00 +0000, Stefano Stabellini wrote:
> > Need to pass the pointer within the swiotlb internal buffer to the
> > swiotlb library, that in the case of xen_unmap_single is dev_addr, not
> > paddr.
> > 
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > CC: konrad.wilk@oracle.com
> > CC: stable@vger.kernel.org
> 
> This went into mainline as 2c3fc8d26dd0 "swiotlb-xen: pass dev_addr to
> swiotlb_tbl_unmap_single" but was reverted in dbdd74763f1f.
> 
> However it seems that 2c3fc8d26dd0 has made it into at least some stable
> kernel trees:
>         v3.18.3 as 2129c43d41e9
>         v3.16.7-ckt4 as 94ab279b0c9a
>         v3.14.29 as 3394691d34fc
>         v3.10.65 as 81cb80b578c5
> so it should be reverted there too. This is causing issues in the field
> such as https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=776237.
> 
> v3.17, v3.15, v3.13.11-ckt14, v3.12.x, v3.11.x appear clean, I stopped
> going backwards at v3.10.
> 

Thanks a lot, Ian.  I'll queue commit dbdd74763f1f for the next 3.16
kernel release.

Cheers,
--
Lu�s

> Cheers,
> Ian.
> 
> > ---
> >  drivers/xen/swiotlb-xen.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> > index 810ad41..5ea1e3c 100644
> > --- a/drivers/xen/swiotlb-xen.c
> > +++ b/drivers/xen/swiotlb-xen.c
> > @@ -451,7 +451,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
> >  
> >  	/* NOTE: We use dev_addr here, not paddr! */
> >  	if (is_xen_swiotlb_buffer(dev_addr)) {
> > -		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
> > +		swiotlb_tbl_unmap_single(hwdev, dev_addr, size, dir);
> >  		return;
> >  	}
> >  
> 
>