Re: [PATCH] xen: don't use privcmd_call() from xen_mc_flush()

From: Juergen Gross
Date: Tue Aug 07 2018 - 11:17:07 EST


On 07/08/18 16:02, Boris Ostrovsky wrote:
> On 08/07/2018 09:11 AM, Juergen Gross wrote:
>> On 13/06/18 11:58, Juergen Gross wrote:
>>> Using privcmd_call() for a singleton multicall seems to be wrong, as
>>> privcmd_call() is using stac()/clac() to enable hypervisor access to
>>> Linux user space.
>>>
>>> Add a new xen_single_call() function to be use for that purpose.
>>>
>>> Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
>>> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
>> Boris, any objections?
>
>
> I think Jan wanted a change in commit message. I can commit with this:
>
> "Using privcmd_call() for a singleton multicall seems to be wrong, as
> privcmd_call() is using stac()/clac() to enable hypervisor access to
> Linux user space.
>
> Even if currently not a problem (pv domains can't use SMAP while HVM
> and PVH domains can't use multicalls) things might change when
> PVH dom0 support is added to the kernel."

This would be fine, thanks.


Juergen