Commit Graph

49 Commits

Author SHA1 Message Date
Lu Baolu
0bbeb01a4f iommu/vt-d: Manage scalalble mode PASID tables
In scalable mode, pasid structure is a two level table with
a pasid directory table and a pasid table. Any pasid entry
can be identified by a pasid value in below way.

   1
   9                       6 5      0
    .-----------------------.-------.
    |              PASID    |       |
    '-----------------------'-------'    .-------------.
             |                    |      |             |
             |                    |      |             |
             |                    |      |             |
             |     .-----------.  |      .-------------.
             |     |           |  |----->| PASID Entry |
             |     |           |  |      '-------------'
             |     |           |  |Plus  |             |
             |     .-----------.  |      |             |
             |---->| DIR Entry |-------->|             |
             |     '-----------'         '-------------'
.---------.  |Plus |           |
| Context |  |     |           |
|  Entry  |------->|           |
'---------'        '-----------'

This changes the pasid table APIs to support scalable mode
PASID directory and PASID table. It also adds a helper to
get the PASID table entry according to the pasid value.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-12-11 10:45:57 +01:00
Michal Hocko
4e15a073a1 Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"
Revert 5ff7091f5a ("mm, mmu_notifier: annotate mmu notifiers with
blockable invalidate callbacks").

MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no
longer needed since 93065ac753 ("mm, oom: distinguish blockable mode for
mmu notifiers").  We now have a full support for per range !blocking
behavior so we can drop the stop gap workaround which the per notifier
flag was used for.

Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:19 -07:00
Linus Torvalds
18b8bfdfba IOMMU Update for Linux v4.19
Including:
 
 	- PASID table handling updates for the Intel VT-d driver. It
 	  implements a global PASID space now so that applications
 	  usings multiple devices will just have one PASID.
 
 	- A new config option to make iommu passthroug mode the default.
 
 	- New sysfs attribute for iommu groups to export the type of the
 	  default domain.
 
 	- A debugfs interface (for debug only) usable by IOMMU drivers
 	  to export internals to user-space.
 
 	- R-Car Gen3 SoCs support for the ipmmu-vmsa driver
 
 	- The ARM-SMMU now aborts transactions from unknown devices and
 	  devices not attached to any domain.
 
 	- Various cleanups and smaller fixes all over the place.
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Merge tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:

 - PASID table handling updates for the Intel VT-d driver. It implements
   a global PASID space now so that applications usings multiple devices
   will just have one PASID.

 - A new config option to make iommu passthroug mode the default.

 - New sysfs attribute for iommu groups to export the type of the
   default domain.

 - A debugfs interface (for debug only) usable by IOMMU drivers to
   export internals to user-space.

 - R-Car Gen3 SoCs support for the ipmmu-vmsa driver

 - The ARM-SMMU now aborts transactions from unknown devices and devices
   not attached to any domain.

 - Various cleanups and smaller fixes all over the place.

* tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (42 commits)
  iommu/omap: Fix cache flushes on L2 table entries
  iommu: Remove the ->map_sg indirection
  iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel
  iommu/arm-smmu-v3: Prevent any devices access to memory without registration
  iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA
  iommu/ipmmu-vmsa: Clarify supported platforms
  iommu/ipmmu-vmsa: Fix allocation in atomic context
  iommu: Add config option to set passthrough as default
  iommu: Add sysfs attribyte for domain type
  iommu/arm-smmu-v3: sync the OVACKFLG to PRIQ consumer register
  iommu/arm-smmu: Error out only if not enough context interrupts
  iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE
  iommu/io-pgtable-arm: Fix pgtable allocation in selftest
  iommu/vt-d: Remove the obsolete per iommu pasid tables
  iommu/vt-d: Apply per pci device pasid table in SVA
  iommu/vt-d: Allocate and free pasid table
  iommu/vt-d: Per PCI device pasid table interfaces
  iommu/vt-d: Add for_each_device_domain() helper
  iommu/vt-d: Move device_domain_info to header
  iommu/vt-d: Apply global PASID in SVA
  ...
2018-08-24 13:10:38 -07:00
Souptick Joarder
50a7ca3c6f mm: convert return type of handle_mm_fault() caller to vm_fault_t
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Lu Baolu
d9737953d8 iommu/vt-d: Remove the obsolete per iommu pasid tables
The obsolete per iommu pasid tables are no longer used. Hence,
clean up them.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-20 14:44:26 +02:00
Lu Baolu
4774cc5245 iommu/vt-d: Apply per pci device pasid table in SVA
This patch applies the per pci device pasid table in the Shared
Virtual Address (SVA) implementation.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-20 14:44:25 +02:00
Lu Baolu
cc580e4126 iommu/vt-d: Per PCI device pasid table interfaces
This patch adds the interfaces for per PCI device pasid
table management. Currently we allocate one pasid table
for all PCI devices under the scope of an IOMMU. It's
insecure in some cases where multiple devices under one
single IOMMU unit support PASID features. With per PCI
device pasid table, we can achieve finer protection and
isolation granularity.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-20 14:44:24 +02:00
Lu Baolu
af39507305 iommu/vt-d: Apply global PASID in SVA
This patch applies the global pasid name space in the shared
virtual address (SVA) implementation.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-20 14:44:24 +02:00
Lu Baolu
51261aac51 iommu/vt-d: Avoid using idr_for_each_entry()
idr_for_each_entry() is used to iteratte over idr elements
of a given type. It isn't suitable for the globle pasid idr
since the pasid idr consumer could specify different types
of pointers to bind with a pasid.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-20 14:44:23 +02:00
Lu Baolu
3e781fcafe iommu/vt-d: Remove unnecessary WARN_ON()
When drivers call intel_svm_available() to check whether the
Shared Virtual Memory(SVM) is supported by the IOMMU driver,
they will get a warning in the kernel message if the SVM is
not supported by the hardware.

[    3.790876] WARNING: CPU: 0 PID: 267 at drivers/iommu/intel-svm.c:334 intel_svm_bind_mm+0x292/0x570
[    3.790877] Modules linked in: dsa(+) vfio_mdev mdev vfio_iommu_type1 soundcore vfio serio_raw parport_pc ppdev lp parport autofs4 psmouse virtio_net pata_acpi
[    3.790884] CPU: 0 PID: 267 Comm: systemd-udevd Not tainted 4.15.0+ #358
[    3.790885] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
[    3.790887] RIP: 0010:intel_svm_bind_mm+0x292/0x570
[    3.790887] RSP: 0000:ffffac72c08a3a70 EFLAGS: 00010246
[    3.790889] RAX: 0000000000000000 RBX: ffff90447a5160a0 RCX: 0000000000000000
[    3.790889] RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff90447fc16550
[    3.790890] RBP: ffff90447a516000 R08: 0000000000000000 R09: 0000000000000178
[    3.790891] R10: 0000000000000220 R11: 0000000000aaaaaa R12: 0000000000000000
[    3.790891] R13: 0000000000000002 R14: ffffac72c08a3b18 R15: ffffac72c08a3eb8
[    3.790893] FS:  00007fb21e85b8c0(0000) GS:ffff90447fc00000(0000) knlGS:0000000000000000
[    3.790894] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.790894] CR2: 000055c08167d148 CR3: 000000013a6f4000 CR4: 00000000000006f0
[    3.790903] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    3.790904] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

This is caused by a unnecessary WARN_ON() in intel_svm_bind_mm().
Hence, remove it.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-07-06 14:18:20 +02:00
Lu Baolu
bb37f7db07 iommu/vt-d: Remove unnecessary parentheses
Remove unnecessary parentheses to comply with preferred coding
style.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-05-15 16:34:53 +02:00
Joerg Roedel
d4f96fd5c2 Merge branches 'x86/amd', 'x86/vt-d', 'arm/rockchip', 'arm/omap', 'arm/mediatek', 'arm/exynos', 'arm/renesas', 'arm/smmu' and 'core' into next 2018-03-29 15:24:40 +02:00
Lu Baolu
971401015d iommu/vt-d: Use real PASID for flush in caching mode
If caching mode is supported, the hardware will cache
none-present or erroneous translation entries. Hence,
software should explicitly invalidate the PASID cache
after a PASID table entry becomes present. We should
issue such invalidation with the PASID value that we
have changed. PASID 0 is not reserved for this case.

Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Sankaran Rajesh <rajesh.sankaran@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-03-20 13:43:27 -05:00
Lu Baolu
bbe4b3af9d iommu/vt-d: Fix a potential memory leak
A memory block was allocated in intel_svm_bind_mm() but never freed
in a failure path. This patch fixes this by free it to avoid memory
leakage.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Fixes: 2f26e0a9c9 ('iommu/vt-d: Add basic SVM PASID support')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-03-15 15:15:22 +01:00
Ingo Molnar
ed7158bae4 treewide/trivial: Remove ';;$' typo noise
On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:

  --- a/arch/x86/boot/compressed/eboot.c
  +++ b/arch/x86/boot/compressed/eboot.c
  @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
          struct efi_uga_draw_protocol *uga = NULL, *first_uga;
          efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
          unsigned long nr_ugas;
  -       u32 *handles = (u32 *)uga_handle;;
  +       u32 *handles = (u32 *)uga_handle;
          efi_status_t status = EFI_INVALID_PARAMETER;
          int i;

This patch is the result of the following script:

  $ sed -i 's/;;$/;/g' $(git grep -E ';;$'  | grep "\.[ch]:"  | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)

... followed by manual review to make sure it's all good.

Splitting this up is just crazy talk, let's get over with this and just do it.

Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-22 10:59:33 +01:00
Linus Torvalds
ef9417e8a9 IOMMU Updates for Linux v4.16
Including:
 
 	- 5-level page-table support for the Intel IOMMU.
 
 	- Error reporting improvements for the AMD IOMMU driver
 
 	- Additional DT bindings for ipmmu-vmsa (Renesas)
 
 	- Smaller fixes and cleanups
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Merge tag 'iommu-updates-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "This time there are not a lot of changes coming from the IOMMU side.

  That is partly because I returned from my parental leave late in the
  development process and probably partly because everyone was busy with
  Spectre and Meltdown mitigation work and didn't find the time for
  IOMMU work. So here are the few changes that queued up for this merge
  window:

   - 5-level page-table support for the Intel IOMMU.

   - error reporting improvements for the AMD IOMMU driver

   - additional DT bindings for ipmmu-vmsa (Renesas)

   - small fixes and cleanups"

* tag 'iommu-updates-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: Clean up of_iommu_init_fn
  iommu/ipmmu-vmsa: Remove redundant of_iommu_init_fn hook
  iommu/msm: Claim bus ops on probe
  iommu/vt-d: Enable 5-level paging mode in the PASID entry
  iommu/vt-d: Add a check for 5-level paging support
  iommu/vt-d: Add a check for 1GB page support
  iommu/vt-d: Enable upto 57 bits of domain address width
  iommu/vt-d: Use domain instead of cache fetching
  iommu/exynos: Don't unconditionally steal bus ops
  iommu/omap: Fix debugfs_create_*() usage
  iommu/vt-d: clean up pr_irq if request_threaded_irq fails
  iommu: Check the result of iommu_group_get() for NULL
  iommu/ipmmu-vmsa: Add r8a779(70|95) DT bindings
  iommu/ipmmu-vmsa: Add r8a7796 DT binding
  iommu/amd: Set the device table entry PPR bit for IOMMU V2 devices
  iommu/amd - Record more information about unknown events
2018-02-08 12:03:54 -08:00
David Rientjes
5ff7091f5a mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks
Commit 4d4bbd8526 ("mm, oom_reaper: skip mm structs with mmu
notifiers") prevented the oom reaper from unmapping private anonymous
memory with the oom reaper when the oom victim mm had mmu notifiers
registered.

The rationale is that doing mmu_notifier_invalidate_range_{start,end}()
around the unmap_page_range(), which is needed, can block and the oom
killer will stall forever waiting for the victim to exit, which may not
be possible without reaping.

That concern is real, but only true for mmu notifiers that have
blockable invalidate_range_{start,end}() callbacks.  This patch adds a
"flags" field to mmu notifier ops that can set a bit to indicate that
these callbacks do not block.

The implementation is steered toward an expensive slowpath, such as
after the oom reaper has grabbed mm->mmap_sem of a still alive oom
victim.

[rientjes@google.com: mmu_notifier_invalidate_range_end() can also call the invalidate_range() must not block, fix comment]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801091339570.240101@chino.kir.corp.google.com
[akpm@linux-foundation.org: make mm_has_blockable_invalidate_notifiers() return bool, use rwsem_is_locked()]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141329500.74052@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:38 -08:00
Sohil Mehta
2f13eb7c58 iommu/vt-d: Enable 5-level paging mode in the PASID entry
If the CPU has support for 5-level paging enabled and the IOMMU also
supports 5-level paging then enable the 5-level paging mode for first-
level translations - used when SVM is enabled.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-01-17 15:02:50 +01:00
Sohil Mehta
f1ac10c24e iommu/vt-d: Add a check for 5-level paging support
Add a check to verify IOMMU 5-level paging support. If the CPU supports
supports 5-level paging but the IOMMU does not support it then disable
SVM by not allocating PASID tables.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-01-17 15:02:50 +01:00
Sohil Mehta
59103caa68 iommu/vt-d: Add a check for 1GB page support
Add a check to verify IOMMU 1GB page support. If the CPU supports 1GB
pages but the IOMMU does not support it then disable SVM by not
allocating PASID tables.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-01-17 15:02:50 +01:00
Jerry Snitselaar
72d5481138 iommu/vt-d: clean up pr_irq if request_threaded_irq fails
It is unlikely request_threaded_irq will fail, but if it does for some
reason we should clear iommu->pr_irq in the error path. Also
intel_svm_finish_prq shouldn't try to clean up the page request
interrupt if pr_irq is 0. Without these, if request_threaded_irq were
to fail the following occurs:

fail with no fixes:

[    0.683147] ------------[ cut here ]------------
[    0.683148] NULL pointer, cannot free irq
[    0.683158] WARNING: CPU: 1 PID: 1 at kernel/irq/irqdomain.c:1632 irq_domain_free_irqs+0x126/0x140
[    0.683160] Modules linked in:
[    0.683163] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #3
[    0.683165] Hardware name:                  /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017
[    0.683168] RIP: 0010:irq_domain_free_irqs+0x126/0x140
[    0.683169] RSP: 0000:ffffc90000037ce8 EFLAGS: 00010292
[    0.683171] RAX: 000000000000001d RBX: ffff880276283c00 RCX: ffffffff81c5e5e8
[    0.683172] RDX: 0000000000000001 RSI: 0000000000000096 RDI: 0000000000000246
[    0.683174] RBP: ffff880276283c00 R08: 0000000000000000 R09: 000000000000023c
[    0.683175] R10: 0000000000000007 R11: 0000000000000000 R12: 000000000000007a
[    0.683176] R13: 0000000000000001 R14: 0000000000000000 R15: 0000010010000000
[    0.683178] FS:  0000000000000000(0000) GS:ffff88027ec80000(0000) knlGS:0000000000000000
[    0.683180] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.683181] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0
[    0.683182] Call Trace:
[    0.683189]  intel_svm_finish_prq+0x3c/0x60
[    0.683191]  free_dmar_iommu+0x1ac/0x1b0
[    0.683195]  init_dmars+0xaaa/0xaea
[    0.683200]  ? klist_next+0x19/0xc0
[    0.683203]  ? pci_do_find_bus+0x50/0x50
[    0.683205]  ? pci_get_dev_by_id+0x52/0x70
[    0.683208]  intel_iommu_init+0x498/0x5c7
[    0.683211]  pci_iommu_init+0x13/0x3c
[    0.683214]  ? e820__memblock_setup+0x61/0x61
[    0.683217]  do_one_initcall+0x4d/0x1a0
[    0.683220]  kernel_init_freeable+0x186/0x20e
[    0.683222]  ? set_debug_rodata+0x11/0x11
[    0.683225]  ? rest_init+0xb0/0xb0
[    0.683226]  kernel_init+0xa/0xff
[    0.683229]  ret_from_fork+0x1f/0x30
[    0.683259] Code: 89 ee 44 89 e7 e8 3b e8 ff ff 5b 5d 44 89 e7 44 89 ee 41 5c 41 5d 41 5e e9 a8 84 ff ff 48 c7 c7 a8 71 a7 81 31 c0 e8 6a d3 f9 ff <0f> ff 5b 5d 41 5c 41 5d 41 5
e c3 0f 1f 44 00 00 66 2e 0f 1f 84
[    0.683285] ---[ end trace f7650e42792627ca ]---

with iommu->pr_irq = 0, but no check in intel_svm_finish_prq:

[    0.669561] ------------[ cut here ]------------
[    0.669563] Trying to free already-free IRQ 0
[    0.669573] WARNING: CPU: 3 PID: 1 at kernel/irq/manage.c:1546 __free_irq+0xa4/0x2c0
[    0.669574] Modules linked in:
[    0.669577] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #4
[    0.669579] Hardware name:                  /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017
[    0.669581] RIP: 0010:__free_irq+0xa4/0x2c0
[    0.669582] RSP: 0000:ffffc90000037cc0 EFLAGS: 00010082
[    0.669584] RAX: 0000000000000021 RBX: 0000000000000000 RCX: ffffffff81c5e5e8
[    0.669585] RDX: 0000000000000001 RSI: 0000000000000086 RDI: 0000000000000046
[    0.669587] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000023c
[    0.669588] R10: 0000000000000007 R11: 0000000000000000 R12: ffff880276253960
[    0.669589] R13: ffff8802762538a4 R14: ffff880276253800 R15: ffff880276283600
[    0.669593] FS:  0000000000000000(0000) GS:ffff88027ed80000(0000) knlGS:0000000000000000
[    0.669594] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.669596] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0
[    0.669602] Call Trace:
[    0.669616]  free_irq+0x30/0x60
[    0.669620]  intel_svm_finish_prq+0x34/0x60
[    0.669623]  free_dmar_iommu+0x1ac/0x1b0
[    0.669627]  init_dmars+0xaaa/0xaea
[    0.669631]  ? klist_next+0x19/0xc0
[    0.669634]  ? pci_do_find_bus+0x50/0x50
[    0.669637]  ? pci_get_dev_by_id+0x52/0x70
[    0.669639]  intel_iommu_init+0x498/0x5c7
[    0.669642]  pci_iommu_init+0x13/0x3c
[    0.669645]  ? e820__memblock_setup+0x61/0x61
[    0.669648]  do_one_initcall+0x4d/0x1a0
[    0.669651]  kernel_init_freeable+0x186/0x20e
[    0.669653]  ? set_debug_rodata+0x11/0x11
[    0.669656]  ? rest_init+0xb0/0xb0
[    0.669658]  kernel_init+0xa/0xff
[    0.669661]  ret_from_fork+0x1f/0x30
[    0.669662] Code: 7a 08 75 0e e9 c3 01 00 00 4c 39 7b 08 74 57 48 89 da 48 8b 5a 18 48 85 db 75 ee 89 ee 48 c7 c7 78 67 a7 81 31 c0 e8 4c 37 fa ff <0f> ff 48 8b 34 24 4c 89 ef e
8 0e 4c 68 00 49 8b 46 40 48 8b 80
[    0.669688] ---[ end trace 58a470248700f2fc ]---

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-12-20 09:48:56 -07:00
Lu Baolu
4fa064b26c iommu/vt-d: Clear pasid table entry when memory unbound
In intel_svm_unbind_mm(), pasid table entry must be cleared during
svm free. Otherwise, hardware may be set up with a wild pointer.

Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-11-03 10:51:34 -06:00
Lu Baolu
2e2e35d512 iommu/vt-d: Missing checks for pasid tables if allocation fails
intel_svm_alloc_pasid_tables() might return an error but never be
checked by the callers. Later when intel_svm_bind_mm() is called,
there are no checks for valid pasid tables before enabling them.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Liu, Yi L <yi.l.liu@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-11-03 10:51:32 -06:00
Linus Torvalds
4dfc278803 IOMMU Updates for Linux v4.14
Slightly more changes than usual this time:
 
 	- KDump Kernel IOMMU take-over code for AMD IOMMU. The code now
 	  tries to preserve the mappings of the kernel so that master
 	  aborts for devices are avoided. Master aborts cause some
 	  devices to fail in the kdump kernel, so this code makes the
 	  dump more likely to succeed when AMD IOMMU is enabled.
 
 	- Common flush queue implementation for IOVA code users. The
 	  code is still optional, but AMD and Intel IOMMU drivers had
 	  their own implementation which is now unified.
 
 	- Finish support for iommu-groups. All drivers implement this
 	  feature now so that IOMMU core code can rely on it.
 
 	- Finish support for 'struct iommu_device' in iommu drivers. All
 	  drivers now use the interface.
 
 	- New functions in the IOMMU-API for explicit IO/TLB flushing.
 	  This will help to reduce the number of IO/TLB flushes when
 	  IOMMU drivers support this interface.
 
 	- Support for mt2712 in the Mediatek IOMMU driver
 
 	- New IOMMU driver for QCOM hardware
 
 	- System PM support for ARM-SMMU
 
 	- Shutdown method for ARM-SMMU-v3
 
 	- Some constification patches
 
 	- Various other small improvements and fixes
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Merge tag 'iommu-updates-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "Slightly more changes than usual this time:

   - KDump Kernel IOMMU take-over code for AMD IOMMU. The code now tries
     to preserve the mappings of the kernel so that master aborts for
     devices are avoided. Master aborts cause some devices to fail in
     the kdump kernel, so this code makes the dump more likely to
     succeed when AMD IOMMU is enabled.

   - common flush queue implementation for IOVA code users. The code is
     still optional, but AMD and Intel IOMMU drivers had their own
     implementation which is now unified.

   - finish support for iommu-groups. All drivers implement this feature
     now so that IOMMU core code can rely on it.

   - finish support for 'struct iommu_device' in iommu drivers. All
     drivers now use the interface.

   - new functions in the IOMMU-API for explicit IO/TLB flushing. This
     will help to reduce the number of IO/TLB flushes when IOMMU drivers
     support this interface.

   - support for mt2712 in the Mediatek IOMMU driver

   - new IOMMU driver for QCOM hardware

   - system PM support for ARM-SMMU

   - shutdown method for ARM-SMMU-v3

   - some constification patches

   - various other small improvements and fixes"

* tag 'iommu-updates-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (87 commits)
  iommu/vt-d: Don't be too aggressive when clearing one context entry
  iommu: Introduce Interface for IOMMU TLB Flushing
  iommu/s390: Constify iommu_ops
  iommu/vt-d: Avoid calling virt_to_phys() on null pointer
  iommu/vt-d: IOMMU Page Request needs to check if address is canonical.
  arm/tegra: Call bus_set_iommu() after iommu_device_register()
  iommu/exynos: Constify iommu_ops
  iommu/ipmmu-vmsa: Make ipmmu_gather_ops const
  iommu/ipmmu-vmsa: Rereserving a free context before setting up a pagetable
  iommu/amd: Rename a few flush functions
  iommu/amd: Check if domain is NULL in get_domain() and return -EBUSY
  iommu/mediatek: Fix a build warning of BIT(32) in ARM
  iommu/mediatek: Fix a build fail of m4u_type
  iommu: qcom: annotate PM functions as __maybe_unused
  iommu/pamu: Fix PAMU boot crash
  memory: mtk-smi: Degrade SMI init to module_init
  iommu/mediatek: Enlarge the validate PA range for 4GB mode
  iommu/mediatek: Disable iommu clock when system suspend
  iommu/mediatek: Move pgtable allocation into domain_alloc
  iommu/mediatek: Merge 2 M4U HWs into one iommu domain
  ...
2017-09-09 15:03:24 -07:00
Jérôme Glisse
30ef7d2c05 iommu/intel: update to new mmu_notifier semantic
Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-31 16:12:59 -07:00
Ashok Raj
9d8c3af316 iommu/vt-d: IOMMU Page Request needs to check if address is canonical.
Page Request from devices that support device-tlb would request translation
to pre-cache them in device to avoid overhead of IOMMU lookups.

IOMMU needs to check for canonicallity of the address before performing
page-fault processing.

To: Joerg Roedel <joro@8bytes.org>
To: linux-kernel@vger.kernel.org>
Cc: iommu@lists.linux-foundation.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Reported-by: Sudeep Dutt <sudeep.dutt@intel.com>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-08-30 17:48:18 +02:00
CQ Tang
15060aba71 iommu/vt-d: Helper function to query if a pasid has any active users
A driver would need to know if there are any active references to a
a PASID before cleaning up its resources. This function helps check
if there are any active users of a PASID before it can perform any
recovery on that device.

To: Joerg Roedel <joro@8bytes.org>
To: linux-kernel@vger.kernel.org
To: David Woodhouse <dwmw2@infradead.org>
Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
Cc: iommu@lists.linux-foundation.org

Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-05-17 14:57:56 +02:00
Ingo Molnar
6e84f31522 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/mm.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

The APIs that are going to be moved first are:

   mm_alloc()
   __mmdrop()
   mmdrop()
   mmdrop_async_fn()
   mmdrop_async()
   mmget_not_zero()
   mmput()
   mmput_async()
   get_task_mm()
   mm_access()
   mm_release()

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:28 +01:00
Vegard Nossum
388f793455 mm: use mmget_not_zero() helper
We already have the helper, we can convert the rest of the kernel
mechanically using:

  git grep -l 'atomic_inc_not_zero.*mm_users' | xargs sed -i 's/atomic_inc_not_zero(&\(.*\)->mm_users)/mmget_not_zero\(\1\)/'

This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.

Link: http://lkml.kernel.org/r/20161218123229.22952-3-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:48 -08:00
David Woodhouse
9101704429 iommu/vt-d: Fix PASID table allocation
Somehow I ended up with an off-by-three error in calculating the size of
the PASID and PASID State tables, which triggers allocations failures as
those tables unfortunately have to be physically contiguous.

In fact, even the *correct* maximum size of 8MiB is problematic and is
wont to lead to allocation failures. Since I have extracted a promise
that this *will* be fixed in hardware, I'm happy to limit it on the
current hardware to a maximum of 0x20000 PASIDs, which gives us 1MiB
tables — still not ideal, but better than before.

Reported by Mika Kuoppala <mika.kuoppala@linux.intel.com> and also by
Xunlei Pang <xlpang@redhat.com> who submitted a simpler patch to fix
only the allocation (and not the free) to the "correct" limit... which
was still problematic.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: stable@vger.kernel.org
2016-11-19 09:42:35 -08:00
Kirill A. Shutemov
dcddffd41d mm: do not pass mm_struct into handle_mm_fault
We always have vma->vm_mm around.

Link: http://lkml.kernel.org/r/1466021202-61880-8-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
David Woodhouse
4692400827 iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts
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
2016-02-15 12:42:38 +00:00
David Woodhouse
e57e58bd39 iommu/vt-d: Fix mm refcounting to hold mm_count not mm_users
Holding mm_users works OK for graphics, which was the first user of SVM
with VT-d. However, it works less well for other devices, where we actually
do a mmap() from the file descriptor to which the SVM PASID state is tied.

In this case on process exit we end up with a recursive reference count:
 - The MM remains alive until the file is closed and the driver's release()
   call ends up unbinding the PASID.
 - The VMA corresponding to the mmap() remains intact until the MM is
   destroyed.
 - Thus the file isn't closed, even when exit_files() runs, because the
   VMA is still holding a reference to it. And the MM remains alive…

To address this issue, we *stop* holding mm_users while the PASID is bound.
We already hold mm_count by virtue of the MMU notifier, and that can be
made to be sufficient.

It means that for a period during process exit, the fun part of mmput()
has happened and exit_mmap() has been called so the MM is basically
defunct. But the PGD still exists and the PASID is still bound to it.

During this period, we have to be very careful — exit_mmap() doesn't use
mm->mmap_sem because it doesn't expect anyone else to be touching the MM
(quite reasonably, since mm_users is zero). So we also need to fix the
fault handler to just report failure if mm_users is already zero, and to
temporarily bump mm_users while handling any faults.

Additionally, exit_mmap() calls mmu_notifier_release() *before* it tears
down the page tables, which is too early for us to flush the IOTLB for
this PASID. And __mmu_notifier_release() removes every notifier from the
list, so when exit_mmap() finally *does* tear down the mappings and
clear the page tables, we don't get notified. So we work around this by
clearing the PASID table entry in our MMU notifier release() callback.
That way, the hardware *can't* get any pages back from the page tables
before they get cleared.

Hardware designers have confirmed that the resulting 'PASID not present'
faults should be handled just as gracefully as 'page not present' faults,
the important criterion being that they don't perturb the operation for
any *other* PASID in the system.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@vger.kernel.org
2016-01-13 21:05:46 +00:00
Joerg Roedel
7f8312a3b3 iommu/vt-d: Do access checks before calling handle_mm_fault()
Not doing so is a bug and might trigger a BUG_ON in
handle_mm_fault(). So add the proper permission checks
before calling into mm code.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-12-14 15:37:55 +01:00
David Woodhouse
0bdec95ce5 iommu/vt-d: Fix rwxp flags in SVM device fault callback
This is the downside of using bitfields in the struct definition, rather
than doing all the explicit masking and shifting.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-28 15:14:09 +09:00
David Woodhouse
5a10ba27d9 iommu/vt-d: Handle Caching Mode implementations of SVM
Not entirely clear why, but it seems we need to reserve PASID zero and
flush it when we make a PASID entry present.

Quite we we couldn't use the true PASID value, isn't clear.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-24 21:06:39 +02:00
David Woodhouse
5d52f482eb iommu/vt-d: Fix SVM IOTLB flush handling
Change the 'pages' parameter to 'unsigned long' to avoid overflow.

Fix the device-IOTLB flush parameter calculation — the size of the IOTLB
flush is indicated by the position of the least significant zero bit in
the address field. For example, a value of 0x12345f000 will flush from
0x123440000 to 0x12347ffff (256KiB).

Finally, the cap_pgsel_inv() is not relevant to SVM; the spec says that
*all* implementations must support page-selective invaliation for
"first-level" translations. So don't check for it.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-20 16:26:21 +01:00
Dan Carpenter
3c7c2f3288 iommu/vt-d: fix a loop in prq_event_thread()
There is an extra semi-colon on this if statement so we always break on
the first iteration.

Fixes: 0204a49609 ('iommu/vt-d: Add callback to device driver on page faults')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-18 15:26:04 +01:00
David Woodhouse
e034992160 iommu/vt-d: Fix IOTLB flushing for global pages
When flushing kernel-mode PASIDs, we need to flush global pages too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-16 19:37:04 +01:00
David Woodhouse
7f92a2e910 iommu/vt-d: Fix address shifting in page request handler
This really should be VTD_PAGE_SHIFT, not PAGE_SHIFT. Not that we ever
really anticipate seeing this used on IA64, but we should get it right
anyway.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-16 17:22:34 +01:00
Dan Carpenter
95fb6144bb iommu/vt-d: shift wrapping bug in prq_event_thread()
The "req->addr" variable is a bit field declared as "u64 addr:52;".
The "address" variable is a u64.  We need to cast "req->addr" to a u64
before the shift or the result is truncated to 52 bits.

Fixes: a222a7f0bb ('iommu/vt-d: Implement page request handling')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 21:16:47 +01:00
David Woodhouse
26322ab55a iommu/vt-d: Fix NULL pointer dereference in page request error case
Dan Carpenter pointed out an error path which could lead to us
dereferencing the 'svm' pointer after we know it to be NULL because the
PASID lookup failed. Fix that, and make it less likely to happen again.

Fixes: a222a7f0bb ('iommu/vt-d: Implement page request handling')
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 21:16:22 +01:00
David Woodhouse
5cec753709 iommu/vt-d: Implement SVM_FLAG_SUPERVISOR_MODE for kernel access
This is only usable for the static 1:1 mapping of physical memory.

Any access to vmalloc or module regions will require some way of doing
an IOTLB flush. It's theoretically possible to hook into the
tlb_flush_kernel_range() function, but that seems like overkill — most
of the addresses accessed through a kernel PASID *will* be in the 1:1
mapping.

If we really need to allow access to more interesting kernel regions,
then the answer will probably be an explicit IOTLB flush call after use,
akin to the DMA API's unmap function.

In fact, it might be worth introducing that sooner rather than later, and
making it just BUG() if the address isn't in the static 1:1 mapping.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 15:52:21 +01:00
David Woodhouse
569e4f7782 iommu/vt-d: Implement SVM_FLAG_PRIVATE_PASID to allocate unique PASIDs
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 15:35:32 +01:00
David Woodhouse
0204a49609 iommu/vt-d: Add callback to device driver on page faults
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 15:35:28 +01:00
David Woodhouse
a222a7f0bb iommu/vt-d: Implement page request handling
Largely based on the driver-mode implementation by Jesse Barnes.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 15:35:19 +01:00
David Woodhouse
907fea3491 iommu/vt-d: Implement deferred invalidate for SVM
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 13:22:35 +01:00
David Woodhouse
2f26e0a9c9 iommu/vt-d: Add basic SVM PASID support
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>
2015-10-15 12:55:45 +01:00
David Woodhouse
8a94ade4ce iommu/vt-d: Add initial support for PASID tables
Add CONFIG_INTEL_IOMMU_SVM, and allocate PASID tables on supported hardware.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2015-10-15 11:24:51 +01:00