Pull VFIO updates from Alex Williamson:
- Prune private items from vfio_pci_core.h to a new internal header,
fix missed function rename, and refactor vfio-pci interrupt defines
(Jason Gunthorpe)
- Create consistent naming and handling of ioctls with a function per
ioctl for vfio-pci and vfio group handling, use proper type args
where available (Jason Gunthorpe)
- Implement a set of low power device feature ioctls allowing userspace
to make use of power states such as D3cold where supported (Abhishek
Sahu)
- Remove device counter on vfio groups, which had restricted the page
pinning interface to singleton groups to account for limitations in
the type1 IOMMU backend. Document usage as limited to emulated IOMMU
devices, ie. traditional mdev devices where this restriction is
consistent (Jason Gunthorpe)
- Correct function prefix in hisi_acc driver incurred during previous
refactoring (Shameer Kolothum)
- Correct typo and remove redundant warning triggers in vfio-fsl driver
(Christophe JAILLET)
- Introduce device level DMA dirty tracking uAPI and implementation in
the mlx5 variant driver (Yishai Hadas & Joao Martins)
- Move much of the vfio_device life cycle management into vfio core,
simplifying and avoiding duplication across drivers. This also
facilitates adding a struct device to vfio_device which begins the
introduction of device rather than group level user support and fills
a gap allowing userspace identify devices as vfio capable without
implicit knowledge of the driver (Kevin Tian & Yi Liu)
- Split vfio container handling to a separate file, creating a more
well defined API between the core and container code, masking IOMMU
backend implementation from the core, allowing for an easier future
transition to an iommufd based implementation of the same (Jason
Gunthorpe)
- Attempt to resolve race accessing the iommu_group for a device
between vfio releasing DMA ownership and removal of the device from
the IOMMU driver. Follow-up with support to allow vfio_group to exist
with NULL iommu_group pointer to support existing userspace use cases
of holding the group file open (Jason Gunthorpe)
- Fix error code and hi/lo register manipulation issues in the hisi_acc
variant driver, along with various code cleanups (Longfang Liu)
- Fix a prior regression in GVT-g group teardown, resulting in
unreleased resources (Jason Gunthorpe)
- A significant cleanup and simplification of the mdev interface,
consolidating much of the open coded per driver sysfs interface
support into the mdev core (Christoph Hellwig)
- Simplification of tracking and locking around vfio_groups that fall
out from previous refactoring (Jason Gunthorpe)
- Replace trivial open coded f_ops tests with new helper (Alex
Williamson)
* tag 'vfio-v6.1-rc1' of https://github.com/awilliam/linux-vfio: (77 commits)
vfio: More vfio_file_is_group() use cases
vfio: Make the group FD disassociate from the iommu_group
vfio: Hold a reference to the iommu_group in kvm for SPAPR
vfio: Add vfio_file_is_group()
vfio: Change vfio_group->group_rwsem to a mutex
vfio: Remove the vfio_group->users and users_comp
vfio/mdev: add mdev available instance checking to the core
vfio/mdev: consolidate all the description sysfs into the core code
vfio/mdev: consolidate all the available_instance sysfs into the core code
vfio/mdev: consolidate all the name sysfs into the core code
vfio/mdev: consolidate all the device_api sysfs into the core code
vfio/mdev: remove mtype_get_parent_dev
vfio/mdev: remove mdev_parent_dev
vfio/mdev: unexport mdev_bus_type
vfio/mdev: remove mdev_from_dev
vfio/mdev: simplify mdev_type handling
vfio/mdev: embedd struct mdev_parent in the parent data structure
vfio/mdev: make mdev.h standalone includable
drm/i915/gvt: simplify vgpu configuration management
drm/i915/gvt: fix a memory leak in intel_gvt_init_vgpu_types
...
Allow the vfio_group struct to exist with a NULL iommu_group pointer. When
the pointer is NULL the vfio_group users promise not to touch the
iommu_group. This allows a driver to be hot unplugged while userspace is
keeping the group FD open.
Remove all the code waiting for the group FD to close.
This fixes a userspace regression where we learned that virtnodedevd
leaves a group FD open even though the /dev/ node for it has been deleted
and all the drivers for it unplugged.
Fixes: ca5f21b257 ("vfio: Follow a strict lifetime for struct iommu_group")
Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
SPAPR exists completely outside the normal iommu driver framework, the
groups it creates are fake and are only created to enable VFIO's uAPI.
Thus, it does not need to follow the iommu core rule that the iommu_group
will only be touched while a driver is attached.
Carry a group reference into KVM and have KVM directly manage the lifetime
of this object independently of VFIO. This means KVM no longer relies on
the vfio group file being valid to maintain the group reference.
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_parent. Implement it using correct locking, fixing mdpy.
Drivers just provide the value in the mdev_driver at registration time
and the core code takes care of maintaining it and exposing the value in
sysfs.
[hch: count instances per-parent instead of per-type, use an atomic_t
to avoid taking mdev_list_lock in the show method]
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The iommu_group comes from the struct device that a driver has been bound
to and then created a struct vfio_device against. To keep the iommu layer
sane we want to have a simple rule that only an attached driver should be
using the iommu API. Particularly only an attached driver should hold
ownership.
In VFIO's case since it uses the group APIs and it shares between
different drivers it is a bit more complicated, but the principle still
holds.
Solve this by waiting for all users of the vfio_group to stop before
allowing vfio_unregister_group_dev() to complete. This is done with a new
completion to know when the users go away and an additional refcount to
keep track of how many device drivers are sharing the vfio group. The last
driver to be unregistered will clean up the group.
This solves crashes in the S390 iommu driver that come because VFIO ends
up racing releasing ownership (which attaches the default iommu_domain to
the device) with the removal of that same device from the iommu
driver. This is a side case that iommu drivers should not have to cope
with.
iommu driver failed to attach the default/blocking domain
WARNING: CPU: 0 PID: 5082 at drivers/iommu/iommu.c:1961 iommu_detach_group+0x6c/0x80
Modules linked in: macvtap macvlan tap vfio_pci vfio_pci_core irqbypass vfio_virqfd kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink mlx5_ib sunrpc ib_uverbs ism smc uvdevice ib_core s390_trng eadm_sch tape_3590 tape tape_class vfio_ccw mdev vfio_iommu_type1 vfio zcrypt_cex4 sch_fq_codel configfs ghash_s390 prng chacha_s390 libchacha aes_s390 mlx5_core des_s390 libdes sha3_512_s390 nvme sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common nvme_core zfcp scsi_transport_fc pkey zcrypt rng_core autofs4
CPU: 0 PID: 5082 Comm: qemu-system-s39 Tainted: G W 6.0.0-rc3 #5
Hardware name: IBM 3931 A01 782 (LPAR)
Krnl PSW : 0704c00180000000 000000095bb10d28 (iommu_detach_group+0x70/0x80)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 0000000900000027 0000000000000039 000000095c97ffe0
00000000fffeffff 00000009fc290000 00000000af1fda50 00000000af590b58
00000000af1fdaf0 0000000135c7a320 0000000135e52258 0000000135e52200
00000000a29e8000 00000000af590b40 000000095bb10d24 0000038004b13c98
Krnl Code: 000000095bb10d18: c020003d56fc larl %r2,000000095c2bbb10
000000095bb10d1e: c0e50019d901 brasl %r14,000000095be4bf20
#000000095bb10d24: af000000 mc 0,0
>000000095bb10d28: b904002a lgr %r2,%r10
000000095bb10d2c: ebaff0a00004 lmg %r10,%r15,160(%r15)
000000095bb10d32: c0f4001aa867 brcl 15,000000095be65e00
000000095bb10d38: c004002168e0 brcl 0,000000095bf3def8
000000095bb10d3e: eb6ff0480024 stmg %r6,%r15,72(%r15)
Call Trace:
[<000000095bb10d28>] iommu_detach_group+0x70/0x80
([<000000095bb10d24>] iommu_detach_group+0x6c/0x80)
[<000003ff80243b0e>] vfio_iommu_type1_detach_group+0x136/0x6c8 [vfio_iommu_type1]
[<000003ff80137780>] __vfio_group_unset_container+0x58/0x158 [vfio]
[<000003ff80138a16>] vfio_group_fops_unl_ioctl+0x1b6/0x210 [vfio]
pci 0004:00:00.0: Removing from iommu group 4
[<000000095b5b62e8>] __s390x_sys_ioctl+0xc0/0x100
[<000000095be5d3b4>] __do_syscall+0x1d4/0x200
[<000000095be6c072>] system_call+0x82/0xb0
Last Breaking-Event-Address:
[<000000095be4bf80>] __warn_printk+0x60/0x68
It indicates that domain->ops->attach_dev() failed because the driver has
already passed the point of destructing the device.
Fixes: 9ac8545199 ("iommu: Fix use-after-free in iommu_release_device")
Reported-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v2-a3c5f4429e2a+55-iommu_group_lifetime_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
and replace kref. With it a 'vfio-dev/vfioX' node is created under the
sysfs path of the parent, indicating the device is bound to a vfio
driver, e.g.:
/sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0
It is also a preparatory step toward adding cdev for supporting future
device-oriented uAPI.
Add Documentation/ABI/testing/sysfs-devices-vfio-dev.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220921104401.38898-16-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
With the addition of vfio_put_device() now the names become confusing.
vfio_put_device() is clear from object life cycle p.o.v given kref.
vfio_device_put()/vfio_device_try_get() are helpers for tracking
users on a registered device.
Now rename them:
- vfio_device_put() -> vfio_device_put_registration()
- vfio_device_try_get() -> vfio_device_try_get_registration()
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220921104401.38898-15-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
ccw is the only exception which cannot use vfio_alloc_device() because
its private device structure is designed to serve both mdev and parent.
Life cycle of the parent is managed by css_driver so vfio_ccw_private
must be allocated/freed in css_driver probe/remove path instead of
conforming to vfio core life cycle for mdev.
Given that use a wait/completion scheme so the mdev remove path waits
after vfio_put_device() until receiving a completion notification from
@release. The completion indicates that all active references on
vfio_device have been released.
After that point although free of vfio_ccw_private is delayed to
css_driver it's at least guaranteed to have no parallel reference on
released vfio device part from other code paths.
memset() in @probe is removed. vfio_device is either already cleared
when probed for the first time or cleared in @release from last probe.
The right fix is to introduce separate structures for mdev and parent,
but this won't happen in short term per prior discussions.
Remove vfio_init/uninit_group_dev() as no user now.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220921104401.38898-14-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The idea is to let vfio core manage the vfio_device life cycle instead
of duplicating the logic cross drivers. This is also a preparatory
step for adding struct device into vfio_device.
New pair of helpers together with a kref in vfio_device:
- vfio_alloc_device()
- vfio_put_device()
Drivers can register @init/@release callbacks to manage any private
state wrapping the vfio_device.
However vfio-ccw doesn't fit this model due to a life cycle mess
that its private structure mixes both parent and mdev info hence must
be allocated/freed outside of the life cycle of vfio device.
Per prior discussions this won't be fixed in short term by IBM folks.
Instead of waiting for those modifications introduce another helper
vfio_init_device() so ccw can call it to initialize a pre-allocated
vfio_device.
Further implication of the ccw trick is that vfio_device cannot be
freed uniformly in vfio core. Instead, require *EVERY* driver to
implement @release and free vfio_device inside. Then ccw can choose
to delay the free at its own discretion.
Another trick down the road is that kvzalloc() is used to accommodate
the need of gvt which uses vzalloc() while all others use kzalloc().
So drivers should call a helper vfio_free_device() to free the
vfio_device instead of assuming that kfree() or vfree() is appliable.
Later once the ccw mess is fixed we can remove those tricks and
fully handle structure alloc/free in vfio core.
Existing vfio_{un}init_group_dev() will be deprecated after all
existing usages are converted to the new model.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220921104401.38898-2-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Pull VFIO fix from Alex Williamson:
- Fix zero page refcount leak (Alex Williamson)
* tag 'vfio-v6.0-rc5' of https://github.com/awilliam/linux-vfio:
vfio/type1: Unpin zero pages
Report dirty pages from tracker.
It includes:
Querying for dirty pages in a given IOVA range, this is done by
modifying the tracker into the reporting state and supplying the
required range.
Using the CQ event completion mechanism to be notified once data is
ready on the CQ/QP to be processed.
Once data is available turn on the corresponding bits in the bit map.
This functionality will be used as part of the 'log_read_and_clear'
driver callback in the next patches.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-9-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Init QP based resources for dirty tracking to be used upon start
logging.
It includes:
Creating the host and firmware RC QPs, move each of them to its expected
state based on the device specification, etc.
Creating the relevant resources which are needed by both QPs as of UAR,
PD, etc.
Creating the host receive side resources as of MKEY, CQ, receive WQEs,
etc.
The above resources are cleaned-up upon stop logging.
The tracker object that will be introduced by next patches will use
those resources.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-7-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
