On the platforms which are x2apic and interrupt-remapping
capable, Linux kernel is enabling x2apic even if the BIOS
doesn't. This is to take advantage of the features that x2apic
brings in.
Some of the OEM platforms are running into issues because of
this, as their bios is not x2apic aware. For example, this was
resulting in interrupt migration issues on one of the platforms.
Also if the BIOS SMI handling uses APIC interface to send SMI's,
then the BIOS need to be aware of x2apic mode that OS has
enabled.
On some of these platforms, BIOS doesn't have a HW mechanism to
turnoff the x2apic feature to prevent OS from enabling it.
To resolve this mess, recent changes to the VT-d2 specification:
http://download.intel.com/technology/computing/vptech/Intel(r)_VT_for_Direct_IO.pdf
includes a mechanism that provides BIOS a way to request system
software to opt out of enabling x2apic mode.
Look at the x2apic optout flag in the DMAR tables before
enabling the x2apic mode in the platform. Also print a warning
that we have disabled x2apic based on the BIOS request.
Kernel boot parameter "intremap=no_x2apic_optout" can be used to
override the BIOS x2apic optout request.
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: joerg.roedel@amd.com
Cc: tony.luck@intel.com
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/20110824001456.171766616@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The stubs for CONFIG_INTR_REMAP disabled need to be functions
instead of values to eliminate build warnings.
arch/x86/kernel/apic/apic.c: In function 'lapic_suspend':
arch/x86/kernel/apic/apic.c:2060:3: warning: statement with no effect
arch/x86/kernel/apic/apic.c: In function 'lapic_resume':
arch/x86/kernel/apic/apic.c:2137:3: warning: statement with no effect
Reported-and-Tested-by: Fabio Comolli <fabio.comolli@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <20101122124834.74429004.randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
irq_2_iommu is in struct irq_cfg, so we can do the irq_remapped check
based on irq_cfg instead of going through a lookup function. That's
especially interesting in the eoi_ioapic_irq() hotpath.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
That interrupt remapping code is x86 specific and tied to the io_apic
code. No need for separate allocator functions in the interrupt
remapping code. This allows to simplify the code and irq_2_iommu is
small (13 bytes on 64bit) so it's not a real problem even if interrupt
remapping is runtime disabled. If it's compile time disabled the
impact is zero.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
We return 1 if the IOMMU has been detected. Zero or an error number
if we failed to find it. This is in preperation of using the IOMMU_INIT
so that we can detect whether an IOMMU is present. I have not
tested this for regression on Calgary, nor on AMD Vi chipsets as
I don't have that hardware.
CC: Muli Ben-Yehuda <muli@il.ibm.com>
CC: "Jon D. Mason" <jdmason@kudzu.us>
CC: "Darrick J. Wong" <djwong@us.ibm.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: David Woodhouse <David.Woodhouse@intel.com>
CC: Chris Wright <chrisw@sous-sol.org>
CC: Yinghai Lu <yinghai@kernel.org>
CC: Joerg Roedel <joerg.roedel@amd.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <1282845485-8991-3-git-send-email-konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'timers-for-linus-hpet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: hpet: Make WARN_ON understandable
x86: arch specific support for remapping HPET MSIs
intr-remap: generic support for remapping HPET MSIs
x86, hpet: Simplify the HPET code
x86, hpet: Disable per-cpu hpet timer if ARAT is supported
This changes detect_intel_iommu() to set intel_iommu_init() to
iommu_init hook if detect_intel_iommu() finds the IOMMU.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-6-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: build fix for the !CONFIG_DMAR case ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Generic support for remapping HPET MSI's by parsing the HPET timer block
device scope in the ACPI DRHD tables. This is needed for platforms
supporting interrupt-remapping and MSI capable HPET timer block.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Jay Fenlason <fenlason@redhat.com>
LKML-Reference: <20090804190729.477649000@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
To support domain-isolation usages, the platform hardware must be
capable of uniquely identifying the requestor (source-id) for each
interrupt message. Without source-id checking for interrupt remapping
, a rouge guest/VM with assigned devices can launch interrupt attacks
to bring down anothe guest/VM or the VMM itself.
This patch adds source-id checking for interrupt remapping, and then
really isolates interrupts for guests/VMs with assigned devices.
Because PCI subsystem is not initialized yet when set up IOAPIC
entries, use read_pci_config_byte to access PCI config space directly.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* git://git.infradead.org/~dwmw2/iommu-2.6.31:
intel-iommu: Fix one last ia64 build problem in Pass Through Support
VT-d: support the device IOTLB
VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
VT-d: add device IOTLB invalidation support
VT-d: parse ATSR in DMA Remapping Reporting Structure
PCI: handle Virtual Function ATS enabling
PCI: support the ATS capability
intel-iommu: dmar_set_interrupt return error value
intel-iommu: Tidy up iommu->gcmd handling
intel-iommu: Fix tiny theoretical race in write-buffer flush.
intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
intel-iommu: Clean up handling of "caching mode" vs. context flushing.
VT-d: fix invalid domain id for KVM context flush
Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
Intel IOMMU Pass Through Support
Fix up trivial conflicts in drivers/pci/{intel-iommu.c,intr_remapping.c}
Parse the Root Port ATS Capability Reporting Structure in the DMA
Remapping Reporting Structure ACPI table.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Currently, when x2apic is not enabled, interrupt remapping
will be enabled in init_dmars(), where it is too late to remap
ioapic interrupts, that is, ioapic interrupts are really in
compatibility mode, not remappable mode.
This patch always enables interrupt remapping before ioapic
setup, it guarantees all interrupts will be remapped when
interrupt remapping is enabled. Thus it doesn't need to set
the compatibility interrupt bit.
[ Impact: refactor intr-remap init sequence, enable fuller remap mode ]
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-4-git-send-email-weidong.han@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We were comparing {bus,devfn} and assuming that a match meant it was the
same device. It doesn't -- the same {bus,devfn} can exist in
multiple PCI domains. Include domain number in device identification
(and call it 'segment' in most places, because there's already a lot of
references to 'domain' which means something else, and this code is
infected with ACPI thinking already).
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch enables suspend/resume for interrupt remapping. During suspend,
interrupt remapping is disabled. When resume, interrupt remapping is enabled
again.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Impact: cleanup
Clean up #ifdefs and replace them with helper functions.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: cleanup/sanitization
Start from a sane state while enabling dma and interrupt-remapping, by
clearing the previous recorded faults and disabling previously
enabled queued invalidation and interrupt-remapping.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: interface augmentation (not yet used)
Enable fault handling flow for intr-remapping aswell. Fault handling
code now shared by both dma-remapping and intr-remapping.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This is only used in dmar.c and intel-iommu.h, so dma_remapping.h
seems like the appropriate place for it.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Very early detection of the DMAR tables will setup fixmap mapping. For
parsing these tables later (while enabling dma and/or interrupt remapping),
early fixmap mapping shouldn't be used. Fix it by calling table detection
routines again, which will call generic apci_get_table() for setting up
the correct mapping.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
MSI and MSI-X support for interrupt remapping infrastructure.
MSI address register will be programmed with interrupt-remapping table
entry(IRTE) index and the IRTE will contain information about the vector,
cpu destination, etc.
For MSI-X, all the IRTE's will be consecutively allocated in the table,
and the address registers will contain the starting index to the block
and the data register will contain the subindex with in that block.
This also introduces a new irq_chip for cleaner irq migration (in the process
context as opposed to the current irq migration in the context of an interrupt.
interrupt-remapping infrastructure will help us achieve this).
As MSI is edge triggered, irq migration is a simple atomic update(of vector
and cpu destination) of IRTE and flushing the hardware cache.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
IO-APIC support in the presence of interrupt-remapping infrastructure.
IO-APIC RTE will be programmed with interrupt-remapping table entry(IRTE)
index and the IRTE will contain information about the vector, cpu destination,
trigger mode etc, which traditionally was present in the IO-APIC RTE.
Introduce a new irq_chip for cleaner irq migration (in the process
context as opposed to the current irq migration in the context of an interrupt.
interrupt-remapping infrastructure will help us achieve this cleanly).
For edge triggered, irq migration is a simple atomic update(of vector
and cpu destination) of IRTE and flush the hardware cache.
For level triggered, we need to modify the io-apic RTE aswell with the update
vector information, along with modifying IRTE with vector and cpu destination.
So irq migration for level triggered is little bit more complex compared to
edge triggered migration. But the good news is, we use the same algorithm
for level triggered migration as we have today, only difference being,
we now initiate the irq migration from process context instead of the
interrupt context.
In future, when we do a directed EOI (combined with cpu EOI broadcast
suppression) to the IO-APIC, level triggered irq migration will also be
as simple as edge triggered migration and we can do the irq migration
with a simple atomic update to IO-APIC RTE.
TBD: some tests/changes needed in the presence of fixup_irqs() for
level triggered irq migration.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Allocate the iommu during the parse of DMA remapping hardware
definition structures. And also, introduce routines for device
scope initialization which will be explicitly called during
dma-remapping initialization.
These will be used for enabling interrupt remapping separately from the
existing DMA-remapping enabling sequence.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix an off by one bug in the fault reason string reporting function, and
clean up some of the code around this buglet.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MSI interrupt handler registrations and fault handling support for Intel-IOMMU
hadrware.
This patch enables the MSI interrupts for the DMA remapping units and in the
interrupt handler read the fault cause and outputs the same on to the console.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Actual intel IOMMU driver. Hardware spec can be found at:
http://www.intel.com/technology/virtualization
This driver sets X86_64 'dma_ops', so hook into standard DMA APIs. In this
way, PCI driver will get virtual DMA address. This change is transparent to
PCI drivers.
[akpm@linux-foundation.org: remove unneeded cast]
[akpm@linux-foundation.org: build fix]
[bunk@stusta.de: fix duplicate CONFIG_DMAR Makefile line]
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch supports the upcomming Intel IOMMU hardware a.k.a. Intel(R)
Virtualization Technology for Directed I/O Architecture and the hardware spec
for the same can be found here
http://www.intel.com/technology/virtualization/index.htm
FAQ! (questions from akpm, answers from ak)
> So... what's all this code for?
>
> I assume that the intent here is to speed things up under Xen, etc?
Yes in some cases, but not this code. That would be the Xen version of this
code that could potentially assign whole devices to guests. I expect this to
be only useful in some special cases though because most hardware is not
virtualizable and you typically want an own instance for each guest.
Ok at some point KVM might implement this too; i likely would use this code
for this.
> Do we
> have any benchmark results to help us to decide whether a merge would be
> justified?
The main advantage for doing it in the normal kernel is not performance, but
more safety. Broken devices won't be able to corrupt memory by doing random
DMA.
Unfortunately that doesn't work for graphics yet, for that need user space
interfaces for the X server are needed.
There are some potential performance benefits too:
- When you have a device that cannot address the complete address range an
IOMMU can remap its memory instead of bounce buffering. Remapping is likely
cheaper than copying.
- The IOMMU can merge sg lists into a single virtual block. This could
potentially speed up SG IO when the device is slow walking SG lists. [I
long ago benchmarked 5% on some block benchmark with an old MPT Fusion; but
it probably depends a lot on the HBA]
And you get better driver debugging because unexpected memory accesses from
the devices will cause a trappable event.
>
> Does it slow anything down?
It adds more overhead to each IO so yes.
This patch:
Add support for early detection and parsing of DMAR's (DMA Remapping) reported
to OS via ACPI tables.
DMA remapping(DMAR) devices support enables independent address translations
for Direct Memory Access(DMA) from Devices. These DMA remapping devices are
reported via ACPI tables and includes pci device scope covered by these DMA
remapping device.
For detailed info on the specification of "Intel(R) Virtualization Technology
for Directed I/O Architecture" please see
http://www.intel.com/technology/virtualization/index.htm
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
