14 Commits

Author SHA1 Message Date
Aditya Srivastava
367f82de5a iommu/vt-d: Fix kernel-doc syntax in file header
The opening comment mark '/**' is used for highlighting the beginning of
kernel-doc comments.
The header for drivers/iommu/intel/pasid.c follows this syntax, but
the content inside does not comply with kernel-doc.

This line was probably not meant for kernel-doc parsing, but is parsed
due to the presence of kernel-doc like comment syntax(i.e, '/**'), which
causes unexpected warnings from kernel-doc:
warning: Function parameter or member 'fmt' not described in 'pr_fmt'

Provide a simple fix by replacing this occurrence with general comment
format, i.e. '/*', to prevent kernel-doc from parsing it.

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210523143245.19040-1-yashsri421@gmail.com
Link: https://lore.kernel.org/r/20210610020115.1637656-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-06-10 09:06:12 +02:00
Lu Baolu
54c80d9074 iommu/vt-d: Use user privilege for RID2PASID translation
When first-level page tables are used for IOVA translation, we use user
privilege by setting U/S bit in the page table entry. This is to make it
consistent with the second level translation, where the U/S enforcement
is not available. Clear the SRE (Supervisor Request Enable) field in the
pasid table entry of RID2PASID so that requests requesting the supervisor
privilege are blocked and treated as DMA remapping faults.

Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level")
Suggested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210512064426.3440915-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210519015027.108468-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-05-19 08:51:02 +02:00
Lu Baolu
906f86c860 iommu/vt-d: Fix build error of pasid_enable_wpe() with !X86
Commit f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor
SVM") added pasid_enable_wpe() which hit below compile error with !X86.

../drivers/iommu/intel/pasid.c: In function 'pasid_enable_wpe':
../drivers/iommu/intel/pasid.c:554:22: error: implicit declaration of function 'read_cr0' [-Werror=implicit-function-declaration]
  554 |  unsigned long cr0 = read_cr0();
      |                      ^~~~~~~~
In file included from ../include/linux/build_bug.h:5,
                 from ../include/linux/bits.h:22,
                 from ../include/linux/bitops.h:6,
                 from ../drivers/iommu/intel/pasid.c:12:
../drivers/iommu/intel/pasid.c:557:23: error: 'X86_CR0_WP' undeclared (first use in this function)
  557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
      |                       ^~~~~~~~~~
../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
   78 | # define unlikely(x) __builtin_expect(!!(x), 0)
      |                                          ^
../drivers/iommu/intel/pasid.c:557:23: note: each undeclared identifier is reported only once for each function it appears in
  557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
      |                       ^~~~~~~~~~
../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
   78 | # define unlikely(x) __builtin_expect(!!(x), 0)
      |

Add the missing dependency.

Cc: Sanjay Kumar <sanjay.k.kumar@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor SVM")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20210411062312.3057579-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-04-15 15:43:20 +02:00
Lu Baolu
8b74b6ab25 iommu/vt-d: Avoid unnecessary cache flush in pasid entry teardown
When a present pasid entry is disassembled, all kinds of pasid related
caches need to be flushed. But when a pasid entry is not being used
(PRESENT bit not set), we don't need to do this. Check the PRESENT bit
in intel_pasid_tear_down_entry() and avoid flushing caches if it's not
set.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210320025415.641201-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-04-07 11:55:47 +02:00
Lu Baolu
6c00612d0c iommu/vt-d: Report right snoop capability when using FL for IOVA
The Intel VT-d driver checks wrong register to report snoop capablility
when using first level page table for GPA to HPA translation. This might
lead the IOMMU driver to say that it supports snooping control, but in
reality, it does not. Fix this by always setting PASID-table-entry.PGSNP
whenever a pasid entry is setting up for GPA to HPA translation so that
the IOMMU driver could report snoop capability as long as it runs in the
scalable mode.

Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level")
Suggested-by: Rajesh Sankaran <rajesh.sankaran@intel.com>
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210330021145.13824-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-04-07 10:41:30 +02:00
Lu Baolu
442b81836d iommu/vt-d: Make unnecessarily global functions static
Make some functions static as they are only used inside pasid.c.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210323010600.678627-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-04-07 10:15:58 +02:00
Lu Baolu
803766cbf8 iommu/vt-d: Fix lockdep splat in intel_pasid_get_entry()
The pasid_lock is used to synchronize different threads from modifying a
same pasid directory entry at the same time. It causes below lockdep splat.

[   83.296538] ========================================================
[   83.296538] WARNING: possible irq lock inversion dependency detected
[   83.296539] 5.12.0-rc3+ #25 Tainted: G        W
[   83.296539] --------------------------------------------------------
[   83.296540] bash/780 just changed the state of lock:
[   83.296540] ffffffff82b29c98 (device_domain_lock){..-.}-{2:2}, at:
           iommu_flush_dev_iotlb.part.0+0x32/0x110
[   83.296547] but this lock took another, SOFTIRQ-unsafe lock in the past:
[   83.296547]  (pasid_lock){+.+.}-{2:2}
[   83.296548]

           and interrupts could create inverse lock ordering between them.

[   83.296549] other info that might help us debug this:
[   83.296549] Chain exists of:
                 device_domain_lock --> &iommu->lock --> pasid_lock
[   83.296551]  Possible interrupt unsafe locking scenario:

[   83.296551]        CPU0                    CPU1
[   83.296552]        ----                    ----
[   83.296552]   lock(pasid_lock);
[   83.296553]                                local_irq_disable();
[   83.296553]                                lock(device_domain_lock);
[   83.296554]                                lock(&iommu->lock);
[   83.296554]   <Interrupt>
[   83.296554]     lock(device_domain_lock);
[   83.296555]
                *** DEADLOCK ***

Fix it by replacing the pasid_lock with an atomic exchange operation.

Reported-and-tested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210320020916.640115-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-04-07 10:08:09 +02:00
Jacob Pan
bb0f61533d iommu/vt-d: Enable write protect propagation from guest
Write protect bit, when set, inhibits supervisor writes to the read-only
pages. In guest supervisor shared virtual addressing (SVA), write-protect
should be honored upon guest bind supervisor PASID request.

This patch extends the VT-d portion of the IOMMU UAPI to include WP bit.
WPE bit of the  supervisor PASID entry will be set to match CPU CR0.WP bit.

Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-3-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-18 11:42:46 +01:00
Jacob Pan
f68c7f539b iommu/vt-d: Enable write protect for supervisor SVM
Write protect bit, when set, inhibits supervisor writes to the read-only
pages. In supervisor shared virtual addressing (SVA), where page tables
are shared between CPU and DMA, IOMMU PASID entry WPE bit should match
CR0.WP bit in the CPU.
This patch sets WPE bit for supervisor PASIDs if CR0.WP is set.

Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-2-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-18 11:42:46 +01:00
Lu Baolu
9872f9bd9d iommu/vt-d: Consolidate duplicate cache invaliation code
The pasid based IOTLB and devTLB invalidation code is duplicate in
several places. Consolidate them by using the common helpers.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210114085021.717041-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-01-28 11:30:36 +01:00
Fenghua Yu
c7b6bac9c7 drm, iommu: Change type of pasid to u32
PASID is defined as a few different types in iommu including "int",
"u32", and "unsigned int". To be consistent and to match with uapi
definitions, define PASID and its variations (e.g. max PASID) as "u32".
"u32" is also shorter and a little more explicit than "unsigned int".

No PASID type change in uapi although it defines PASID as __u64 in
some places.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/1600187413-163670-2-git-send-email-fenghua.yu@intel.com
2020-09-17 19:21:16 +02:00
Lu Baolu
02f3effddf iommu/vt-d: Rename intel-pasid.h to pasid.h
As Intel VT-d files have been moved to its own subdirectory, the prefix
makes no sense. No functional changes.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200724014925.15523-13-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-07-24 10:51:21 +02:00
Jacob Pan
e7e69461a8 iommu/vt-d: Fix PASID devTLB invalidation
DevTLB flush can be used for both DMA request with and without PASIDs.
The former uses PASID#0 (RID2PASID), latter uses non-zero PASID for SVA
usage.

This patch adds a check for PASID value such that devTLB flush with
PASID is used for SVA case. This is more efficient in that multiple
PASIDs can be used by a single device, when tearing down a PASID entry
we shall flush only the devTLB specific to a PASID.

Fixes: 6f7db75e1c46 ("iommu/vt-d: Add second level page table")
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200724014925.15523-4-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-07-24 10:51:20 +02:00
Joerg Roedel
672cf6df9b iommu/vt-d: Move Intel IOMMU driver into subdirectory
Move all files related to the Intel IOMMU driver into its own
subdirectory.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200609130303.26974-3-joro@8bytes.org
2020-06-10 17:46:43 +02:00