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[ Upstream commit cb30dfa75d55eced379a42fd67bd5fb7ec38555e ]
If pgshift is 63 then BITS_PER_TYPE(*bitmap->bitmap) * pgsize will overflow
to 0 and this triggers divide by 0.
In this case the index should just be 0, so reorganize things to divide
by shift and avoid hitting any overflows.
Link: https://patch.msgid.link/r/0-v1-663679b57226+172-iommufd_dirty_div0_jgg@nvidia.com
Cc: stable@vger.kernel.org
Fixes: 58ccf0190d19 ("vfio: Add an IOVA bitmap support")
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: syzbot+093a8a8b859472e6c257@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=093a8a8b859472e6c257
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[ drivers/iommu/iommufd/iova_bitmap.c => drivers/vfio/iova_bitmap.c ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 16df67f2189a71a8310bcebddb87ed569e8352be ]
The two implementers of vfio_device_ops.device_feature,
vfio_cdx_ioctl_feature and vfio_pci_core_ioctl_feature, return
-ENOTTY in the fallthrough case when the feature is unsupported. For
consistency, the base case, vfio_ioctl_device_feature, should do the
same when device_feature == NULL, indicating an implementation has no
feature extensions.
Signed-off-by: Alex Mastro <amastro@fb.com>
Link: https://lore.kernel.org/r/20250908-vfio-enotty-v1-1-4428e1539e2e@fb.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit acb59a4bb8ed34e738a4c3463127bf3f6b5e11a9 ]
host_seq_bmp is allocated with vzalloc but is currently freed with
bitmap_free, which uses kfree internally. This mismach prevents the
resource from being released properly and may result in memory leaks
or other issues.
Fix this by freeing host_seq_bmp with vfree to match the vzalloc
allocation.
Fixes: f232836a9152 ("vfio/pds: Add support for dirty page tracking")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20250913153154.1028835-1-zilin@seu.edu.cn
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b3060198483bac43ec113c62ae3837076f61f5de ]
MLX cap pg_track_log_max_msg_size consists of 5 bits, value of which is
used as power of 2 for max_msg_size. This can lead to multiplication
overflow between max_msg_size (u32) and integer constant, and afterwards
incorrect value is being written to rq_size.
Fix this issue by extending integer constant to u64 type.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20250701144017.2410-2-a.sadovnikov@ispras.ru
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b1779e4f209c7ff7e32f3c79d69bca4e3a3a68b6 ]
A large DMA mapping request can loop through dma address pinning for
many pages. In cases where THP can not be used, the repeated vmf_insert_pfn can
be costly, so let the task reschedule as need to prevent CPU stalls. Failure to
do so has potential harmful side effects, like increased memory pressure
as unrelated rcu tasks are unable to make their reclaim callbacks and
result in OOM conditions.
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 36-....: (20999 ticks this GP) idle=b01c/1/0x4000000000000000 softirq=35839/35839 fqs=3538
rcu: hardirqs softirqs csw/system
rcu: number: 0 107 0
rcu: cputime: 50 0 10446 ==> 10556(ms)
rcu: (t=21075 jiffies g=377761 q=204059 ncpus=384)
...
<TASK>
? asm_sysvec_apic_timer_interrupt+0x16/0x20
? walk_system_ram_range+0x63/0x120
? walk_system_ram_range+0x46/0x120
? pgprot_writethrough+0x20/0x20
lookup_memtype+0x67/0xf0
track_pfn_insert+0x20/0x40
vmf_insert_pfn_prot+0x88/0x140
vfio_pci_mmap_huge_fault+0xf9/0x1b0 [vfio_pci_core]
__do_fault+0x28/0x1b0
handle_mm_fault+0xef1/0x2560
fixup_user_fault+0xf5/0x270
vaddr_get_pfns+0x169/0x2f0 [vfio_iommu_type1]
vfio_pin_pages_remote+0x162/0x8e0 [vfio_iommu_type1]
vfio_iommu_type1_ioctl+0x1121/0x1810 [vfio_iommu_type1]
? futex_wake+0x1c1/0x260
x64_sys_call+0x234/0x17a0
do_syscall_64+0x63/0x130
? exc_page_fault+0x63/0x130
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20250715184622.3561598-1-kbusch@meta.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e908f58b6beb337cbe4481d52c3f5c78167b1aab ]
In the below noted Fixes commit we introduced a reflck mutex to allow
better scaling between devices for open and close. The reflck was
based on the hot reset granularity, device level for root bus devices
which cannot support hot reset or bus/slot reset otherwise. Overlooked
in this were SR-IOV VFs, where there's also no bus reset option, but
the default for a non-root-bus, non-slot-based device is bus level
reflck granularity.
The reflck mutex has since become the dev_set mutex (via commit
2cd8b14aaa66 ("vfio/pci: Move to the device set infrastructure")) and
is our defacto serialization for various operations and ioctls. It
still seems to be the case though that sets of vfio-pci devices really
only need serialization relative to hot resets affecting the entire
set, which is not relevant to SR-IOV VFs. As described in the Closes
link below, this serialization contributes to startup latency when
multiple VFs sharing the same "bus" are opened concurrently.
Mark the device itself as the basis of the dev_set for SR-IOV VFs.
Reported-by: Aaron Lewis <aaronlewis@google.com>
Closes: https://lore.kernel.org/all/20250626180424.632628-1-aaronlewis@google.com
Tested-by: Aaron Lewis <aaronlewis@google.com>
Fixes: e309df5b0c9e ("vfio/pci: Parallelize device open and release")
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250626225623.1180952-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit fe24d5bc635e103a517ec201c3cb571eeab8be2f ]
When CONFIG_IOMMUFD is enabled and a device is bound to the pds_vfio_pci
driver, the following WARN_ON() trace is seen and probe fails:
WARNING: CPU: 0 PID: 5040 at drivers/vfio/vfio_main.c:317 __vfio_register_dev+0x130/0x140 [vfio]
<...>
pds_vfio_pci 0000:08:00.1: probe with driver pds_vfio_pci failed with error -22
This is because the driver's vfio_device_ops.detach_ioas isn't set.
Fix this by using the generic vfio_iommufd_physical_detach_ioas
function.
Fixes: 38fe3975b4c2 ("vfio/pds: Initial support for pds VFIO driver")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250702163744.69767-1-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 982ddd59ed97dc7e63efd97ed50273ffb817bd41 ]
When vfio_df_close() is called with open_count=0, it triggers a warning in
vfio_assert_device_open() but still decrements open_count to -1. This allows
a subsequent open to incorrectly pass the open_count == 0 check, leading to
unintended behavior, such as setting df->access_granted = true.
For example, running an IOMMUFD compat no-IOMMU device with VFIO tests
(https://github.com/awilliam/tests/blob/master/vfio-noiommu-pci-device-open.c)
results in a warning and a failed VFIO_GROUP_GET_DEVICE_FD ioctl on the first
run, but the second run succeeds incorrectly.
Add checks to avoid decrementing open_count below zero.
Fixes: 05f37e1c03b6 ("vfio: Pass struct vfio_device_file * to vfio_device_open/close()")
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250618234618.1910456-2-jacob.pan@linux.microsoft.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b25e271b377999191b12f0afbe1861edcf57e3fe ]
For devices with no-iommu enabled in IOMMUFD VFIO compat mode, the group open
path skips vfio_df_open(), leaving open_count at 0. This causes a warning in
vfio_assert_device_open(device) when vfio_df_close() is called during group
close.
The correct behavior is to skip only the IOMMUFD bind in the device open path
for no-iommu devices. Commit 6086efe73498 omitted vfio_df_open(), which was
too broad. This patch restores the previous behavior, ensuring
the vfio_df_open is called in the group open path.
Fixes: 6086efe73498 ("vfio-iommufd: Move noiommu compat validation out of vfio_iommufd_bind()")
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250618234618.1910456-1-jacob.pan@linux.microsoft.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4518e5a60c7fbf0cdff393c2681db39d77b4f87e ]
When setting up dirty page tracking at the vfio IOMMU backend for
device migration, if an error is encountered allocating a tracking
bitmap, the unwind loop fails to free previously allocated tracking
bitmaps. This occurs because the wrong loop index is used to
generate the tracking object. This results in unintended memory
usage for the life of the current DMA mappings where bitmaps were
successfully allocated.
Use the correct loop index to derive the tracking object for
freeing during unwind.
Fixes: d6a4c185660c ("vfio iommu: Implementation of ioctl for dirty pages tracking")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://lore.kernel.org/r/20250521034647.2877-1-lirongqing@baidu.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2777a40998deb36f96b6afc48bd397cf58a4edf0 ]
If the VF device driver is not loaded in the Guest OS and we attempt to
perform device data migration, the address of the migrated data will
be NULL.
The live migration recovery operation on the destination side will
access a null address value, which will cause access errors.
Therefore, live migration of VMs without added VF device drivers
does not require device data migration.
In addition, when the queue address data obtained by the destination
is empty, device queue recovery processing will not be performed.
Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250510081155.55840-6-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3495cec0787721ba7a9d5c19d0bbb66d182de584 ]
In order to ensure that the task packets of the accelerator
device are not lost during the migration process, it is necessary
to send an EQ and AEQ command to the device after the live migration
is completed and to update the completion position of the task queue.
Let the device recheck the completed tasks data and if there are
uncollected packets, device resend a task completion interrupt
to the software.
Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250510081155.55840-3-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8bb7170c5a055ea17c6857c256ee73c10ff872eb ]
The dma addresses of EQE and AEQE are wrong after migration and
results in guest kernel-mode encryption services failure.
Comparing the definition of hardware registers, we found that
there was an error when the data read from the register was
combined into an address. Therefore, the address combination
sequence needs to be corrected.
Even after fixing the above problem, we still have an issue
where the Guest from an old kernel can get migrated to
new kernel and may result in wrong data.
In order to ensure that the address is correct after migration,
if an old magic number is detected, the dma address needs to be
updated.
Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250510081155.55840-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 860be250fc32de9cb24154bf21b4e36f40925707 ]
Some systems report INTx as not routed by setting pdev->irq to
IRQ_NOTCONNECTED, resulting in a -ENOTCONN error when trying to
setup eventfd signaling. Include this in the set of conditions
for which the PIN register is virtualized to zero.
Additionally consolidate vfio_pci_get_irq_count() to use this
virtualized value in reporting INTx support via ioctl and sanity
checking ioctl paths since pdev->irq is re-used when the device
is in MSI mode.
The combination of these results in both the config space of the
device and the ioctl interface behaving as if the device does not
support INTx.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250311230623.1264283-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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This reverts commit 03844b1908114680ca35fa0a0aba3d906a6d78af.
It had been committed multiple times to the tree, and isn't needed
again.
Link: https://lore.kernel.org/r/a082db2605514513a0a8568382d5bd2b6f1877a0.camel@cyberus-technology.de
Reported-by: Stefan Nürnberger <stefan.nuernberger@cyberus-technology.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2b938e3db335e3670475e31a722c2bee34748c5a ]
Definitions of ioread64 and iowrite64 macros in asm/io.h called by vfio
pci implementations are enclosed inside check for CONFIG_GENERIC_IOMAP.
They don't get defined if CONFIG_GENERIC_IOMAP is defined. Include
linux/io-64-nonatomic-lo-hi.h to define iowrite64 and ioread64 macros
when they are not defined. io-64-nonatomic-lo-hi.h maps the macros to
generic implementation in lib/iomap.c. The generic implementation does
64 bit rw if readq/writeq is defined for the architecture, otherwise it
would do 32 bit back to back rw.
Note that there are two versions of the generic implementation that
differs in the order the 32 bit words are written if 64 bit support is
not present. This is not the little/big endian ordering, which is
handled separately. This patch uses the lo followed by hi word ordering
which is consistent with current back to back implementation in the
vfio/pci code.
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241210131938.303500-2-ramesh.thomas@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit ce9ff21ea89d191e477a02ad7eabf4f996b80a69 upstream.
count and offset are passed from user space and not checked, only
offset is capped to 40 bits, which can be used to read/write out of
bounds of the device.
Fixes: 6e3f26456009 (“vfio/platform: read and write support for the device fd”)
Cc: stable@vger.kernel.org
Reported-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e24c1551059268b37f6f40639883eafb281b8b9c ]
Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index()
where shifting the constant "1" (of type int) by bitmap->mapped.pgshift
(an unsigned long value) could result in undefined behavior.
The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds
31 (e.g., pgshift = 63) the shift operation overflows, as the result
cannot be represented in a 32-bit type.
To resolve this, the constant is updated to "1UL", promoting it to an
unsigned long type to match the operand's type.
Fixes: 58ccf0190d19 ("vfio: Add an IOVA bitmap support")
Link: https://patch.msgid.link/r/20250113223820.10713-1-qasdev00@gmail.com
Reported-by: syzbot <syzbot+85992ace37d5b7b51635@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=85992ace37d5b7b51635
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit ce9ff21ea89d191e477a02ad7eabf4f996b80a69 upstream.
count and offset are passed from user space and not checked, only
offset is capped to 40 bits, which can be used to read/write out of
bounds of the device.
Fixes: 6e3f26456009 (“vfio/platform: read and write support for the device fd”)
Cc: stable@vger.kernel.org
Reported-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 9c7c5430bca36e9636eabbba0b3b53251479c7ab ]
Align the page tracking maximum message size with the device's
capability instead of relying on PAGE_SIZE.
This adjustment resolves a mismatch on systems where PAGE_SIZE is 64K,
but the firmware only supports a maximum message size of 4K.
Now that we rely on the device's capability for max_message_size, we
must account for potential future increases in its value.
Key considerations include:
- Supporting message sizes that exceed a single system page (e.g., an 8K
message on a 4K system).
- Ensuring the RQ size is adjusted to accommodate at least 4
WQEs/messages, in line with the device specification.
The above has been addressed as part of the patch.
Fixes: 79c3cf279926 ("vfio/mlx5: Init QP based resources for dirty tracking")
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: Yingshun Cui <yicui@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20241205122654.235619-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit fe4bf8d0b6716a423b16495d55b35d3fe515905d ]
There are cases where a PCIe extended capability should be hidden from
the user. For example, an unknown capability (i.e., capability with ID
greater than PCI_EXT_CAP_ID_MAX) or a capability that is intentionally
chosen to be hidden from the user.
Hiding a capability is done by virtualizing and modifying the 'Next
Capability Offset' field of the previous capability so it points to the
capability after the one that should be hidden.
The special case where the first capability in the list should be hidden
is handled differently because there is no previous capability that can
be modified. In this case, the capability ID and version are zeroed
while leaving the next pointer intact. This hides the capability and
leaves an anchor for the rest of the capability list.
However, today, hiding the first capability in the list is not done
properly if the capability is unknown, as struct
vfio_pci_core_device->pci_config_map is set to the capability ID during
initialization but the capability ID is not properly checked later when
used in vfio_config_do_rw(). This leads to the following warning [1] and
to an out-of-bounds access to ecap_perms array.
Fix it by checking cap_id in vfio_config_do_rw(), and if it is greater
than PCI_EXT_CAP_ID_MAX, use an alternative struct perm_bits for direct
read only access instead of the ecap_perms array.
Note that this is safe since the above is the only case where cap_id can
exceed PCI_EXT_CAP_ID_MAX (except for the special capabilities, which
are already checked before).
[1]
WARNING: CPU: 118 PID: 5329 at drivers/vfio/pci/vfio_pci_config.c:1900 vfio_pci_config_rw+0x395/0x430 [vfio_pci_core]
CPU: 118 UID: 0 PID: 5329 Comm: simx-qemu-syste Not tainted 6.12.0+ #1
(snip)
Call Trace:
<TASK>
? show_regs+0x69/0x80
? __warn+0x8d/0x140
? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core]
? report_bug+0x18f/0x1a0
? handle_bug+0x63/0xa0
? exc_invalid_op+0x19/0x70
? asm_exc_invalid_op+0x1b/0x20
? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core]
? vfio_pci_config_rw+0x244/0x430 [vfio_pci_core]
vfio_pci_rw+0x101/0x1b0 [vfio_pci_core]
vfio_pci_core_read+0x1d/0x30 [vfio_pci_core]
vfio_device_fops_read+0x27/0x40 [vfio]
vfs_read+0xbd/0x340
? vfio_device_fops_unl_ioctl+0xbb/0x740 [vfio]
? __rseq_handle_notify_resume+0xa4/0x4b0
__x64_sys_pread64+0x96/0xc0
x64_sys_call+0x1c3d/0x20d0
do_syscall_64+0x4d/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20241124142739.21698-1-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 4ba2fdff2eb174114786784926d0efb6903c88a6 ]
The PAPR expects the TCE table to have no entries at the time of
unset window(i.e. remove-pe). The TCE clear right now is done
before freeing the iommu table. On pSeries, the unset window
makes those entries inaccessible to the OS and the H_PUT/GET calls
fail on them with H_CONSTRAINED.
On PowerNV, this has no side effect as the TCE clear can be done
before the DMA window removal as well.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/171923273535.1397.1236742071894414895.stgit@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 5a88a3f67e37e39f933b38ebb4985ba5822e9eca ]
The count variable is used without initialization, it results in mistakes
in the device counting and crashes the userspace if the get hot reset info
path is triggered.
Fixes: f6944d4a0b87 ("vfio/pci: Collect hot-reset devices to local buffer")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219010
Reported-by: Žilvinas Žaltiena <zaltys@natrix.lt>
Cc: Beld Zhang <beldzhang@gmail.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240710004150.319105-1-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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[ Upstream commit f6944d4a0b87c16bc34ae589169e1ded3d4db08e ]
Lockdep reports the below circular locking dependency issue. The
mmap_lock acquisition while holding pci_bus_sem is due to the use of
copy_to_user() from within a pci_walk_bus() callback.
Building the devices array directly into the user buffer is only for
convenience. Instead we can allocate a local buffer for the array,
bounded by the number of devices on the bus/slot, fill the device
information into this local buffer, then copy it into the user buffer
outside the bus walk callback.
======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc5+ #39 Not tainted
------------------------------------------------------
CPU 0/KVM/4113 is trying to acquire lock:
ffff99a609ee18a8 (&vdev->vma_lock){+.+.}-{4:4}, at: vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
but task is already holding lock:
ffff99a243a052a0 (&mm->mmap_lock){++++}-{4:4}, at: vaddr_get_pfns+0x3f/0x170 [vfio_iommu_type1]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&mm->mmap_lock){++++}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
__might_fault+0x5c/0x80
_copy_to_user+0x1e/0x60
vfio_pci_fill_devs+0x9f/0x130 [vfio_pci_core]
vfio_pci_walk_wrapper+0x45/0x60 [vfio_pci_core]
__pci_walk_bus+0x6b/0xb0
vfio_pci_ioctl_get_pci_hot_reset_info+0x10b/0x1d0 [vfio_pci_core]
vfio_pci_core_ioctl+0x1cb/0x400 [vfio_pci_core]
vfio_device_fops_unl_ioctl+0x7e/0x140 [vfio]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #2 (pci_bus_sem){++++}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
down_read+0x3e/0x160
pci_bridge_wait_for_secondary_bus.part.0+0x33/0x2d0
pci_reset_bus+0xdd/0x160
vfio_pci_dev_set_hot_reset+0x256/0x270 [vfio_pci_core]
vfio_pci_ioctl_pci_hot_reset_groups+0x1a3/0x280 [vfio_pci_core]
vfio_pci_core_ioctl+0x3b5/0x400 [vfio_pci_core]
vfio_device_fops_unl_ioctl+0x7e/0x140 [vfio]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&vdev->memory_lock){+.+.}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
down_write+0x3b/0xc0
vfio_pci_zap_and_down_write_memory_lock+0x1c/0x30 [vfio_pci_core]
vfio_basic_config_write+0x281/0x340 [vfio_pci_core]
vfio_config_do_rw+0x1fa/0x300 [vfio_pci_core]
vfio_pci_config_rw+0x75/0xe50 [vfio_pci_core]
vfio_pci_rw+0xea/0x1a0 [vfio_pci_core]
vfs_write+0xea/0x520
__x64_sys_pwrite64+0x90/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&vdev->vma_lock){+.+.}-{4:4}:
check_prev_add+0xeb/0xcc0
validate_chain+0x465/0x530
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
__mutex_lock+0x97/0xde0
vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
__do_fault+0x31/0x160
do_pte_missing+0x65/0x3b0
__handle_mm_fault+0x303/0x720
handle_mm_fault+0x10f/0x460
fixup_user_fault+0x7f/0x1f0
follow_fault_pfn+0x66/0x1c0 [vfio_iommu_type1]
vaddr_get_pfns+0xf2/0x170 [vfio_iommu_type1]
vfio_pin_pages_remote+0x348/0x4e0 [vfio_iommu_type1]
vfio_pin_map_dma+0xd2/0x330 [vfio_iommu_type1]
vfio_dma_do_map+0x2c0/0x440 [vfio_iommu_type1]
vfio_iommu_type1_ioctl+0xc5/0x1d0 [vfio_iommu_type1]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of:
&vdev->vma_lock --> pci_bus_sem --> &mm->mmap_lock
Possible unsafe locking scenario:
block dm-0: the capability attribute has been deprecated.
CPU0 CPU1
---- ----
rlock(&mm->mmap_lock);
lock(pci_bus_sem);
lock(&mm->mmap_lock);
lock(&vdev->vma_lock);
*** DEADLOCK ***
2 locks held by CPU 0/KVM/4113:
#0: ffff99a25f294888 (&iommu->lock#2){+.+.}-{4:4}, at: vfio_dma_do_map+0x60/0x440 [vfio_iommu_type1]
#1: ffff99a243a052a0 (&mm->mmap_lock){++++}-{4:4}, at: vaddr_get_pfns+0x3f/0x170 [vfio_iommu_type1]
stack backtrace:
CPU: 1 PID: 4113 Comm: CPU 0/KVM Not tainted 6.9.0-rc5+ #39
Hardware name: Dell Inc. PowerEdge T640/04WYPY, BIOS 2.15.1 06/16/2022
Call Trace:
<TASK>
dump_stack_lvl+0x64/0xa0
check_noncircular+0x131/0x150
check_prev_add+0xeb/0xcc0
? add_chain_cache+0x10a/0x2f0
? __lock_acquire+0x4e4/0xb90
validate_chain+0x465/0x530
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? lock_is_held_type+0x9a/0x110
__mutex_lock+0x97/0xde0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? lock_acquire+0xbc/0x2d0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? find_held_lock+0x2b/0x80
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
__do_fault+0x31/0x160
do_pte_missing+0x65/0x3b0
__handle_mm_fault+0x303/0x720
handle_mm_fault+0x10f/0x460
fixup_user_fault+0x7f/0x1f0
follow_fault_pfn+0x66/0x1c0 [vfio_iommu_type1]
vaddr_get_pfns+0xf2/0x170 [vfio_iommu_type1]
vfio_pin_pages_remote+0x348/0x4e0 [vfio_iommu_type1]
vfio_pin_map_dma+0xd2/0x330 [vfio_iommu_type1]
vfio_dma_do_map+0x2c0/0x440 [vfio_iommu_type1]
vfio_iommu_type1_ioctl+0xc5/0x1d0 [vfio_iommu_type1]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
? rcu_core+0x8d/0x250
? __lock_release+0x5e/0x160
? rcu_core+0x8d/0x250
? lock_release+0x5f/0x120
? sched_clock+0xc/0x30
? sched_clock_cpu+0xb/0x190
? irqtime_account_irq+0x40/0xc0
? __local_bh_enable+0x54/0x60
? __do_softirq+0x315/0x3ca
? lockdep_hardirqs_on_prepare.part.0+0x97/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f8300d0357b
Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 68 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007f82ef3fb948 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8300d0357b
RDX: 00007f82ef3fb990 RSI: 0000000000003b71 RDI: 0000000000000023
RBP: 00007f82ef3fb9c0 R08: 0000000000000000 R09: 0000561b7e0bcac2
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000200000000 R14: 0000381800000000 R15: 0000000000000000
</TASK>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240503143138.3562116-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 82b951e6fbd31d85ae7f4feb5f00ddd4c5d256e2 ]
If vfio_irq_ctx_alloc() failed will lead to 'name' memory leak.
Fixes: 18c198c96a81 ("vfio/pci: Create persistent INTx handler")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240415015029.3699844-1-yebin10@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 95feb3160eef0caa6018e175a5560b816aee8e79 upstream.
Due to an erratum with the SPR_DSA and SPR_IAX devices, it is not secure to assign
these devices to virtual machines. Add the PCI IDs of these devices to the VFIO
denylist to ensure that this is handled appropriately by the VFIO subsystem.
The SPR_DSA and SPR_IAX devices are on-SOC devices for the Sapphire Rapids
(and related) family of products that perform data movement and compression.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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[ Upstream commit 457f7308254756b6e4b8fc3876cb770dcf0e7cc7 ]
It's possible the migration file is accessed after reset when it has
been cleaned up, especially when it's initiated by the device. This is
because the driver doesn't rip out the filep when cleaning up it only
frees the related page structures and sets its local struct
pds_vfio_lm_file pointer to NULL. This can cause a NULL pointer
dereference, which is shown in the example below during a restore after
a device initiated reset:
BUG: kernel NULL pointer dereference, address: 000000000000000c
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:pds_vfio_get_file_page+0x5d/0xf0 [pds_vfio_pci]
[...]
Call Trace:
<TASK>
pds_vfio_restore_write+0xf6/0x160 [pds_vfio_pci]
vfs_write+0xc9/0x3f0
? __fget_light+0xc9/0x110
ksys_write+0xb5/0xf0
__x64_sys_write+0x1a/0x20
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]
Add a disabled flag to the driver's struct pds_vfio_lm_file that gets
set during cleanup. Then make sure to check the flag when the migration
file is accessed via its file_operations. By default this flag will be
false as the memory for struct pds_vfio_lm_file is kzalloc'd, which means
the struct pds_vfio_lm_file is enabled and accessible. Also, since the
file_operations and driver's migration file cleanup happen under the
protection of the same pds_vfio_lm_file.lock, using this flag is thread
safe.
Fixes: 8512ed256334 ("vfio/pds: Always clear the save/restore FDs on reset")
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20240308182149.22036-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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commit 7447d911af699a15f8d050dfcb7c680a86f87012 upstream.
The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
initially NULL and may become NULL if the user sets the trigger
eventfd to -1. The interrupt handler itself is guaranteed that
trigger is always valid between request_irq() and free_irq(), but
the loopback testing mechanisms to invoke the handler function
need to test the trigger. The triggering and setting ioctl paths
both make use of igate and are therefore mutually exclusive.
The vfio-fsl-mc driver does not make use of irqfds, nor does it
support any sort of masking operations, therefore unlike vfio-pci
and vfio-platform, the flow can remain essentially unchanged.
Cc: Diana Craciun <diana.craciun@oss.nxp.com>
Cc: <stable@vger.kernel.org>
Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-8-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 675daf435e9f8e5a5eab140a9864dfad6668b375 upstream.
The vfio-platform SET_IRQS ioctl currently allows loopback triggering of
an interrupt before a signaling eventfd has been configured by the user,
which thereby allows a NULL pointer dereference.
Rather than register the IRQ relative to a valid trigger, register all
IRQs in a disabled state in the device open path. This allows mask
operations on the IRQ to nest within the overall enable state governed
by a valid eventfd signal. This decouples @masked, protected by the
@locked spinlock from @trigger, protected via the @igate mutex.
In doing so, it's guaranteed that changes to @trigger cannot race the
IRQ handlers because the IRQ handler is synchronously disabled before
modifying the trigger, and loopback triggering of the IRQ via ioctl is
safe due to serialization with trigger changes via igate.
For compatibility, request_irq() failures are maintained to be local to
the SET_IRQS ioctl rather than a fatal error in the open device path.
This allows, for example, a userspace driver with polling mode support
to continue to work regardless of moving the request_irq() call site.
This necessarily blocks all SET_IRQS access to the failed index.
Cc: Eric Auger <eric.auger@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: 57f972e2b341 ("vfio/platform: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-7-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 18c198c96a815c962adc2b9b77909eec0be7df4d upstream.
A vulnerability exists where the eventfd for INTx signaling can be
deconfigured, which unregisters the IRQ handler but still allows
eventfds to be signaled with a NULL context through the SET_IRQS ioctl
or through unmask irqfd if the device interrupt is pending.
Ideally this could be solved with some additional locking; the igate
mutex serializes the ioctl and config space accesses, and the interrupt
handler is unregistered relative to the trigger, but the irqfd path
runs asynchronous to those. The igate mutex cannot be acquired from the
atomic context of the eventfd wake function. Disabling the irqfd
relative to the eventfd registration is potentially incompatible with
existing userspace.
As a result, the solution implemented here moves configuration of the
INTx interrupt handler to track the lifetime of the INTx context object
and irq_type configuration, rather than registration of a particular
trigger eventfd. Synchronization is added between the ioctl path and
eventfd_signal() wrapper such that the eventfd trigger can be
dynamically updated relative to in-flight interrupts or irqfd callbacks.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-5-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
commit b620ecbd17a03cacd06f014a5d3f3a11285ce053 upstream.
In order to synchronize changes that can affect the thread callback,
introduce an interface to force a flush of the inject workqueue. The
irqfd pointer is only valid under spinlock, but the workqueue cannot
be flushed under spinlock. Therefore the flush work for the irqfd is
queued under spinlock. The vfio_irqfd_cleanup_wq workqueue is re-used
for queuing this work such that flushing the workqueue is also ordered
relative to shutdown.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-4-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Stable-dep-of: 18c198c96a81 ("vfio/pci: Create persistent INTx handler")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit fcdc0d3d40bc26c105acf8467f7d9018970944ae ]
irqfds for mask and unmask that are not specifically disabled by the
user are leaked. Remove any irqfds during cleanup
Cc: Eric Auger <eric.auger@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: a7fa7c77cf15 ("vfio/platform: implement IRQ masking/unmasking via an eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-6-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 810cd4bb53456d0503cc4e7934e063835152c1b7 ]
Mask operations through config space changes to DisINTx may race INTx
configuration changes via ioctl. Create wrappers that add locking for
paths outside of the core interrupt code.
In particular, irq_type is updated holding igate, therefore testing
is_intx() requires holding igate. For example clearing DisINTx from
config space can otherwise race changes of the interrupt configuration.
This aligns interfaces which may trigger the INTx eventfd into two
camps, one side serialized by igate and the other only enabled while
INTx is configured. A subsequent patch introduces synchronization for
the latter flows.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-3-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit fe9a7082684eb059b925c535682e68c34d487d43 ]
Currently for devices requiring masking at the irqchip for INTx, ie.
devices without DisINTx support, the IRQ is enabled in request_irq()
and subsequently disabled as necessary to align with the masked status
flag. This presents a window where the interrupt could fire between
these events, resulting in the IRQ incrementing the disable depth twice.
This would be unrecoverable for a user since the masked flag prevents
nested enables through vfio.
Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
is never auto-enabled, then unmask as required.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 8512ed256334f6637fc0699ce794792c357544ec ]
After reset the VFIO device state will always be put in
VFIO_DEVICE_STATE_RUNNING, but the save/restore files will only be
cleared if the previous state was VFIO_DEVICE_STATE_ERROR. This
can/will cause the restore/save files to be leaked if/when the
migration state machine transitions through the states that
re-allocates these files. Fix this by always clearing the
restore/save files for resets.
Fixes: 7dabb1bcd177 ("vfio/pds: Add support for firmware recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240228003205.47311-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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[ Upstream commit 4bbcbc6ea2fa379632a24c14cfb47aa603816ac6 ]
For small bitmaps that aren't PAGE_SIZE aligned *and* that are less than
512 pages in bitmap length, use an extra page to be able to cover the
entire range e.g. [1M..3G] which would be iterated more efficiently in a
single iteration, rather than two.
Fixes: b058ea3ab5af ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-10-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d18411ec305728c6371806c4fb09be07016aad0b ]
iova_bitmap_mapped_length() don't deal correctly with the small bitmaps
(< 2M bitmaps) when the starting address isn't u64 aligned, leading to
skipping a tiny part of the IOVA range. This is materialized as not
marking data dirty that should otherwise have been.
Fix that by using a u8 * in the internal state of IOVA bitmap. Most of the
data structures use the type of the bitmap to adjust its indexes, thus
changing the type of the bitmap decreases the granularity of the bitmap
indexes.
Fixes: b058ea3ab5af ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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[ Upstream commit a4ab7dedaee0e39b15653c5fd0367e420739f7ef ]
Dirty IOMMU hugepages reported on a base page page-size granularity can
lead to an attempt to set dirty pages in the bitmap beyond the limits that
are pinned.
Bounds check the page index of the array we are trying to access is within
the limits before we kmap() and return otherwise.
While it is also a defensive check, this is also in preparation to defer
setting bits (outside the mapped range) to the next iteration(s) when the
pages become available.
Fixes: b058ea3ab5af ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit be12ad45e15b5ee0e2526a50266ba1d295d26a88 ]
When the optional PRE_COPY support was added to speed up the device
compatibility check, it failed to update the saving/resuming data
pointers based on the fd offset. This results in migration data
corruption and when the device gets started on the destination the
following error is reported in some cases,
[ 478.907684] arm-smmu-v3 arm-smmu-v3.2.auto: event 0x10 received:
[ 478.913691] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000310200000010
[ 478.919603] arm-smmu-v3 arm-smmu-v3.2.auto: 0x000002088000007f
[ 478.925515] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000000000000000
[ 478.931425] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000000000000000
[ 478.947552] hisi_zip 0000:31:00.0: qm_axi_rresp [error status=0x1] found
[ 478.955930] hisi_zip 0000:31:00.0: qm_db_timeout [error status=0x400] found
[ 478.955944] hisi_zip 0000:31:00.0: qm sq doorbell timeout in function 2
Fixes: d9a871e4a143 ("hisi_acc_vfio_pci: Introduce support for PRE_COPY state transitions")
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231120091406.780-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4004497cec3093d7b0087bc70709b45969fa07b6 ]
The incorrect check is being done for comparing the
iova/length being requested to sync. This can cause
the dirty sync operation to fail. Fix this by making
sure the iova offset added to the requested sync
length doesn't exceed the region_size.
Also, the region_start is assumed to always be at 0.
This can cause dirty tracking to fail because the
device/driver bitmap offset always starts at 0,
however, the region_start/iova may not. Fix this by
determining the iova offset from region_start to
determine the bitmap offset.
Fixes: f232836a9152 ("vfio/pds: Add support for dirty page tracking")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ae2667cd8a479bb5abd6e24c12fcc9ef5bc06d75 ]
The driver could possibly sleep while in atomic context resulting
in the following call trace while CONFIG_DEBUG_ATOMIC_SLEEP=y is
set:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2817, name: bash
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
Call Trace:
<TASK>
dump_stack_lvl+0x36/0x50
__might_resched+0x123/0x170
mutex_lock+0x1e/0x50
pds_vfio_put_lm_file+0x1e/0xa0 [pds_vfio_pci]
pds_vfio_put_save_file+0x19/0x30 [pds_vfio_pci]
pds_vfio_state_mutex_unlock+0x2e/0x80 [pds_vfio_pci]
pci_reset_function+0x4b/0x70
reset_store+0x5b/0xa0
kernfs_fop_write_iter+0x137/0x1d0
vfs_write+0x2de/0x410
ksys_write+0x5d/0xd0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
This can happen if pds_vfio_put_restore_file() and/or
pds_vfio_put_save_file() grab the mutex_lock(&lm_file->lock)
while the spin_lock(&pds_vfio->reset_lock) is held, which can
happen during while calling pds_vfio_state_mutex_unlock().
Fix this by changing the reset_lock to reset_mutex so there are no such
conerns. Also, make sure to destroy the reset_mutex in the driver specific
VFIO device release function.
This also fixes a spinlock bad magic BUG that was caused
by not calling spinlock_init() on the reset_lock. Since, the lock is
being changed to a mutex, make sure to call mutex_init() on it.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/kvm/1f9bc27b-3de9-4891-9687-ba2820c1b390@moroto.mountain/
Fixes: bb500dbe2ac6 ("vfio/pds: Add VFIO live migration support")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231122192532.25791-3-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 91aeb563bd4332e2988f8c0f64f125c4ecb5bcb3 ]
The following BUG was found when running on a kernel with
CONFIG_DEBUG_MUTEXES=y set:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
RIP: 0010:mutex_trylock+0x10d/0x120
Call Trace:
<TASK>
? __warn+0x85/0x140
? mutex_trylock+0x10d/0x120
? report_bug+0xfc/0x1e0
? handle_bug+0x3f/0x70
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? mutex_trylock+0x10d/0x120
? mutex_trylock+0x10d/0x120
pds_vfio_reset+0x3a/0x60 [pds_vfio_pci]
pci_reset_function+0x4b/0x70
reset_store+0x5b/0xa0
kernfs_fop_write_iter+0x137/0x1d0
vfs_write+0x2de/0x410
ksys_write+0x5d/0xd0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
As shown, lock->magic != lock. This is because
mutex_init(&pds_vfio->state_mutex) is called in the VFIO open path. So,
if a reset is initiated before the VFIO device is opened the mutex will
have never been initialized. Fix this by calling
mutex_init(&pds_vfio->state_mutex) in the VFIO init path.
Also, don't destroy the mutex on close because the device may
be re-opened, which would cause mutex to be uninitialized. Fix this by
implementing a driver specific vfio_device_ops.release callback that
destroys the mutex before calling vfio_pci_core_release_dev().
Fixes: bb500dbe2ac6 ("vfio/pds: Add VFIO live migration support")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231122192532.25791-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Inject fault while probing mdpy.ko, if kstrdup() of create_dir() fails in
kobject_add_internal() in kobject_init_and_add() in mdev_type_add()
in parent_create_sysfs_files(), it will return 0 and probe successfully.
And when rmmod mdpy.ko, the mdpy_dev_exit() will call
mdev_unregister_parent(), the mdev_type_remove() may traverse uninitialized
parent->types[i] in parent_remove_sysfs_files(), and it will cause
below null-ptr-deref.
If mdev_type_add() fails, return the error code and kset_unregister()
to fix the issue.
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 2 PID: 10215 Comm: rmmod Tainted: G W N 6.6.0-rc2+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__kobject_del+0x62/0x1c0
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8
RSP: 0018:ffff88810695fd30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1
R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000
R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660
FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0
DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea
DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
<TASK>
? die_addr+0x3d/0xa0
? exc_general_protection+0x144/0x220
? asm_exc_general_protection+0x22/0x30
? __kobject_del+0x62/0x1c0
kobject_del+0x32/0x50
parent_remove_sysfs_files+0xd6/0x170 [mdev]
mdev_unregister_parent+0xfb/0x190 [mdev]
? mdev_register_parent+0x270/0x270 [mdev]
? find_module_all+0x9d/0xe0
mdpy_dev_exit+0x17/0x63 [mdpy]
__do_sys_delete_module.constprop.0+0x2fa/0x4b0
? module_flags+0x300/0x300
? __fput+0x4e7/0xa00
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fbc813221b7
Code: 73 01 c3 48 8b 0d d1 8c 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 8c 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe780e0648 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 00007ffe780e06a8 RCX: 00007fbc813221b7
RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e214df9b58
RBP: 000055e214df9af0 R08: 00007ffe780df5c1 R09: 0000000000000000
R10: 00007fbc8139ecc0 R11: 0000000000000206 R12: 00007ffe780e0870
R13: 00007ffe780e0ed0 R14: 000055e214df9260 R15: 000055e214df9af0
</TASK>
Modules linked in: mdpy(-) mdev vfio_iommu_type1 vfio [last unloaded: mdpy]
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace 0000000000000000 ]---
RIP: 0010:__kobject_del+0x62/0x1c0
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8
RSP: 0018:ffff88810695fd30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1
R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000
R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660
FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0
DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea
DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 1 seconds..
Fixes: da44c340c4fe ("vfio/mdev: simplify mdev_type handling")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230918115551.1423193-1-ruanjinjie@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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The pci_physfn() helper exists to support cases where the physfn
field may not be compiled into the pci_dev structure. We've
declared this driver dependent on PCI_IOV to avoid this problem,
but regardless we should follow the precedent not to access this
field directly.
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230914021332.1929155-1-oushixiong@kylinos.cn
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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If PCI_ATS isn't set, then pdev->physfn is not defined.
it causes a compilation issue:
../drivers/vfio/pci/pds/vfio_dev.c:165:30: error: ‘struct pci_dev’ has no member named ‘physfn’; did you mean ‘is_physfn’?
165 | __func__, pci_dev_id(pdev->physfn), pci_id, vf_id,
| ^~~~~~
So adding PCI_IOV depends to select PCI_ATS.
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230906014942.1658769-1-oushixiong@kylinos.cn
Fixes: 63f77a7161a2 ("vfio/pds: register with the pds_core PF")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd
Pull iommufd updates from Jason Gunthorpe:
"On top of the vfio updates is built some new iommufd functionality:
- IOMMU_HWPT_ALLOC allows userspace to directly create the low level
IO Page table objects and affiliate them with IOAS objects that
hold the translation mapping. This is the basic functionality for
the normal IOMMU_DOMAIN_PAGING domains.
- VFIO_DEVICE_ATTACH_IOMMUFD_PT can be used to replace the current
translation. This is wired up to through all the layers down to the
driver so the driver has the ability to implement a hitless
replacement. This is necessary to fully support guest behaviors
when emulating HW (eg guest atomic change of translation)
- IOMMU_GET_HW_INFO returns information about the IOMMU driver HW
that owns a VFIO device. This includes support for the Intel iommu,
and patches have been posted for all the other server IOMMU.
Along the way are a number of internal items:
- New iommufd kernel APIs: iommufd_ctx_has_group(),
iommufd_device_to_ictx(), iommufd_device_to_id(),
iommufd_access_detach(), iommufd_ctx_from_fd(),
iommufd_device_replace()
- iommufd now internally tracks iommu_groups as it needs some
per-group data
- Reorganize how the internal hwpt allocation flows to have more
robust locking
- Improve the access interfaces to support detach and replace of an
IOAS from an access
- New selftests and a rework of how the selftests creates a mock
iommu driver to be more like a real iommu driver"
Link: https://lore.kernel.org/lkml/ZO%2FTe6LU1ENf58ZW@nvidia.com/
* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (34 commits)
iommufd/selftest: Don't leak the platform device memory when unloading the module
iommu/vt-d: Implement hw_info for iommu capability query
iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl
iommufd: Add IOMMU_GET_HW_INFO
iommu: Add new iommu op to get iommu hardware information
iommu: Move dev_iommu_ops() to private header
iommufd: Remove iommufd_ref_to_users()
iommufd/selftest: Make the mock iommu driver into a real driver
vfio: Support IO page table replacement
iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage
iommufd: Add iommufd_access_replace() API
iommufd: Use iommufd_access_change_ioas in iommufd_access_destroy_object
iommufd: Add iommufd_access_change_ioas(_id) helpers
iommufd: Allow passing in iopt_access_list_id to iopt_remove_access()
vfio: Do not allow !ops->dma_unmap in vfio_pin/unpin_pages()
iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC
iommufd/selftest: Return the real idev id from selftest mock_domain
iommufd: Add IOMMU_HWPT_ALLOC
iommufd/selftest: Test iommufd_device_replace()
iommufd: Make destroy_rwsem use a lock class per object type
...
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Pull VFIO updates from Alex Williamson:
- VFIO direct character device (cdev) interface support. This extracts
the vfio device fd from the container and group model, and is
intended to be the native uAPI for use with IOMMUFD (Yi Liu)
- Enhancements to the PCI hot reset interface in support of cdev usage
(Yi Liu)
- Fix a potential race between registering and unregistering vfio files
in the kvm-vfio interface and extend use of a lock to avoid extra
drop and acquires (Dmitry Torokhov)
- A new vfio-pci variant driver for the AMD/Pensando Distributed
Services Card (PDS) Ethernet device, supporting live migration (Brett
Creeley)
- Cleanups to remove redundant owner setup in cdx and fsl bus drivers,
and simplify driver init/exit in fsl code (Li Zetao)
- Fix uninitialized hole in data structure and pad capability
structures for alignment (Stefan Hajnoczi)
* tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio: (53 commits)
vfio/pds: Send type for SUSPEND_STATUS command
vfio/pds: fix return value in pds_vfio_get_lm_file()
pds_core: Fix function header descriptions
vfio: align capability structures
vfio/type1: fix cap_migration information leak
vfio/fsl-mc: Use module_fsl_mc_driver macro to simplify the code
vfio/cdx: Remove redundant initialization owner in vfio_cdx_driver
vfio/pds: Add Kconfig and documentation
vfio/pds: Add support for firmware recovery
vfio/pds: Add support for dirty page tracking
vfio/pds: Add VFIO live migration support
vfio/pds: register with the pds_core PF
pds_core: Require callers of register/unregister to pass PF drvdata
vfio/pds: Initial support for pds VFIO driver
vfio: Commonize combine_ranges for use in other VFIO drivers
kvm/vfio: avoid bouncing the mutex when adding and deleting groups
kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()
docs: vfio: Add vfio device cdev description
vfio: Compile vfio_group infrastructure optionally
vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev()
...
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Commit bb500dbe2ac6 ("vfio/pds: Add VFIO live migration support")
added live migration support for the pds-vfio-pci driver. When
sending the SUSPEND command to the device, the driver sets the
type of suspend (i.e. P2P or FULL). However, the driver isn't
sending the type of suspend for the SUSPEND_STATUS command, which
will result in failures. Fix this by also sending the suspend type
in the SUSPEND_STATUS command.
Fixes: bb500dbe2ac6 ("vfio/pds: Add VFIO live migration support")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230821184215.34564-1-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
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anon_inode_getfile() never returns NULL pointer, it will return
ERR_PTR() when it fails, so replace the check with IS_ERR().
Fixes: bb500dbe2ac6 ("vfio/pds: Add VFIO live migration support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20230819023716.3469037-1-yangyingliang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
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The VFIO_DEVICE_GET_INFO, VFIO_DEVICE_GET_REGION_INFO, and
VFIO_IOMMU_GET_INFO ioctls fill in an info struct followed by capability
structs:
+------+---------+---------+-----+
| info | caps[0] | caps[1] | ... |
+------+---------+---------+-----+
Both the info and capability struct sizes are not always multiples of
sizeof(u64), leaving u64 fields in later capability structs misaligned.
Userspace applications currently need to handle misalignment manually in
order to support CPU architectures and programming languages with strict
alignment requirements.
Make life easier for userspace by ensuring alignment in the kernel. This
is done by padding info struct definitions and by copying out zeroes
after capability structs that are not aligned.
The new layout is as follows:
+------+---------+---+---------+-----+
| info | caps[0] | 0 | caps[1] | ... |
+------+---------+---+---------+-----+
In this example caps[0] has a size that is not multiples of sizeof(u64),
so zero padding is added to align the subsequent structure.
Adding zero padding between structs does not break the uapi. The memory
layout is specified by the info.cap_offset and caps[i].next fields
filled in by the kernel. Applications use these field values to locate
structs and are therefore unaffected by the addition of zero padding.
Note that code that copies out info structs with padding is updated to
always zero the struct and copy out as many bytes as userspace
requested. This makes the code shorter and avoids potential information
leaks by ensuring padding is initialized.
Originally-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230809203144.2880050-1-stefanha@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
