Re: [PATCH 3/6] x86/sev-es: Use __put_user()/__get_user

[Juergen Gross]

On 12.05.21 10:50, 'Joerg Roedel' wrote:
> On Wed, May 12, 2021 at 10:16:12AM +0200, Juergen Gross wrote:
> > You want something like xen_safe_[read|write]_ulong().
>
>  From a first glance I can't see it, what is the difference between the
> xen_safe_*_ulong() functions and __get_user()/__put_user()? The only
> difference I can see is that __get/__put_user() support different access
> sizes, but neither of those disables page-faults by itself, for example.
>
> Couldn't these xen-specific functions not also be replaces by
> __get_user()/__put_user()?

No, those were used before, but commit 9da3f2b7405440 broke Xen's use
case. That is why I did commit 1457d8cf7664f.


Juergen

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