On Wed, 15 Nov 2017, Julien Grall wrote:
> The function get_page_from_gva is used by copy_*_guest helpers to
> translate a guest virtual address to a machine physical address and take
> reference on the page.
>
> There are a couple of errors path that will return the same value making
^ paths
> difficult to know the exact error. Add more debug in each error patch
^ it difficult
> only for debug-build.
>
> This should help narrowing down the intermittent failure with the
> hypercall GNTTABOP_copy (see [1]).
>
> [1] https://lists.xen.org/archives/html/xen-devel/2017-11/msg00942.html
>
> Signed-off-by: Julien Grall <julien.gr...@linaro.org>
Acked-by: Stefano Stabellini <sstabell...@kernel.org>
fixed on commit
> ---
> xen/arch/arm/p2m.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index f6b3d8e421..417609ede2 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -1428,16 +1428,29 @@ struct page_info *get_page_from_gva(struct vcpu *v,
> vaddr_t va,
> par = gvirt_to_maddr(va, &maddr, flags);
>
> if ( par )
> + {
> + dprintk(XENLOG_G_DEBUG,
> + "%pv: gvirt_to_maddr failed va=%#"PRIvaddr" flags=0x%lx
> par=%#"PRIx64"\n",
> + v, va, flags, par);
> goto err;
> + }
>
> if ( !mfn_valid(maddr_to_mfn(maddr)) )
> + {
> + dprintk(XENLOG_G_DEBUG, "%pv: Invalid MFN %#"PRI_mfn"\n",
> + v, mfn_x(maddr_to_mfn(maddr)));
> goto err;
> + }
>
> page = mfn_to_page(maddr_to_mfn(maddr));
> ASSERT(page);
>
> if ( unlikely(!get_page(page, d)) )
> + {
> + dprintk(XENLOG_G_DEBUG, "%pv: Failing to acquire the MFN
> %#"PRI_mfn"\n",
> + v, mfn_x(maddr_to_mfn(maddr)));
> page = NULL;
> + }
>
> err:
> if ( !page && p2m->mem_access_enabled )
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
