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Filename Latest commit message Latest commit date
Saeed Mirzamohammadi 456fd88922 iommu/vt-d: Fix agaw for a supported 48 bit guest address width
[ Upstream commit 327d5b2fee91c404a3956c324193892cf2cc9528 ]

The IOMMU driver calculates the guest addressability for a DMA request
based on the value of the mgaw reported from the IOMMU. However, this
is a fused value and as mentioned in the spec, the guest width
should be calculated based on the minimum of supported adjusted guest
address width (SAGAW) and MGAW.

This is from specification:
"Guest addressability for a given DMA request is limited to the
minimum of the value reported through this field and the adjusted
guest address width of the corresponding page-table structure.
(Adjusted guest address widths supported by hardware are reported
through the SAGAW field)."

This causes domain initialization to fail and following
errors appear for EHCI PCI driver:

[    2.486393] ehci-pci 0000:01:00.4: EHCI Host Controller
[    2.486624] ehci-pci 0000:01:00.4: new USB bus registered, assigned bus
number 1
[    2.489127] ehci-pci 0000:01:00.4: DMAR: Allocating domain failed
[    2.489350] ehci-pci 0000:01:00.4: DMAR: 32bit DMA uses non-identity
mapping
[    2.489359] ehci-pci 0000:01:00.4: can't setup: -12
[    2.489531] ehci-pci 0000:01:00.4: USB bus 1 deregistered
[    2.490023] ehci-pci 0000:01:00.4: init 0000:01:00.4 fail, -12
[    2.490358] ehci-pci: probe of 0000:01:00.4 failed with error -12

This issue happens when the value of the sagaw corresponds to a
48-bit agaw. This fix updates the calculation of the agaw based on
the minimum of IOMMU's sagaw value and MGAW.

This issue happens on the code path of getting a private domain for a
device. A private domain was needed when the domain of an iommu group
couldn't meet the requirement of a device. The IOMMU core has been
evolved to eliminate the need for private domain, hence this code path
has alreay been removed from the upstream since commit 327d5b2fee91c
("iommu/vt-d: Allow 32bit devices to uses DMA domain"). Instead of back
porting all patches that are required for removing the private domain,
this simply fixes it in the affected stable kernel between v4.16 and v5.7.

[baolu: The orignal patch could be found here
 https://lore.kernel.org/linux-iommu/20210412202736.70765-1-saeed.mirzamohammadi@oracle.com/.
 I added commit message according to Greg's comments at
 https://lore.kernel.org/linux-iommu/YHZ%2FT9x7Xjf1r6fI@kroah.com/.]

Cc: Joerg Roedel <joro@8bytes.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org #v4.16+
Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Tested-by: Camille Lu <camille.lu@hpe.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18 08:57:04 +02:00
arch KVM: VMX: Use current VMCS to query WAITPKG support for MSR emulation 2021-08-18 08:57:03 +02:00
block blk-iolatency: error out if blk_get_queue() failed in iolatency_set_limit() 2021-08-12 13:20:58 +02:00
certs certs: Move load_system_certificate_list to a common function 2021-06-30 08:47:55 -04:00
crypto crypto: shash - avoid comparing pointers to exported functions under CFI 2021-07-14 16:53:13 +02:00
Documentation KVM: X86: MMU: Use the correct inherited permissions to get shadow page 2021-08-15 13:08:04 +02:00
drivers iommu/vt-d: Fix agaw for a supported 48 bit guest address width 2021-08-18 08:57:04 +02:00
fs ceph: take snap_empty_lock atomically with snaprealm refcount change 2021-08-18 08:57:04 +02:00
include vmlinux.lds.h: Handle clang's module.{c,d}tor sections 2021-08-18 08:57:04 +02:00
init kbuild: add CONFIG_LD_IS_LLD 2021-06-30 08:47:44 -04:00
ipc
kernel genirq/timings: Prevent potential array overflow in __irq_timings_store() 2021-08-18 08:57:02 +02:00
lib lib/decompress_unlz4.c: correctly handle zero-padding around initrds. 2021-07-20 16:10:46 +02:00
LICENSES
mm mm: slab: fix kmem_cache_create failed when sysfs node not destroyed 2021-07-25 14:35:14 +02:00
net vsock/virtio: avoid potential deadlock when vsock device remove 2021-08-18 08:57:01 +02:00
samples samples/bpf: Fix the error return code of xdp_redirect's main() 2021-07-14 16:53:30 +02:00
scripts scripts/tracing: fix the bug that can't parse raw_trace_func 2021-08-12 13:21:00 +02:00
security smackfs: restrict bytes count in smk_set_cipso() 2021-07-19 08:53:18 +02:00
sound ASoC: cs42l42: Fix LRCLK frame start edge 2021-08-18 08:56:58 +02:00
tools bpf, selftests: Adjust few selftest result_unpriv outcomes 2021-08-12 13:21:04 +02:00
usr
virt KVM: Do not leak memory for duplicate debugfs directories 2021-08-12 13:21:03 +02:00
.clang-format
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.gitignore
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COPYING
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Makefile Linux 5.4.141 2021-08-15 13:08:06 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.