From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Hansen <dave.hansen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH v5 09/32] x86/mm: Provide general kernel support for
	memory encryption
Date: Mon, 24 Apr 2017 08:57:17 -0700
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To: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>, linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Cc: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Rik van Riel <riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Brijesh Singh <brijesh.singh-5C7GfCeVMHo@public.gmane.org>, Toshimitsu Kani <toshi.kani-ZPxbGqLxI0U@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>, Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Andrey Ryabinin <aryabinin-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>, Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, "Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>, Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>, Paolo Bonzini <pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Alexander Potapenko <glider-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Larry Woodman <lwoodman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
List-Id: linux-efi@vger.kernel.org

On 04/24/2017 08:53 AM, Tom Lendacky wrote:
> On 4/21/2017 4:52 PM, Dave Hansen wrote:
>> On 04/18/2017 02:17 PM, Tom Lendacky wrote:
>>> @@ -55,7 +57,7 @@ static inline void copy_user_page(void *to, void
>>> *from, unsigned long vaddr,
>>>      __phys_addr_symbol(__phys_reloc_hide((unsigned long)(x)))
>>>
>>>  #ifndef __va
>>> -#define __va(x)            ((void *)((unsigned long)(x)+PAGE_OFFSET))
>>> +#define __va(x)            ((void *)(__sme_clr(x) + PAGE_OFFSET))
>>>  #endif
>>
>> It seems wrong to be modifying __va().  It currently takes a physical
>> address, and this modifies it to take a physical address plus the SME
>> bits.
> 
> This actually modifies it to be sure the encryption bit is not part of
> the physical address.

If SME bits make it this far, we have a bug elsewhere.  Right?  Probably
best not to paper over it.