Re: [Xen-devel] [PATCH v2] x86/xen: fix pv boot

[Andrew Cooper]

On 07/11/18 17:01, Juergen Gross wrote:
> Commit 9da3f2b7405440 ("x86/fault: BUG() when uaccess helpers fault on
> kernel addresses") introduced a regression for booting Xen PV guests.
>
> Xen PV guests are using __put_user() and __get_user() for accessing the
> p2m map (physical to machine frame number map) as accesses might fail
> in case of not populated areas of the map.
>
> With above commit using __put_user() and __get_user() for accessing
> kernel pages is no longer valid. So replace the Xen hack by adding
> appropriate p2m access functions using the default fixup handler.
>
> Fixes: 9da3f2b7405440 ("x86/fault: BUG() when uaccess helpers fault on kernel addresses")
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>