From: Dave Hansen <dave.hansen@intel.com>
To: "Thomas Hellström (VMware)" <thomas_os@shipmail.org>,
"Daniel Vetter" <daniel@ffwll.ch>
Cc: dri-devel <dri-devel@lists.freedesktop.org>,
pv-drivers@vmware.com,
"VMware Graphics" <linux-graphics-maintainer@vmware.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Tom Lendacky" <thomas.lendacky@amd.com>,
"Thomas Hellstrom" <thellstrom@vmware.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Heiko Carstens" <heiko.carstens@de.ibm.com>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Andy Lutomirski" <luto@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Christian König" <christian.koenig@amd.com>
Subject: Re: [PATCH v2 3/4] drm/ttm, drm/vmwgfx: Correctly support support AMD memory encryption
Date: Tue, 3 Sep 2019 13:51:28 -0700 [thread overview]
Message-ID: <7fa3b178-b9b4-2df9-1eee-54e24d48342e@intel.com> (raw)
In-Reply-To: <bed2a2d9-17f0-24bd-9f4a-c7ee27f6106e@shipmail.org>
On 9/3/19 1:36 PM, Thomas Hellström (VMware) wrote:
> So the question here should really be, can we determine already at mmap
> time whether backing memory will be unencrypted and adjust the *real*
> vma->vm_page_prot under the mmap_sem?
>
> Possibly, but that requires populating the buffer with memory at mmap
> time rather than at first fault time.
I'm not connecting the dots.
vma->vm_page_prot is used to create a VMA's PTEs regardless of if they
are created at mmap() or fault time. If we establish a good
vma->vm_page_prot, can't we just use it forever for demand faults?
Or, are you concerned that if an attempt is made to demand-fault page
that's incompatible with vma->vm_page_prot that we have to SEGV?
> And it still requires knowledge whether the device DMA is always
> unencrypted (or if SEV is active).
I may be getting mixed up on MKTME (the Intel memory encryption) and
SEV. Is SEV supported on all memory types? Page cache, hugetlbfs,
anonymous? Or just anonymous?
next prev parent reply other threads:[~2019-09-03 20:51 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 13:15 [PATCH v2 0/4] Have TTM support SEV encryption with coherent memory Thomas Hellström (VMware)
2019-09-03 13:15 ` [PATCH v2 1/4] x86/mm: Export force_dma_unencrypted Thomas Hellström (VMware)
2019-09-03 13:46 ` Christoph Hellwig
2019-09-03 14:32 ` Thomas Hellström (VMware)
2019-09-03 16:22 ` Christoph Hellwig
2019-09-03 20:46 ` Thomas Hellström (VMware)
2019-09-03 21:41 ` Andy Lutomirski
2019-09-04 6:58 ` Christoph Hellwig
2019-09-04 7:32 ` Thomas Hellström (VMware)
2019-09-04 12:22 ` Christoph Hellwig
2019-09-04 17:28 ` Thomas Hellström (VMware)
2019-09-03 15:14 ` Dave Hansen
2019-09-03 18:50 ` Thomas Hellström (VMware)
2019-09-03 13:15 ` [PATCH v2 2/4] s390/mm: " Thomas Hellström (VMware)
2019-09-03 13:46 ` Christoph Hellwig
2019-09-03 13:15 ` [PATCH v2 3/4] drm/ttm, drm/vmwgfx: Correctly support support AMD memory encryption Thomas Hellström (VMware)
2019-09-03 19:38 ` Dave Hansen
2019-09-03 19:51 ` Daniel Vetter
2019-09-03 19:55 ` Dave Hansen
2019-09-03 20:36 ` Thomas Hellström (VMware)
2019-09-03 20:51 ` Dave Hansen [this message]
2019-09-03 21:05 ` Thomas Hellström (VMware)
2019-09-03 21:46 ` Andy Lutomirski
2019-09-03 22:08 ` Thomas Hellström (VMware)
2019-09-03 22:15 ` Thomas Hellström (VMware)
2019-09-03 23:10 ` Dave Hansen
2019-09-04 8:34 ` Thomas Hellström (VMware)
2019-09-03 23:15 ` Andy Lutomirski
2019-09-04 6:49 ` Thomas Hellström (VMware)
2019-09-04 7:53 ` Daniel Vetter
2019-09-04 10:37 ` Thomas Hellström (VMware)
2019-09-04 11:43 ` Daniel Vetter
2019-09-04 18:16 ` Christoph Hellwig
2019-09-04 7:33 ` Koenig, Christian
2019-09-04 8:19 ` Thomas Hellström (VMware)
2019-09-04 8:42 ` Thomas Hellström (VMware)
2019-09-04 11:10 ` Koenig, Christian
2019-09-04 12:35 ` Thomas Hellström (VMware)
2019-09-04 13:05 ` Thomas Hellström (VMware)
2019-09-03 13:15 ` [PATCH v2 4/4] drm/ttm: Cache dma pool decrypted pages when AMD SEV is active Thomas Hellström (VMware)
2019-09-03 15:18 ` [PATCH v2 0/4] Have TTM support SEV encryption with coherent memory Daniel Vetter
2019-09-05 10:43 ` Thomas Hellström (VMware)
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