[Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

Jan Beulich JBeulich at suse.com
Fri Jul 27 03:04:12 EDT 2012


>>> On 26.07.12 at 17:33, Stefano Stabellini <stefano.stabellini at eu.citrix.com> wrote:
> In order for privcmd mmap to work correctly, xen_remap_domain_mfn_range
> needs to be implemented for HVM guests.
> If it is not, mmap is going to fail later on.

Somehow, for me at least, this description doesn't connect to the
actual change.

> Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> ---
>  drivers/xen/privcmd.c |    4 ----
>  1 files changed, 0 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index ccee0f1..85226cb 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -380,10 +380,6 @@ static struct vm_operations_struct privcmd_vm_ops = {
>  
>  static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	/* Unsupported for auto-translate guests. */
> -	if (xen_feature(XENFEAT_auto_translated_physmap))
> -		return -ENOSYS;
> -

Is this safe on x86?

Jan

>  	/* DONTCOPY is essential for Xen because copy_page_range doesn't know
>  	 * how to recreate these mappings */
>  	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;





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