This replaces uses of vfio_file_iommu_group() which were only detecting if
the file is a VFIO file with no interest in the actual group.
The only remaning user of vfio_file_iommu_group() is in KVM for the SPAPR
stuff. It passes the iommu_group into the arch code through kvm for some
reason.
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/1-v2-15417f29324e+1c-vfio_group_disassociate_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>
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>
Introduce the DMA logging feature support in the vfio core layer.
It includes the processing of the device start/stop/report DMA logging
UAPIs and calling the relevant driver 'op' to do the work.
Specifically,
Upon start, the core translates the given input ranges into an interval
tree, checks for unexpected overlapping, non aligned ranges and then
pass the translated input to the driver for start tracking the given
ranges.
Upon report, the core translates the given input user space bitmap and
page size into an IOVA kernel bitmap iterator. Then it iterates it and
call the driver to set the corresponding bits for the dirtied pages in a
specific IOVA range.
Upon stop, the driver is called to stop the previous started tracking.
The next patches from the series will introduce the mlx5 driver
implementation for the logging ops.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.
Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.
And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.
For now, also update vfio_iommu_type1 to fit this new parameter too.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Following the updated vfio_pin/unpin_pages(), use the simpler "iova".
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-9-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA.
Among all three callers, there was only one caller possibly passing in
a non-contiguous PFN list, which is now ensured to have contiguous PFN
inputs too.
Pass in the starting address with "iova" alone to simplify things, so
callers no longer need to maintain a PFN list or to pin/unpin one page
at a time. This also allows VFIO to use more efficient implementations
of pin/unpin_pages.
For now, also update vfio_iommu_type1 to fit this new parameter too,
while keeping its input intact (being user_iova) since we don't want
to spend too much effort swapping its parameters and local variables
at that level.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There's only one caller that checks its return value with a WARN_ON_ONCE,
while all other callers don't check the return value at all. Above that,
an undo function should not fail. So, simplify the API to return void by
embedding similar WARN_ONs.
Also for users to pinpoint which condition fails, separate WARN_ON lines,
yet remove the "driver->ops->unpin_pages" check, since it's unreasonable
for callers to unpin on something totally random that wasn't even pinned.
And remove NULL pointer checks for they would trigger oops vs. warnings.
Note that npage is already validated in the vfio core, thus drop the same
check in the type1 code.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-2-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Instead of bouncing the function call to the driver op through a blocking
notifier just have the iommu layer call it directly.
Register each device that is being attached to the iommu with the lower
driver which then threads them on a linked list and calls the appropriate
driver op at the right time.
Currently the only use is if dma_unmap() is defined.
Also, fully lock all the debugging tests on the pinning path that a
dma_unmap is registered.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Instead of having drivers register the notifier with explicit code just
have them provide a dma_unmap callback op in their driver ops and rely on
the core code to wire it up.
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio core checks whether the driver sets some migration op (e.g.
set_state/get_state) and accordingly calls its op.
However, currently mlx5 driver sets the above ops without regards to its
migration caps.
This might lead to unexpected usage/Oops if user space may call to the
above ops even if the driver doesn't support migration. As for example,
the migration state_mutex is not initialized in that case.
The cleanest way to manage that seems to split the migration ops from
the main device ops, this will let the driver setting them separately
from the main ops when it's applicable.
As part of that, validate ops construction on registration and include a
check for VFIO_MIGRATION_STOP_COPY since the uAPI claims it must be set
in migration_flags.
HISI driver was changed as well to match this scheme.
This scheme may enable down the road to come with some extra group of
ops (e.g. DMA log) that can be set without regards to the other options
based on driver caps.
Fixes: 6fadb02126 ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220628155910.171454-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The use of 'extern' in function prototypes has been disrecommended in
the kernel coding style for several years now, remove them from all vfio
related files so contributors no longer need to decide between style and
consistency.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/165471414407.203056.474032786990662279.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Rather than relying on a notifier for associating the KVM with
the group, let's assume that the association has already been
made prior to device_open. The first time a device is opened
associate the group KVM with the device.
This fixes a user-triggerable oops in GVT.
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Zhi Wang <zhi.a.wang@intel.com>
Link: https://lore.kernel.org/r/20220519183311.582380-2-mjrosato@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
VFIO PCI does a security check as part of hot reset to prove that the user
has permission to manipulate all the devices that will be impacted by the
reset.
Use a new API vfio_file_has_dev() to perform this security check against
the struct file directly and remove the vfio_group from VFIO PCI.
Since VFIO PCI was the last user of vfio_group_get_external_user() and
vfio_group_put_external_user() remove it as well.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/8-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Just change the argument from struct vfio_group to struct file *.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Instead of a general extension check change the function into a limited
test if the iommu_domain has enforced coherency, which is the only thing
kvm needs to query.
Make the new op self contained by properly refcounting the container
before touching it.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_group_fops_open() ensures there is only ever one struct file open for
any struct vfio_group at any time:
/* Do we need multiple instances of the group open? Seems not. */
opened = atomic_cmpxchg(&group->opened, 0, 1);
if (opened) {
vfio_group_put(group);
return -EBUSY;
Therefor the struct file * can be used directly to search the list of VFIO
groups that KVM keeps instead of using the
vfio_external_group_match_file() callback to try to figure out if the
passed in FD matches the list or not.
Delete vfio_external_group_match_file().
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The only caller wants to get a pointer to the struct iommu_group
associated with the VFIO group file. Instead of returning the group ID
then searching sysfs for that string to get the struct iommu_group just
directly return the iommu_group pointer already held by the vfio_group
struct.
It already has a safe lifetime due to the struct file kref, the vfio_group
and thus the iommu_group cannot be destroyed while the group file is open.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The last user of this function is in PCI callbacks that want to convert
their struct pci_dev to a vfio_device. Instead of searching use the
vfio_device available trivially through the drvdata.
When a callback in the device_driver is called, the caller must hold the
device_lock() on dev. The purpose of the device_lock is to prevent
remove() from being called (see __device_release_driver), and allow the
driver to safely interact with its drvdata without races.
The PCI core correctly follows this and holds the device_lock() when
calling error_detected (see report_error_detected) and
sriov_configure (see sriov_numvfs_store).
Further, since the drvdata holds a positive refcount on the vfio_device
any access of the drvdata, under the device_lock(), from a driver callback
needs no further protection or refcounting.
Thus the remark in the vfio_device_get_from_dev() comment does not apply
here, VFIO PCI drivers all call vfio_unregister_group_dev() from their
remove callbacks under the device_lock() and cannot race with the
remaining callers.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-c841817a0349+8f-vfio_get_from_dev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that callers have been updated to use the vfio_device APIs the driver
facing group interface is no longer used, delete it:
- vfio_group_get_external_user_from_dev()
- vfio_group_pin_pages()
- vfio_group_unpin_pages()
- vfio_group_iommu_domain()
--
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Every caller has a readily available vfio_device pointer, use that instead
of passing in a generic struct device. Change vfio_dma_rw() to take in the
struct vfio_device and move the container users that would have been held
by vfio_group_get_external_user_from_dev() to vfio_dma_rw() directly, like
vfio_pin/unpin_pages().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Every caller has a readily available vfio_device pointer, use that instead
of passing in a generic struct device. The struct vfio_device already
contains the group we need so this avoids complexity, extra refcountings,
and a confusing lifecycle model.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
All callers have a struct vfio_device trivially available, pass it in
directly and avoid calling the expensive vfio_group_get_from_dev().
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The RUNNING_P2P state is designed to support multiple devices in the same
VM that are doing P2P transactions between themselves. When in RUNNING_P2P
the device must be able to accept incoming P2P transactions but should not
generate outgoing P2P transactions.
As an optional extension to the mandatory states it is defined as
in between STOP and RUNNING:
STOP -> RUNNING_P2P -> RUNNING -> RUNNING_P2P -> STOP
For drivers that are unable to support RUNNING_P2P the core code
silently merges RUNNING_P2P and RUNNING together. Unless driver support
is present, the new state cannot be used in SET_STATE.
Drivers that support this will be required to implement 4 FSM arcs
beyond the basic FSM. 2 of the basic FSM arcs become combination
transitions.
Compared to the v1 clarification, NDMA is redefined into FSM states and is
described in terms of the desired P2P quiescent behavior, noting that
halting all DMA is an acceptable implementation.
Link: https://lore.kernel.org/all/20220224142024.147653-11-yishaih@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Replace the existing region based migration protocol with an ioctl based
protocol. The two protocols have the same general semantic behaviors, but
the way the data is transported is changed.
This is the STOP_COPY portion of the new protocol, it defines the 5 states
for basic stop and copy migration and the protocol to move the migration
data in/out of the kernel.
Compared to the clarification of the v1 protocol Alex proposed:
https://lore.kernel.org/r/163909282574.728533.7460416142511440919.stgit@omen
This has a few deliberate functional differences:
- ERROR arcs allow the device function to remain unchanged.
- The protocol is not required to return to the original state on
transition failure. Instead userspace can execute an unwind back to
the original state, reset, or do something else without needing kernel
support. This simplifies the kernel design and should userspace choose
a policy like always reset, avoids doing useless work in the kernel
on error handling paths.
- PRE_COPY is made optional, userspace must discover it before using it.
This reflects the fact that the majority of drivers we are aware of
right now will not implement PRE_COPY.
- segmentation is not part of the data stream protocol, the receiver
does not have to reproduce the framing boundaries.
The hybrid FSM for the device_state is described as a Mealy machine by
documenting each of the arcs the driver is required to implement. Defining
the remaining set of old/new device_state transitions as 'combination
transitions' which are naturally defined as taking multiple FSM arcs along
the shortest path within the FSM's digraph allows a complete matrix of
transitions.
A new VFIO_DEVICE_FEATURE of VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE is
defined to replace writing to the device_state field in the region. This
allows returning a brand new FD whenever the requested transition opens
a data transfer session.
The VFIO core code implements the new feature and provides a helper
function to the driver. Using the helper the driver only has to
implement 6 of the FSM arcs and the other combination transitions are
elaborated consistently from those arcs.
A new VFIO_DEVICE_FEATURE of VFIO_DEVICE_FEATURE_MIGRATION is defined to
report the capability for migration and indicate which set of states and
arcs are supported by the device. The FSM provides a lot of flexibility to
make backwards compatible extensions but the VFIO_DEVICE_FEATURE also
allows for future breaking extensions for scenarios that cannot support
even the basic STOP_COPY requirements.
The VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE with the GET option (i.e.
VFIO_DEVICE_FEATURE_GET) can be used to read the current migration state
of the VFIO device.
Data transfer sessions are now carried over a file descriptor, instead of
the region. The FD functions for the lifetime of the data transfer
session. read() and write() transfer the data with normal Linux stream FD
semantics. This design allows future expansion to support poll(),
io_uring, and other performance optimizations.
The complicated mmap mode for data transfer is discarded as current qemu
doesn't take meaningful advantage of it, and the new qemu implementation
avoids substantially all the performance penalty of using a read() on the
region.
Link: https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Invoke a new device op 'device_feature' to handle just the data array
portion of the command. This lifts the ioctl validation to the core code
and makes it simpler for either the core code, or layered drivers, to
implement their own feature values.
Provide vfio_check_feature() to consolidate checking the flags/etc against
what the driver supports.
Link: https://lore.kernel.org/all/20220224142024.147653-9-yishaih@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Create a new private drivers/vfio/vfio.h header for the interface between
the VFIO core and the iommu drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The read, write and mmap methods are never implemented, so remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-9-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reuse the logic in vfio_noiommu_group_alloc to allocate a fake
single-device iommu group for mediated devices by factoring out a common
function, and replacing the noiommu boolean field in struct vfio_group
with an enum to distinguish the three different kinds of groups.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-8-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We don't need to hold a reference to the group in the driver as well as
obtain a reference to the same group as the first thing
vfio_register_group_dev() does.
Since the drivers never use the group move this all into the core code.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-2-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently the driver ops have an open/release pair that is called once
each time a device FD is opened or closed. Add an additional set of
open/close_device() ops which are called when the device FD is opened for
the first time and closed for the last time.
An analysis shows that all of the drivers require this semantic. Some are
open coding it as part of their reflck implementation, and some are just
buggy and miss it completely.
To retain the current semantics PCI and FSL depend on, introduce the idea
of a "device set" which is a grouping of vfio_device's that share the same
lock around opening.
The device set is established by providing a 'set_id' pointer. All
vfio_device's that provide the same pointer will be joined to the same
singleton memory and lock across the whole set. This effectively replaces
the oddly named reflck.
After conversion the set_id will be sourced from:
- A struct device from a fsl_mc_device (fsl)
- A struct pci_slot (pci)
- A struct pci_bus (pci)
- The struct vfio_device (everything)
The design ensures that the above pointers are live as long as the
vfio_device is registered, so they form reliable unique keys to group
vfio_devices into sets.
This implementation uses xarray instead of searching through the driver
core structures, which simplifies the somewhat tricky locking in this
area.
Following patches convert all the drivers.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This pairs with vfio_init_group_dev() and allows undoing any state that is
stored in the vfio_device unrelated to registration. Add appropriately
placed calls to all the drivers.
The following patch will use this to add pre-registration state for the
device set.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There are no longer any users, so it can go away. Everything is using
container_of now.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <14-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This is the standard kernel pattern, the ops associated with a struct get
the struct pointer in for typesafety. The expected design is to use
container_of to cleanly go from the subsystem level type to the driver
level type without having any type erasure in a void *.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <12-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
mdev gets little benefit because it doesn't actually do anything, however
it is the last user, so move the vfio_init/register/unregister_group_dev()
code here for now.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <10-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This makes the struct vfio_device part of the public interface so it
can be used with container_of and so forth, as is typical for a Linux
subystem.
This is the first step to bring some type-safety to the vfio interface by
allowing the replacement of 'void *' and 'struct device *' inputs with a
simple and clear 'struct vfio_device *'
For now the self-allocating vfio_add_group_dev() interface is kept so each
user can be updated as a separate patch.
The expected usage pattern is
driver core probe() function:
my_device = kzalloc(sizeof(*mydevice));
vfio_init_group_dev(&my_device->vdev, dev, ops, mydevice);
/* other driver specific prep */
vfio_register_group_dev(&my_device->vdev);
dev_set_drvdata(dev, my_device);
driver core remove() function:
my_device = dev_get_drvdata(dev);
vfio_unregister_group_dev(&my_device->vdev);
/* other driver specific tear down */
kfree(my_device);
Allowing the driver to be able to use the drvdata and vfio_device to go
to/from its own data.
The pattern also makes it clear that vfio_register_group_dev() must be
last in the sequence, as once it is called the core code can immediately
start calling ops. The init/register gap is provided to allow for the
driver to do setup before ops can be called and thus avoid races.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <3-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Define a vfio_iommu_driver_ops notify callback, for sending events to
the driver. Drivers are not required to provide the callback, and
may ignore any events. The handling of events is driver specific.
Define the CONTAINER_CLOSE event, called when the container's file
descriptor is closed. This event signifies that no further state changes
will occur via container ioctl's.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add the API for getting the domain from a vfio group. This could be used
by the physical device drivers which rely on the vfio/mdev framework for
mediated device user level access. The typical use case like below:
unsigned int pasid;
struct vfio_group *vfio_group;
struct iommu_domain *iommu_domain;
struct device *dev = mdev_dev(mdev);
struct device *iommu_device = mdev_get_iommu_device(dev);
if (!iommu_device ||
!iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
return -EINVAL;
vfio_group = vfio_group_get_external_user_from_dev(dev);
if (IS_ERR_OR_NULL(vfio_group))
return -EFAULT;
iommu_domain = vfio_group_iommu_domain(vfio_group);
if (IS_ERR_OR_NULL(iommu_domain)) {
vfio_group_put_external_user(vfio_group);
return -EFAULT;
}
pasid = iommu_aux_get_pasid(iommu_domain, iommu_device);
if (pasid < 0) {
vfio_group_put_external_user(vfio_group);
return -EFAULT;
}
/* Program device context with pasid value. */
...
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Added a check such that only singleton IOMMU groups can pin pages.
>From the point when vendor driver pins any pages, consider IOMMU group
dirty page scope to be limited to pinned pages.
To optimize to avoid walking list often, added flag
pinned_page_dirty_scope to indicate if all of the vfio_groups for each
vfio_domain in the domain_list dirty page scope is limited to pinned
pages. This flag is updated on first pinned pages request for that IOMMU
group and on attaching/detaching group.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Allow bus drivers to provide their own callback to match a device to
the user provided string.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_group_pin_pages() and vfio_group_unpin_pages() are introduced to
avoid inefficient search/check/ref/deref opertions associated with VFIO
group as those in each calling into vfio_pin_pages() and
vfio_unpin_pages().
VFIO group is taken as arg directly. The callers combine
search/check/ref/deref operations associated with VFIO group by calling
vfio_group_get_external_user()/vfio_group_get_external_user_from_dev()
beforehand, and vfio_group_put_external_user() afterwards.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_dma_rw will read/write a range of user space memory pointed to by
IOVA into/from a kernel buffer without enforcing pinning the user space
memory.
TODO: mark the IOVAs to user space memory dirty if they are written in
vfio_dma_rw().
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
external user calls vfio_group_get_external_user_from_dev() with a device
pointer to get the VFIO group associated with this device.
The VFIO group is checked to be vialbe and have IOMMU set. Then
container user counter is increased and VFIO group reference is hold
to prevent the VFIO group from disposal before external user exits.
when the external user finishes using of the VFIO group, it calls
vfio_group_put_external_user() to dereference the VFIO group and the
container user counter.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The vfio_info_add_capability() helper requires the caller to pass a
capability ID, which it then uses to fill in header fields, assuming
hard coded versions. This makes for an awkward and rigid interface.
The only thing we want this helper to do is allocate sufficient
space in the caps buffer and chain this capability into the list.
Reduce it to that simple task.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When CONFIG_EEH=y and CONFIG_VFIO_SPAPR_EEH=n, build fails with the
following:
drivers/vfio/pci/vfio_pci.o: In function `.vfio_pci_release':
vfio_pci.c:(.text+0xa98): undefined reference to `.vfio_spapr_pci_eeh_release'
drivers/vfio/pci/vfio_pci.o: In function `.vfio_pci_open':
vfio_pci.c:(.text+0x1420): undefined reference to `.vfio_spapr_pci_eeh_open'
In this case, vfio_pci.c should use the empty definitions of
vfio_spapr_pci_eeh_open and vfio_spapr_pci_eeh_release functions.
This patch fixes it by guarding these function definitions with
CONFIG_VFIO_SPAPR_EEH, the symbol that controls whether vfio_spapr_eeh.c is
built, which is where the non-empty versions of these functions are. We need to
make use of IS_ENABLED() macro because CONFIG_VFIO_SPAPR_EEH is a tristate
option.
This issue was found during a randconfig build. Logs are here:
http://kisskb.ellerman.id.au/kisskb/buildresult/12982362/
Signed-off-by: Murilo Opsfelder Araujo <mopsfelder@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Include Intel XXV710 in INTx workaround (Alex Williamson)
- Make use of ERR_CAST() for error return (Dan Carpenter)
- Fix vfio_group release deadlock from iommu notifier (Alex Williamson)
- Unset KVM-VFIO attributes only on group match (Alex Williamson)
- Fix release path group/file matching with KVM-VFIO (Alex Williamson)
- Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)
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Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Include Intel XXV710 in INTx workaround (Alex Williamson)
- Make use of ERR_CAST() for error return (Dan Carpenter)
- Fix vfio_group release deadlock from iommu notifier (Alex Williamson)
- Unset KVM-VFIO attributes only on group match (Alex Williamson)
- Fix release path group/file matching with KVM-VFIO (Alex Williamson)
- Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)
* tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio:
vfio: Remove unnecessary uses of vfio_container.group_lock
vfio: New external user group/file match
kvm-vfio: Decouple only when we match a group
vfio: Fix group release deadlock
vfio: Use ERR_CAST() instead of open coding it
vfio/pci: Add Intel XXV710 to hidden INTx devices
Jason Gunthorpe