From: Yehezkel Bernat <yehezkelshb@gmail.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: iommu@lists.linux-foundation.org, joro@8bytes.org,
David Woodhouse <dwmw2@infradead.org>,
baolu.lu@linux.intel.com, ashok.raj@intel.com,
Bjorn Helgaas <bhelgaas@google.com>,
rjw@rjwysocki.net, jacob.jun.pan@intel.com,
Andreas Noever <andreas.noever@gmail.com>,
michael.jamet@intel.com, lukas@wunner.de,
Christian Kellner <ckellner@redhat.com>,
Mario Limonciello <Mario.Limonciello@dell.com>,
Anthony Wong <anthony.wong@canonical.com>,
linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/4] thunderbolt: Export IOMMU based DMA protection support to userspace
Date: Tue, 13 Nov 2018 16:42:58 +0200 [thread overview]
Message-ID: <CA+CmpXt1cfqjz94=WsggKpNCUw3761-cewa_HTa0ETcYK7o+Hw@mail.gmail.com> (raw)
In-Reply-To: <20181113114020.GV2500@lahna.fi.intel.com>
On Tue, Nov 13, 2018 at 1:40 PM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> On Tue, Nov 13, 2018 at 01:13:31PM +0200, Yehezkel Bernat wrote:
> > On Tue, Nov 13, 2018 at 12:56 PM Mika Westerberg
> > <mika.westerberg@linux.intel.com> wrote:
> > >
> > > > Just one point:
> > > > Have you considered the option to add this property per (TBT?) device?
> > >
> > > No. ;-)
> > >
> > > You mean that one device uses security levels and another IOMMU? I don't
> > > think it is possible without having some sort of table in the IOMMU
> > > driver telling which devices it needs identity map and which not. Also
> > > not sure what would be the benefit?
> >
> > For performance, of course. If some devices are considered safe (maybe a list
> > communicated by platform firmware), the kernel may decide to configure them to
> > passthrough the IOMMU (I think I remember there is such an option, but maybe I'm
> > wrong.)
>
> At least I'm not aware of such an option. Windows for example enables
> IOMMU for everything and I think macOS does the same. In Linux (with
> these patches) we put all internal devices already passthrough mode so
> things like internal graphics should not be affected. eGPUs are
> different thing, though.
So your point here is "currently we do the IOMMU decisions system-wide; we can
always add a per-device attribute if needed"?
Fair enough.
So for this patch,
Reviewed-by: Yehezkel Bernat <YehezkelShB@gmail.com>
next prev parent reply other threads:[~2018-11-13 14:43 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 16:06 [PATCH 0/4] PCI / iommu / thunderbolt: IOMMU based DMA protection Mika Westerberg
2018-11-12 16:06 ` [PATCH 1/4] PCI / ACPI: Identify external PCI devices Mika Westerberg
2018-11-12 18:02 ` Lukas Wunner
2018-11-13 10:56 ` Lorenzo Pieralisi
2018-11-13 11:27 ` Mika Westerberg
2018-11-13 11:45 ` Lorenzo Pieralisi
2018-11-15 10:22 ` Mika Westerberg
2018-11-15 11:13 ` Lorenzo Pieralisi
2018-11-15 11:37 ` Mika Westerberg
2018-11-15 12:07 ` Lukas Wunner
2018-11-15 12:16 ` Mika Westerberg
2018-11-15 17:46 ` Lorenzo Pieralisi
2018-11-15 17:58 ` Yehezkel Bernat
2018-11-15 19:10 ` Mika Westerberg
2018-11-15 19:27 ` Lukas Wunner
2018-11-15 19:32 ` Mika Westerberg
2018-11-16 9:18 ` Christoph Hellwig
2018-11-16 9:32 ` Mika Westerberg
2018-11-22 10:48 ` Mika Westerberg
2018-11-22 10:59 ` Christoph Hellwig
2018-11-15 19:00 ` Mika Westerberg
2018-11-15 19:33 ` Mario.Limonciello
2018-11-16 10:57 ` Lorenzo Pieralisi
2018-11-20 21:43 ` Rafael J. Wysocki
2018-11-21 12:40 ` Lorenzo Pieralisi
2018-11-16 7:01 ` Mika Westerberg
2018-11-12 16:06 ` [PATCH 2/4] iommu/vt-d: Force IOMMU on for platform opt in hint Mika Westerberg
2018-11-12 17:49 ` Raj, Ashok
2018-11-12 18:09 ` Alex Williamson
2018-11-12 19:51 ` Raj, Ashok
2018-11-12 16:06 ` [PATCH 3/4] iommu/vt-d: Do not enable ATS for external devices Mika Westerberg
2018-11-12 17:53 ` Raj, Ashok
2018-11-12 16:06 ` [PATCH 4/4] thunderbolt: Export IOMMU based DMA protection support to userspace Mika Westerberg
2018-11-12 16:22 ` Mario.Limonciello
2018-11-13 10:36 ` Mika Westerberg
2018-11-12 16:59 ` Yehezkel Bernat
2018-11-13 10:55 ` Mika Westerberg
2018-11-13 11:13 ` Yehezkel Bernat
2018-11-13 11:40 ` Mika Westerberg
2018-11-13 14:42 ` Yehezkel Bernat [this message]
[not found] ` <20181113152038.GD2500@lahna.fi.intel.com>
2018-11-13 15:38 ` Yehezkel Bernat
2018-11-13 16:12 ` Mika Westerberg
2018-11-12 18:12 ` [PATCH 0/4] PCI / iommu / thunderbolt: IOMMU based DMA protection Lukas Wunner
2018-11-12 19:04 ` Yehezkel Bernat
2018-11-13 11:13 ` Mika Westerberg
2018-11-13 8:54 ` Joerg Roedel
2018-11-13 11:32 ` Mika Westerberg
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