According to the VT-d specification we need to clear the PPR bit in
the Page Request Status register when handling page requests, or the
hardware won't generate any more interrupts.
This wasn't actually necessary on SKL/KBL (which may well be the
subject of a hardware erratum, although it's harmless enough). But
other implementations do appear to get it right, and we only ever get
one interrupt unless we clear the PPR bit.
Reported-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@vger.kernel.org
This provides basic PASID support for endpoint devices, tested with a
version of the i915 driver.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As long as we use an identity mapping to work around the worst of the
hardware bugs which caused us to defeature it and change the definition
of the capability bit, we *can* use PASID support on the devices which
advertised it in bit 28 of the Extended Capability Register.
Allow people to do so with 'intel_iommu=pasid28' on the command line.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This array is indexed by the domain-id and contains the
pointers to the domains attached to this iommu. Modern
systems support 65536 domain ids, so that this array has a
size of 512kb, per iommu.
This is a huge waste of space, as the array is usually
sparsely populated. This patch makes the array
two-dimensional and allocates the memory for the domain
pointers on-demand.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull IOMMU updates from Joerg Roedel:
"This time with bigger changes than usual:
- A new IOMMU driver for the ARM SMMUv3.
This IOMMU is pretty different from SMMUv1 and v2 in that it is
configured through in-memory structures and not through the MMIO
register region. The ARM SMMUv3 also supports IO demand paging for
PCI devices with PRI/PASID capabilities, but this is not
implemented in the driver yet.
- Lots of cleanups and device-tree support for the Exynos IOMMU
driver. This is part of the effort to bring Exynos DRM support
upstream.
- Introduction of default domains into the IOMMU core code.
The rationale behind this is to move functionalily out of the IOMMU
drivers to common code to get to a unified behavior between
different drivers. The patches here introduce a default domain for
iommu-groups (isolation groups).
A device will now always be attached to a domain, either the
default domain or another domain handled by the device driver. The
IOMMU drivers have to be modified to make use of that feature. So
long the AMD IOMMU driver is converted, with others to follow.
- Patches for the Intel VT-d drvier to fix DMAR faults that happen
when a kdump kernel boots.
When the kdump kernel boots it re-initializes the IOMMU hardware,
which destroys all mappings from the crashed kernel. As this
happens before the endpoint devices are re-initialized, any
in-flight DMA causes a DMAR fault. These faults cause PCI master
aborts, which some devices can't handle properly and go into an
undefined state, so that the device driver in the kdump kernel
fails to initialize them and the dump fails.
This is now fixed by copying over the mapping structures (only
context tables and interrupt remapping tables) from the old kernel
and keep the old mappings in place until the device driver of the
new kernel takes over. This emulates the the behavior without an
IOMMU to the best degree possible.
- A couple of other small fixes and cleanups"
* tag 'iommu-updates-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (69 commits)
iommu/amd: Handle large pages correctly in free_pagetable
iommu/vt-d: Don't disable IR when it was previously enabled
iommu/vt-d: Make sure copied over IR entries are not reused
iommu/vt-d: Copy IR table from old kernel when in kdump mode
iommu/vt-d: Set IRTA in intel_setup_irq_remapping
iommu/vt-d: Disable IRQ remapping in intel_prepare_irq_remapping
iommu/vt-d: Move QI initializationt to intel_setup_irq_remapping
iommu/vt-d: Move EIM detection to intel_prepare_irq_remapping
iommu/vt-d: Enable Translation only if it was previously disabled
iommu/vt-d: Don't disable translation prior to OS handover
iommu/vt-d: Don't copy translation tables if RTT bit needs to be changed
iommu/vt-d: Don't do early domain assignment if kdump kernel
iommu/vt-d: Allocate si_domain in init_dmars()
iommu/vt-d: Mark copied context entries
iommu/vt-d: Do not re-use domain-ids from the old kernel
iommu/vt-d: Copy translation tables from old kernel
iommu/vt-d: Detect pre enabled translation
iommu/vt-d: Make root entry visible for hardware right after allocation
iommu/vt-d: Init QI before root entry is allocated
iommu/vt-d: Cleanup log messages
...
Pull x86 core updates from Ingo Molnar:
"There were so many changes in the x86/asm, x86/apic and x86/mm topics
in this cycle that the topical separation of -tip broke down somewhat -
so the result is a more traditional architecture pull request,
collected into the 'x86/core' topic.
The topics were still maintained separately as far as possible, so
bisectability and conceptual separation should still be pretty good -
but there were a handful of merge points to avoid excessive
dependencies (and conflicts) that would have been poorly tested in the
end.
The next cycle will hopefully be much more quiet (or at least will
have fewer dependencies).
The main changes in this cycle were:
* x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
Gleixner)
- This is the second and most intrusive part of changes to the x86
interrupt handling - full conversion to hierarchical interrupt
domains:
[IOAPIC domain] -----
|
[MSI domain] --------[Remapping domain] ----- [ Vector domain ]
| (optional) |
[HPET MSI domain] ----- |
|
[DMAR domain] -----------------------------
|
[Legacy domain] -----------------------------
This now reflects the actual hardware and allowed us to distangle
the domain specific code from the underlying parent domain, which
can be optional in the case of interrupt remapping. It's a clear
separation of functionality and removes quite some duct tape
constructs which plugged the remap code between ioapic/msi/hpet
and the vector management.
- Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
injection into guests (Feng Wu)
* x86/asm changes:
- Tons of cleanups and small speedups, micro-optimizations. This
is in preparation to move a good chunk of the low level entry
code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
Brian Gerst)
- Moved all system entry related code to a new home under
arch/x86/entry/ (Ingo Molnar)
- Removal of the fragile and ugly CFI dwarf debuginfo annotations.
Conversion to C will reintroduce many of them - but meanwhile
they are only getting in the way, and the upstream kernel does
not rely on them (Ingo Molnar)
- NOP handling refinements. (Borislav Petkov)
* x86/mm changes:
- Big PAT and MTRR rework: making the code more robust and
preparing to phase out exposing direct MTRR interfaces to drivers -
in favor of using PAT driven interfaces (Toshi Kani, Luis R
Rodriguez, Borislav Petkov)
- New ioremap_wt()/set_memory_wt() interfaces to support
Write-Through cached memory mappings. This is especially
important for good performance on NVDIMM hardware (Toshi Kani)
* x86/ras changes:
- Add support for deferred errors on AMD (Aravind Gopalakrishnan)
This is an important RAS feature which adds hardware support for
poisoned data. That means roughly that the hardware marks data
which it has detected as corrupted but wasn't able to correct, as
poisoned data and raises an APIC interrupt to signal that in the
form of a deferred error. It is the OS's responsibility then to
take proper recovery action and thus prolonge system lifetime as
far as possible.
- Add support for Intel "Local MCE"s: upcoming CPUs will support
CPU-local MCE interrupts, as opposed to the traditional system-
wide broadcasted MCE interrupts (Ashok Raj)
- Misc cleanups (Borislav Petkov)
* x86/platform changes:
- Intel Atom SoC updates
... and lots of other cleanups, fixlets and other changes - see the
shortlog and the Git log for details"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
x86/hpet: Use proper hpet device number for MSI allocation
x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
genirq: Prevent crash in irq_move_irq()
genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
iommu, x86: Properly handle posted interrupts for IOMMU hotplug
iommu, x86: Provide irq_remapping_cap() interface
iommu, x86: Setup Posted-Interrupts capability for Intel iommu
iommu, x86: Add cap_pi_support() to detect VT-d PI capability
iommu, x86: Avoid migrating VT-d posted interrupts
iommu, x86: Save the mode (posted or remapped) of an IRTE
iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
iommu: dmar: Provide helper to copy shared irte fields
iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
iommu: Add new member capability to struct irq_remap_ops
x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
...
When we are booting into a kdump kernel and find IR enabled,
copy over the contents of the previous IR table so that
spurious interrupts will not be target aborted.
Tested-by: ZhenHua Li <zhen-hual@hp.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Add code to detect whether translation is already enabled in
the IOMMU. Save this state in a flags field added to
struct intel_iommu.
Tested-by: ZhenHua Li <zhen-hual@hp.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The existing hardware implementations with PASID support advertised in
bit 28? Forget them. They do not exist. Bit 28 means nothing. When we
have something that works, it'll use bit 40. Do not attempt to infer
anything meaningful from bit 28.
This will be reflected in an updated VT-d spec in the extremely near
future.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As far back as I can see (which right now is a draft of the v1.2 spec
dating from September 2008), bits 24-31 of the Extended Capability Register
have already been reserved. I have no idea why anyone ever thought there
would be multiple sets of IOTLB registers, but we've never supported them
and all we do is make sure we map enough MMIO space for them.
Kill it dead. Those bits do actually have a different meaning now.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Register our DRHD IOMMUs, cross link devices, and provide a base set
of attributes for the IOMMU. Note that IRQ remapping support parses
the DMAR table very early in boot, well before the iommu_class can
reasonably be setup, so our registration is split between
intel_iommu_init(), which occurs later, and alloc_iommu(), which
typically occurs much earlier, but may happen at any time later
with IOMMU hot-add support.
On a typical desktop system, this provides the following (pruned):
$ find /sys | grep dmar
/sys/devices/virtual/iommu/dmar0
/sys/devices/virtual/iommu/dmar0/devices
/sys/devices/virtual/iommu/dmar0/devices/0000:00:02.0
/sys/devices/virtual/iommu/dmar0/intel-iommu
/sys/devices/virtual/iommu/dmar0/intel-iommu/cap
/sys/devices/virtual/iommu/dmar0/intel-iommu/ecap
/sys/devices/virtual/iommu/dmar0/intel-iommu/address
/sys/devices/virtual/iommu/dmar0/intel-iommu/version
/sys/devices/virtual/iommu/dmar1
/sys/devices/virtual/iommu/dmar1/devices
/sys/devices/virtual/iommu/dmar1/devices/0000:00:00.0
/sys/devices/virtual/iommu/dmar1/devices/0000:00:01.0
/sys/devices/virtual/iommu/dmar1/devices/0000:00:16.0
/sys/devices/virtual/iommu/dmar1/devices/0000:00:1a.0
/sys/devices/virtual/iommu/dmar1/devices/0000:00:1b.0
/sys/devices/virtual/iommu/dmar1/devices/0000:00:1c.0
...
/sys/devices/virtual/iommu/dmar1/intel-iommu
/sys/devices/virtual/iommu/dmar1/intel-iommu/cap
/sys/devices/virtual/iommu/dmar1/intel-iommu/ecap
/sys/devices/virtual/iommu/dmar1/intel-iommu/address
/sys/devices/virtual/iommu/dmar1/intel-iommu/version
/sys/class/iommu/dmar0
/sys/class/iommu/dmar1
(devices also link back to the dmar units)
This makes address, version, capabilities, and extended capabilities
available, just like printed on boot. I've tried not to duplicate
data that can be found in the DMAR table, with the exception of the
address, which provides an easy way to associate the sysfs device with
a DRHD entry in the DMAR. It's tempting to add scopes and RMRR data
here, but the full DMAR table is already exposed under /sys/firmware/
and therefore already provides a way for userspace to learn such
details.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Functions alloc_iommu() and parse_ioapics_under_ir()
are only used internally, so mark them as static.
[Joerg: Made detect_intel_iommu() non-static again for IA64]
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Currently Intel interrupt remapping drivers uses the "present" flag bit
in remapping entry to track whether an entry is allocated or not.
It works as follow:
1) allocate a remapping entry and set its "present" flag bit to 1
2) compose other fields for the entry
3) update the remapping entry with the composed value
The remapping hardware may access the entry between step 1 and step 3,
which then observers an entry with the "present" flag set but random
values in all other fields.
This patch introduces a dedicated bitmap to track remapping entry
allocation status instead of sharing the "present" flag with hardware,
thus eliminate the race window. It also simplifies the implementation.
Tested-and-reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
