From: Alex Williamson <alex.williamson@redhat.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: iommu@lists.linux-foundation.org, Ashok Raj <ashok.raj@intel.com>,
Mario.Limonciello@dell.com,
Michael Jamet <michael.jamet@intel.com>,
Christian Kellner <ckellner@redhat.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Yehezkel Bernat <YehezkelShB@gmail.com>,
Anthony Wong <anthony.wong@canonical.com>,
Andreas Noever <andreas.noever@gmail.com>,
Lukas Wunner <lukas@wunner.de>,
Jacob jun Pan <jacob.jun.pan@intel.com>,
linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
linux-acpi@vger.kernel.org, David Woodhouse <dwmw2@infradead.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] iommu/vt-d: Force IOMMU on for platform opt in hint
Date: Mon, 12 Nov 2018 11:09:00 -0700 [thread overview]
Message-ID: <20181112110900.16cfee48@t450s.home> (raw)
In-Reply-To: <20181112160628.86620-3-mika.westerberg@linux.intel.com>
On Mon, 12 Nov 2018 19:06:26 +0300
Mika Westerberg <mika.westerberg@linux.intel.com> wrote:
> From: Lu Baolu <baolu.lu@linux.intel.com>
>
> Intel VT-d spec added a new DMA_CTRL_PLATFORM_OPT_IN_FLAG flag
> in DMAR ACPI table for BIOS to report compliance about platform
> initiated DMA restricted to RMRR ranges when transferring control
> to the OS. The OS treats this as a hint that the IOMMU should be
> enabled to prevent DMA attacks from possible malicious devices.
Does this in any way suggest that there are additional recommended uses
cases from Intel for RMRRs? My concern here is the incompatibility we
have with RMRRs and device assignment as we currently cannot assign
devices where the IOVA address space is encumbered by RMRR
requirements. Unfortunately RMRRs do not indicate any sort or
lifespan, so firmware enabling an RMRR simply to support some boot-time
DMA encumbers the device with that RMRR for the life of that boot,
unless we have VT-d code that decides it knows better. Thanks,
Alex
next prev parent reply other threads:[~2018-11-12 18:09 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 [this message]
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
[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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