The CONFIG_ prefix should be added in the code.

Fixes: 04618252 ("iommu/vt-d: Add Kconfig option to enable/disable scalable mode")
Reported-and-tested-by: NKumar, Sanjay K <sanjay.k.kumar@intel.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20200501072427.14265-1-baolu.lu@linux.intel.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

dmar_find_atsr() calls list_for_each_entry_rcu() outside of an RCU read
side critical section but with dmar_global_lock held. Silence this
false positive.

 drivers/iommu/intel-iommu.c:4504 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
 #0: ffffffff9755bee8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x1a6/0xe19

 Call Trace:
  dump_stack+0xa4/0xfe
  lockdep_rcu_suspicious+0xeb/0xf5
  dmar_find_atsr+0x1ab/0x1c0
  dmar_parse_one_atsr+0x64/0x220
  dmar_walk_remapping_entries+0x130/0x380
  dmar_table_init+0x166/0x243
  intel_iommu_init+0x1ab/0xe19
  pci_iommu_init+0x1a/0x44
  do_one_initcall+0xae/0x4d0
  kernel_init_freeable+0x412/0x4c5
  kernel_init+0x19/0x193
Signed-off-by: NQian Cai <cai@lca.pw>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Currently, the intel iommu debugfs directory(/sys/kernel/debug/iommu/intel)
gets populated only when DMA remapping is enabled (dmar_disabled = 0)
irrespective of whether interrupt remapping is enabled or not.

Instead, populate the intel iommu debugfs directory if any IOMMUs are
detected.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: ee2636b8 ("iommu/vt-d: Enable base Intel IOMMU debugfs support")
Signed-off-by: NMegha Dey <megha.dey@linux.intel.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Quoting from the comment describing the WARN functions in
include/asm-generic/bug.h:

 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
 * significant kernel issues that need prompt attention if they should ever
 * appear at runtime.
 *
 * Do not use these macros when checking for invalid external inputs

The (buggy) firmware tables which the dmar code was calling WARN_TAINT
for really are invalid external inputs. They are not under the kernel's
control and the issues in them cannot be fixed by a kernel update.
So logging a backtrace, which invites bug reports to be filed about this,
is not helpful.

Fixes: 556ab45f ("ioat2: catch and recover from broken vtd configurations v6")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200309182510.373875-1-hdegoede@redhat.com
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=701847Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Quoting from the comment describing the WARN functions in
include/asm-generic/bug.h:

 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
 * significant kernel issues that need prompt attention if they should ever
 * appear at runtime.
 *
 * Do not use these macros when checking for invalid external inputs

The (buggy) firmware tables which the dmar code was calling WARN_TAINT
for really are invalid external inputs. They are not under the kernel's
control and the issues in them cannot be fixed by a kernel update.
So logging a backtrace, which invites bug reports to be filed about this,
is not helpful.

Some distros, e.g. Fedora, have tools watching for the kernel backtraces
logged by the WARN macros and offer the user an option to file a bug for
this when these are encountered. The WARN_TAINT in dmar_parse_one_rmrr
+ another iommu WARN_TAINT, addressed in another patch, have lead to over
a 100 bugs being filed this way.

This commit replaces the WARN_TAINT("...") call, with a
pr_warn(FW_BUG "...") + add_taint(TAINT_FIRMWARE_WORKAROUND, ...) call
avoiding the backtrace and thus also avoiding bug-reports being filed
about this against the kernel.

Fixes: f5a68bb0 ("iommu/vt-d: Mark firmware tainted if RMRR fails sanity check")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Cc: stable@vger.kernel.org
Cc: Barret Rhoden <brho@google.com>
Link: https://lore.kernel.org/r/20200309140138.3753-3-hdegoede@redhat.com
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1808874

There are several places traverse RCU-list without holding any lock in
intel_iommu_init(). Fix them by acquiring dmar_global_lock.

 WARNING: suspicious RCU usage
 -----------------------------
 drivers/iommu/intel-iommu.c:5216 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 no locks held by swapper/0/1.

 Call Trace:
  dump_stack+0xa0/0xea
  lockdep_rcu_suspicious+0x102/0x10b
  intel_iommu_init+0x947/0xb13
  pci_iommu_init+0x26/0x62
  do_one_initcall+0xfe/0x500
  kernel_init_freeable+0x45a/0x4f8
  kernel_init+0x11/0x139
  ret_from_fork+0x3a/0x50
 DMAR: Intel(R) Virtualization Technology for Directed I/O

Fixes: d8190dc6 ("iommu/vt-d: Enable DMA remapping after rmrr mapped")
Signed-off-by: NQian Cai <cai@lca.pw>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a huge
page onto its corresponding physical address. This commit fixes the bug by
accomodating the level of page entry for the IOVA and adds IOVA's lower
address to the physical address.

Cc: <stable@vger.kernel.org>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: NMoritz Fischer <mdf@kernel.org>
Signed-off-by: NYonghyun Hwang <yonghyun@google.com>
Fixes: 38717946 ("VT-d: Changes to support KVM")
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The function only has one call-site and there it is never called with
dummy or deferred devices. Simplify the check in the function to
account for that.

Fixes: 1ee0186b ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable@vger.kernel.org # v5.5
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The function is now only a wrapper around find_domain(). Remove the
function and call find_domain() directly at the call-sites.

Fixes: 1ee0186b ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable@vger.kernel.org # v5.5
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The attachment of deferred devices needs to happen before the check
whether the device is identity mapped or not. Otherwise the check will
return wrong results, cause warnings boot failures in kdump kernels, like

	WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70

	[...]

	 Call Trace:
	  __intel_map_single+0x55/0x190
	  intel_alloc_coherent+0xac/0x110
	  dmam_alloc_attrs+0x50/0xa0
	  ahci_port_start+0xfb/0x1f0 [libahci]
	  ata_host_start.part.39+0x104/0x1e0 [libata]

With the earlier check the kdump boot succeeds and a crashdump is written.

Fixes: 1ee0186b ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable@vger.kernel.org # v5.5
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Move the code that does the deferred device attachment into a separate
helper function.

Fixes: 1ee0186b ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable@vger.kernel.org # v5.5
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Implement a helper function to check whether a device's attach process
is deferred.

Fixes: 1ee0186b ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable@vger.kernel.org # v5.5
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Remove the sanity check required for VMD child devices.  The new
pci_real_dma_dev() DMA alias mechanism places them in the same IOMMU group
as the VMD endpoint.  Assignment of the group would require assigning the
VMD endpoint, where unbinding the VMD endpoint removes the child device
domain from the hierarchy.

Link: https://lore.kernel.org/r/1579613871-301529-6-git-send-email-jonathan.derrick@intel.comSigned-off-by: NJon Derrick <jonathan.derrick@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>

The PCI device may have a DMA requester on another bus, such as VMD
subdevices needing to use the VMD endpoint.  This case requires the real
DMA device for the IOMMU mapping, so use pci_real_dma_dev() to find that
device.

Link: https://lore.kernel.org/r/1579613871-301529-5-git-send-email-jonathan.derrick@intel.comSigned-off-by: NJon Derrick <jonathan.derrick@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>

The iommu default domain framework has been designed to take
care of setting identity default domain type. It's unnecessary
to handle this again in the VT-d driver. Hence, remove it.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Since commit ea2447f7 ("intel-iommu: Prevent devices with
RMRRs from being placed into SI Domain"), the Intel IOMMU driver
doesn't allow any devices with RMRR locked to use the identity
domain. This was added to to fix the issue where the RMRR info
for devices being placed in and out of the identity domain gets
lost. This identity maps all RMRRs when setting up the identity
domain, so that devices with RMRRs could also use it.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The VT-d spec specifies requirements for the RMRR entries base and
end (called 'Limit' in the docs) addresses.

This commit will cause the DMAR processing to mark the firmware as
tainted if any RMRR entries that do not meet these requirements.
Signed-off-by: NBarret Rhoden <brho@google.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

RMRR entries describe memory regions that are DMA targets for devices
outside the kernel's control.

RMRR entries that fail the sanity check are pointing to regions of
memory that the firmware did not tell the kernel are reserved or
otherwise should not be used.

Instead of aborting DMAR processing, this commit marks the firmware
as tainted. These RMRRs will still be identity mapped, otherwise,
some devices, e.x. graphic devices, will not work during boot.
Signed-off-by: NBarret Rhoden <brho@google.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Fixes: f036c7fa ("iommu/vt-d: Check VT-d RMRR region in BIOS is reported as reserved")
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

It is possible for archdata.iommu to be set to
DEFER_DEVICE_DOMAIN_INFO or DUMMY_DEVICE_DOMAIN_INFO so check for
those values before calling __dmar_remove_one_dev_info. Without a
check it can result in a null pointer dereference. This has been seen
while booting a kdump kernel on an HP dl380 gen9.

Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: stable@vger.kernel.org # 5.3+
Cc: linux-kernel@vger.kernel.org
Fixes: ae23bfb6 ("iommu/vt-d: Detach domain before using a private one")
Signed-off-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

If the device fails to be added to the group, make sure to unlink the
reference before returning.
Signed-off-by: NJon Derrick <jonathan.derrick@intel.com>
Fixes: 39ab9555 ("iommu: Add sysfs bindings for struct iommu_device")
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Starting with commit fa212a97 ("iommu/vt-d: Probe DMA-capable ACPI
name space devices"), we now probe DMA-capable ACPI name
space devices. On Dell XPS 13 9343, which has an Intel LPSS platform
device INTL9C60 enumerated via ACPI, this change leads to the following
warning:

    ------------[ cut here ]------------
    WARNING: CPU: 1 PID: 1 at pci_device_group+0x11a/0x130
    CPU: 1 PID: 1 Comm: swapper/0 Tainted: G                T 5.5.0-rc3+ #22
    Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A20 06/06/2019
    RIP: 0010:pci_device_group+0x11a/0x130
    Code: f0 ff ff 48 85 c0 49 89 c4 75 c4 48 8d 74 24 10 48 89 ef e8 48 ef ff ff 48 85 c0 49 89 c4 75 af e8 db f7 ff ff 49 89 c4 eb a5 <0f> 0b 49 c7 c4 ea ff ff ff eb 9a e8 96 1e c7 ff 66 0f 1f 44 00 00
    RSP: 0000:ffffc0d6c0043cb0 EFLAGS: 00010202
    RAX: 0000000000000000 RBX: ffffa3d1d43dd810 RCX: 0000000000000000
    RDX: ffffa3d1d4fecf80 RSI: ffffa3d12943dcc0 RDI: ffffa3d1d43dd810
    RBP: ffffa3d1d43dd810 R08: 0000000000000000 R09: ffffa3d1d4c04a80
    R10: ffffa3d1d4c00880 R11: ffffa3d1d44ba000 R12: 0000000000000000
    R13: ffffa3d1d4383b80 R14: ffffa3d1d4c090d0 R15: ffffa3d1d4324530
    FS:  0000000000000000(0000) GS:ffffa3d1d6700000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000000460a001 CR4: 00000000003606e0
    Call Trace:
     ? iommu_group_get_for_dev+0x81/0x1f0
     ? intel_iommu_add_device+0x61/0x170
     ? iommu_probe_device+0x43/0xd0
     ? intel_iommu_init+0x1fa2/0x2235
     ? pci_iommu_init+0x52/0xe7
     ? e820__memblock_setup+0x15c/0x15c
     ? do_one_initcall+0xcc/0x27e
     ? kernel_init_freeable+0x169/0x259
     ? rest_init+0x95/0x95
     ? kernel_init+0x5/0xeb
     ? ret_from_fork+0x35/0x40
    ---[ end trace 28473e7abc25b92c ]---
    DMAR: ACPI name space devices didn't probe correctly

The bug results from the fact that while we now enumerate ACPI devices,
we aren't able to handle any non-PCI device when generating the device
group. Fix the issue by implementing an Intel-specific callback that
returns `pci_device_group` only if the device is a PCI device.
Otherwise, it will return a generic device group.

Fixes: fa212a97 ("iommu/vt-d: Probe DMA-capable ACPI name space devices")
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Cc: stable@vger.kernel.org # v5.3+
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Export page table internals of the domain attached to each device.
Example of such dump on a Skylake machine:

$ sudo cat /sys/kernel/debug/iommu/intel/domain_translation_struct
[ ... ]
Device 0000:00:14.0 with pasid 0 @0x15f3d9000
IOVA_PFN                PML5E                   PML4E
0x000000008ced0 |       0x0000000000000000      0x000000015f3da003
0x000000008ced1 |       0x0000000000000000      0x000000015f3da003
0x000000008ced2 |       0x0000000000000000      0x000000015f3da003
0x000000008ced3 |       0x0000000000000000      0x000000015f3da003
0x000000008ced4 |       0x0000000000000000      0x000000015f3da003
0x000000008ced5 |       0x0000000000000000      0x000000015f3da003
0x000000008ced6 |       0x0000000000000000      0x000000015f3da003
0x000000008ced7 |       0x0000000000000000      0x000000015f3da003
0x000000008ced8 |       0x0000000000000000      0x000000015f3da003
0x000000008ced9 |       0x0000000000000000      0x000000015f3da003

PDPE                    PDE                     PTE
0x000000015f3db003      0x000000015f3dc003      0x000000008ced0003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced1003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced2003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced3003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced4003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced5003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced6003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced7003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced8003
0x000000015f3db003      0x000000015f3dc003      0x000000008ced9003
[ ... ]
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

After we make all map/unmap paths support first level page table.
Let's turn it on if hardware supports scalable mode.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

First-level translation may map input addresses to 4-KByte pages,
2-MByte pages, or 1-GByte pages. Support for 4-KByte pages and
2-Mbyte pages are mandatory for first-level translation. Hardware
support for 1-GByte page is reported through the FL1GP field in
the Capability Register.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

First-level translation restricts the input-address to a canonical
address (i.e., address bits 63:N have the same value as address
bit [N-1], where N is 48-bits with 4-level paging and 57-bits with
5-level paging). (section 3.6 in the spec)

This makes first level IOVA canonical by using IOVA with bit [N-1]
always cleared.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

When software has changed first-level tables, it should invalidate
the affected IOTLB and the paging-structure-caches using the PASID-
based-IOTLB Invalidate Descriptor defined in spec 6.5.2.4.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Intel VT-d in scalable mode supports two types of page tables for
IOVA translation: first level and second level. The IOMMU driver
can choose one from both for IOVA translation according to the use
case. This sets up the pasid entry if a domain is selected to use
the first-level page table for iova translation.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This adds the Intel VT-d specific callback of setting
DOMAIN_ATTR_NESTING domain attribution. It is necessary
to let the VT-d driver know that the domain represents
a virtual machine which requires the IOMMU hardware to
support nested translation mode. Return success if the
IOMMU hardware suports nested mode, otherwise failure.
Signed-off-by: NYi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This checks whether a domain should use the first level page
table for map/unmap and marks it in the domain structure.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Currently if flush queue initialization fails, we return error
or enforce the system-wide strict mode. These are unnecessary
because we always check the existence of a flush queue before
queuing any iova's for lazy flushing. Printing a informational
message is enough.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

If Intel IOMMU strict mode is enabled by users, it's unnecessary
to create the iova flush queue.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Current map_sg stores trace message in a coarse manner. This
extends it so that more detailed messages could be traced.

The map_sg trace message looks like:

map_sg: dev=0000:00:17.0 [1/9] dev_addr=0xf8f90000 phys_addr=0x158051000 size=4096
map_sg: dev=0000:00:17.0 [2/9] dev_addr=0xf8f91000 phys_addr=0x15a858000 size=4096
map_sg: dev=0000:00:17.0 [3/9] dev_addr=0xf8f92000 phys_addr=0x15aa13000 size=4096
map_sg: dev=0000:00:17.0 [4/9] dev_addr=0xf8f93000 phys_addr=0x1570f1000 size=8192
map_sg: dev=0000:00:17.0 [5/9] dev_addr=0xf8f95000 phys_addr=0x15c6d0000 size=4096
map_sg: dev=0000:00:17.0 [6/9] dev_addr=0xf8f96000 phys_addr=0x157194000 size=4096
map_sg: dev=0000:00:17.0 [7/9] dev_addr=0xf8f97000 phys_addr=0x169552000 size=4096
map_sg: dev=0000:00:17.0 [8/9] dev_addr=0xf8f98000 phys_addr=0x169dde000 size=4096
map_sg: dev=0000:00:17.0 [9/9] dev_addr=0xf8f99000 phys_addr=0x148351000 size=4096
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Make use of generic IOASID code to manage PASID allocation,
free, and lookup. Replace Intel specific code.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Shared Virtual Memory(SVM) is based on a collective set of hardware
features detected at runtime. There are requirements for matching CPU
and IOMMU capabilities.

The current code checks CPU and IOMMU feature set for SVM support but
the result is never stored nor used. Therefore, SVM can still be used
even when these checks failed. The consequences can be:
1. CPU uses 5-level paging mode for virtual address of 57 bits, but
IOMMU can only support 4-level paging mode with 48 bits address for DMA.
2. 1GB page size is used by CPU but IOMMU does not support it. VT-d
unrecoverable faults may be generated.

The best solution to fix these problems is to prevent them in the first
place.

This patch consolidates code for checking PASID, CPU vs. IOMMU paging
mode compatibility, as well as provides specific error messages for
each failed checks. On sane hardware configurations, these error message
shall never appear in kernel log.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This adds Kconfig option INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON
to make it easier for distributions to enable or disable the
Intel IOMMU scalable mode by default during kernel build.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Use the new standard function instead of open-coding it.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

When running heavy memory pressure workloads, this 5+ old system is
throwing endless warnings below because disk IO is too slow to recover
from swapping. Since the volume from alloc_iova_fast() could be large,
once it calls printk(), it will trigger disk IO (writing to the log
files) and pending softirqs which could cause an infinite loop and make
no progress for days by the ongoimng memory reclaim. This is the counter
part for Intel where the AMD part has already been merged. See the
commit 3d708895 ("iommu/amd: Silence warnings under memory
pressure"). Since the allocation failure will be reported in
intel_alloc_iova(), so just call dev_err_once() there because even the
"ratelimited" is too much, and silence the one in alloc_iova_mem() to
avoid the expensive warn_alloc().

 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 slab_out_of_memory: 66 callbacks suppressed
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
   cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
   node 0: slabs: 1822, objs: 16398, free: 0
   node 1: slabs: 2051, objs: 18459, free: 31
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
   cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
   node 0: slabs: 1822, objs: 16398, free: 0
   node 1: slabs: 2051, objs: 18459, free: 31
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
   cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   node 0: slabs: 697, objs: 4182, free: 0
   node 0: slabs: 697, objs: 4182, free: 0
   node 0: slabs: 697, objs: 4182, free: 0
   node 0: slabs: 697, objs: 4182, free: 0
   node 1: slabs: 381, objs: 2286, free: 27
   node 1: slabs: 381, objs: 2286, free: 27
   node 1: slabs: 381, objs: 2286, free: 27
   node 1: slabs: 381, objs: 2286, free: 27
   node 0: slabs: 1822, objs: 16398, free: 0
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   node 1: slabs: 2051, objs: 18459, free: 31
   node 0: slabs: 697, objs: 4182, free: 0
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
   node 1: slabs: 381, objs: 2286, free: 27
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   node 0: slabs: 697, objs: 4182, free: 0
   node 1: slabs: 381, objs: 2286, free: 27
 hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
 warn_alloc: 96 callbacks suppressed
 kworker/11:1H: page allocation failure: order:0,
mode:0xa20(GFP_ATOMIC), nodemask=(null),cpuset=/,mems_allowed=0-1
 CPU: 11 PID: 1642 Comm: kworker/11:1H Tainted: G    B
 Hardware name: HP ProLiant XL420 Gen9/ProLiant XL420 Gen9, BIOS U19
12/27/2015
 Workqueue: kblockd blk_mq_run_work_fn
 Call Trace:
  dump_stack+0xa0/0xea
  warn_alloc.cold.94+0x8a/0x12d
  __alloc_pages_slowpath+0x1750/0x1870
  __alloc_pages_nodemask+0x58a/0x710
  alloc_pages_current+0x9c/0x110
  alloc_slab_page+0xc9/0x760
  allocate_slab+0x48f/0x5d0
  new_slab+0x46/0x70
  ___slab_alloc+0x4ab/0x7b0
  __slab_alloc+0x43/0x70
  kmem_cache_alloc+0x2dd/0x450
 SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
  alloc_iova+0x33/0x210
   cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
   node 0: slabs: 697, objs: 4182, free: 0
  alloc_iova_fast+0x62/0x3d1
   node 1: slabs: 381, objs: 2286, free: 27
  intel_alloc_iova+0xce/0xe0
  intel_map_sg+0xed/0x410
  scsi_dma_map+0xd7/0x160
  scsi_queue_rq+0xbf7/0x1310
  blk_mq_dispatch_rq_list+0x4d9/0xbc0
  blk_mq_sched_dispatch_requests+0x24a/0x300
  __blk_mq_run_hw_queue+0x156/0x230
  blk_mq_run_work_fn+0x3b/0x40
  process_one_work+0x579/0xb90
  worker_thread+0x63/0x5b0
  kthread+0x1e6/0x210
  ret_from_fork+0x3a/0x50
 Mem-Info:
 active_anon:2422723 inactive_anon:361971 isolated_anon:34403
  active_file:2285 inactive_file:1838 isolated_file:0
  unevictable:0 dirty:1 writeback:5 unstable:0
  slab_reclaimable:13972 slab_unreclaimable:453879
  mapped:2380 shmem:154 pagetables:6948 bounce:0
  free:19133 free_pcp:7363 free_cma:0
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Currently the reserved region for ISA is allocated with no
permissions. If a dma domain is being used, mapping this region will
fail. Set the permissions to DMA_PTE_READ|DMA_PTE_WRITE.

Cc: Joerg Roedel <jroedel@suse.de>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: stable@vger.kernel.org # v5.3+
Fixes: d850c2ee ("iommu/vt-d: Expose ISA direct mapping region via iommu_get_resv_regions")
Signed-off-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

If the default DMA domain of a group doesn't fit a device, it
will still sit in the group but use a private identity domain.
When map/unmap/iova_to_phys come through iommu API, the driver
should still serve them, otherwise, other devices in the same
group will be impacted. Since identity domain has been mapped
with the whole available memory space and RMRRs, we don't need
to worry about the impact on it.

Link: https://www.spinics.net/lists/iommu/msg40416.html
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Reported-by: NJerry Snitselaar <jsnitsel@redhat.com>
Fixes: 942067f1 ("iommu/vt-d: Identify default domains replaced with private")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Tested-by: NJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Commit d850c2ee ("iommu/vt-d: Expose ISA direct mapping region via
iommu_get_resv_regions") created a direct-mapped reserved memory region
in order to replace the static identity mapping of the ISA address
space, where the latter was then removed in commit df4f3c60
("iommu/vt-d: Remove static identity map code").  According to the
history of this code and the Kconfig option surrounding it, this direct
mapping exists for the benefit of legacy ISA drivers that are not
compatible with the DMA API.

In conjuntion with commit 9b77e5c7 ("vfio/type1: check dma map
request is within a valid iova range") this change introduced a
regression where the vfio IOMMU backend enforces reserved memory regions
per IOMMU group, preventing userspace from creating IOMMU mappings
conflicting with prescribed reserved regions.  A necessary prerequisite
for the vfio change was the introduction of "relaxable" direct mappings
introduced by commit adfd3738 ("iommu: Introduce
IOMMU_RESV_DIRECT_RELAXABLE reserved memory regions").  These relaxable
direct mappings provide the same identity mapping support in the default
domain, but also indicate that the reservation is software imposed and
may be relaxed under some conditions, such as device assignment.

Convert the ISA bridge direct-mapped reserved region to relaxable to
reflect that the restriction is self imposed and need not be enforced
by drivers such as vfio.

Fixes: 1c5c59fb ("iommu/vt-d: Differentiate relaxable and non relaxable RMRRs")
Cc: stable@vger.kernel.org # v5.3+
Link: https://lore.kernel.org/linux-iommu/20191211082304.2d4fab45@x1.homeReported-by: Ncprt <cprt@protonmail.com>
Tested-by: Ncprt <cprt@protonmail.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Tested-by: NJerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>