Hi Julien,
> -----Original Message-----
> From: Xen-devel <xen-devel-boun...@lists.xenproject.org> On Behalf Of
> Julien Grall
> Sent: 2022年11月7日 2:55
> To: Wei Chen <wei.c...@arm.com>; xen-devel@lists.xenproject.org
> Cc: nd <n...@arm.com>; Stefano Stabellini <sstabell...@kernel.org>; Bertrand
> Marquis <bertrand.marq...@arm.com>; Volodymyr Babchuk
> <volodymyr_babc...@epam.com>; Henry Wang <henry.w...@arm.com>
> Subject: Re: [PATCH v6 02/11] xen/arm: add iounmap after initrd has been
> loaded in domain_build
>
> (+ Henry)
>
> Hi,
>
> On 04/11/2022 10:07, Wei Chen wrote:
> > domain_build use ioremap_wc to map a new non-cacheable virtual
>
> s/use/uses/
>
> > address for initrd. After Xen copy initrd from this address to
> > guest, this new allocated virtual address has not been unmapped.
> >
> > So in this patch, we add an iounmap to the end of domain_build,
> > after Xen loaded initrd to guest memory.
> >
>
> Please a fixes tag. The issue was introduced by commit bb7e6d565d92.
>
> > Signed-off-by: Wei Chen <wei.c...@arm.com>
> > ---
> > xen/arch/arm/domain_build.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > index 4fb5c20b13..bd30d3798c 100644
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -3418,6 +3418,8 @@ static void __init initrd_load(struct kernel_info
> *kinfo)
> > initrd, len);
> > if ( res != 0 )
> > panic("Unable to copy the initrd in the hwdom memory\n");
> > +
> > + iounmap(initrd);
>
> This looks good to me. But I am wondering whether using ioremap_wc() is
> actually correct because we are reading the region. So it seems strang
> to map it with write-combine.
>
> So I would consider to use ioremap_cache(). That said, this would be a
> separate patch.
>
Ok, we will try to use ioremap_cache and test it. If everything works
well we will introduce a separate patch in next version.
Cheers,
Wei Chen
> I think this wants to be in 4.17. This will avoid Xen to have two
> mappings with different caching attribute (initrd is part of the RAM and
> therefore directmap).
>
> Cheers,
>
> --
> Julien Grall
