get_pf_vdev() tries to check if a PF is a VFIO PF by looking at the driver:
if (pci_dev_driver(physfn) != pci_dev_driver(vdev->pdev)) {
However now that we have multiple VF and PF drivers this is no longer
reliable.
This means that security tests realted to vf_token can be skipped by
mixing and matching different VFIO PCI drivers.
Instead of trying to use the driver core to find the PF devices maintain a
linked list of all PF vfio_pci_core_device's that we have called
pci_enable_sriov() on.
When registering a VF just search the list to see if the PF is present and
record the match permanently in the struct. PCI core locking prevents a PF
from passing pci_disable_sriov() while VF drivers are attached so the VFIO
owned PF becomes a static property of the VF.
In common cases where vfio does not own the PF the global list remains
empty and the VF's pointer is statically NULL.
This also fixes a lockdep splat from recursive locking of the
vfio_group::device_lock between vfio_device_get_from_name() and
vfio_device_get_from_dev(). If the VF and PF share the same group this
would deadlock.
Fixes: ff53edf6d6 ("vfio/pci: Split the pci_driver code out of vfio_pci_core.c")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v3-876570980634+f2e8-vfio_vf_token_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Register private handler for pci_error_handlers.reset_done and update
state accordingly.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20220308184902.2242-10-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
VMs assigned with HiSilicon ACC VF devices can now perform live migration
if the VF devices are bind to the hisi_acc_vfio_pci driver.
Just like ACC PF/VF drivers this VFIO driver also make use of the HiSilicon
QM interface. QM stands for Queue Management which is a generic IP used by
ACC devices. It provides a generic PCIe interface for the CPU and the ACC
devices to share a group of queues.
QM integrated into an accelerator provides queue management service.
Queues can be assigned to PF and VFs, and queues can be controlled by
unified mailboxes and doorbells.
The QM driver (drivers/crypto/hisilicon/qm.c) provides generic
interfaces to ACC drivers to manage the QM.
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20220308184902.2242-9-shameerali.kolothum.thodi@huawei.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
HiSilicon ACC VF device BAR2 region consists of both functional register
space and migration control register space. Unnecessarily exposing the
migration BAR region to the Guest has the potential to prevent/corrupt
the Guest migration.
Hence, introduce a separate struct vfio_device_ops for migration support
which will override the ioctl/read/write/mmap methods to hide the
migration region and limit the Guest access only to the functional
register space.
This will be used in subsequent patches when we add migration support
to the driver.
Please note that it is OK to export the entire VF BAR if migration is
not supported or required as this cannot affect the PF configurations.
Reviewed-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220308184902.2242-6-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add a vendor-specific vfio_pci driver for HiSilicon ACC devices.
This will be extended in subsequent patches to add support for VFIO
live migration feature.
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220308184902.2242-5-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Register its own handler for pci_error_handlers.reset_done and update
state accordingly.
Link: https://lore.kernel.org/all/20220224142024.147653-16-yishaih@nvidia.com
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Expose vfio_pci_core_aer_err_detected() to be used by drivers as part of
their pci_error_handlers structure.
Next patch for mlx5 driver will use it.
Link: https://lore.kernel.org/all/20220224142024.147653-15-yishaih@nvidia.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>
This patch adds support for vfio_pci driver for mlx5 devices.
It uses vfio_pci_core to register to the VFIO subsystem and then
implements the mlx5 specific logic in the migration area.
The migration implementation follows the definition from uapi/vfio.h and
uses the mlx5 VF->PF command channel to achieve it.
This patch implements the suspend/resume flows.
Link: https://lore.kernel.org/all/20220224142024.147653-14-yishaih@nvidia.com
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Expose migration commands over the device, it includes: suspend, resume,
get vhca id, query/save/load state.
As part of this adds the APIs and data structure that are needed to manage
the migration data.
Link: https://lore.kernel.org/all/20220224142024.147653-13-yishaih@nvidia.com
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.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>
If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does
not have No_Soft_Reset bit set in its PMCSR config register), then the
current PCI state will be saved locally in
'vfio_pci_core_device::pm_save' during D0->D3hot transition and same
will be restored back during D3hot->D0 transition. For reset-related
functionalities, vfio driver uses PCI reset API's. These
API's internally change the PCI power state back to D0 first if
the device power state is non-D0. This state change to D0 will happen
without the involvement of vfio driver.
Let's consider the following example:
1. The device is in D3hot.
2. User invokes VFIO_DEVICE_RESET ioctl.
3. pci_try_reset_function() will be called which internally
invokes pci_dev_save_and_disable().
4. pci_set_power_state(dev, PCI_D0) will be called first.
5. pci_save_state() will happen then.
Now, for the devices which has NoSoftRst-, the pci_set_power_state()
can trigger soft reset and the original PCI config state will be lost
at step (4) and this state cannot be restored again. This original PCI
state can include any setting which is performed by SBIOS or host
linux kernel (for example LTR, ASPM L1 substates, etc.). When this
soft reset will be triggered, then all these settings will be reset,
and the device state saved at step (5) will also have this setting
cleared so it cannot be restored. Since the vfio driver only exposes
limited PCI capabilities to its user, so the vfio driver user also
won't have the option to save and restore these capabilities state
either and these original settings will be permanently lost.
For pci_reset_bus() also, we can have the above situation.
The other functions/devices can be in D3hot and the reset will change
the power state of all devices to D0 without the involvement of vfio
driver.
So, before calling any reset-related API's, we need to make sure that
the device state is D0. This is mainly to preserve the state around
soft reset.
For vfio_pci_core_disable(), we use __pci_reset_function_locked()
which internally can use pci_pm_reset() for the function reset.
pci_pm_reset() requires the device power state to be in D0, otherwise
it returns error.
This patch changes the device power state to D0 by invoking
vfio_pci_set_power_state() explicitly before calling any reset related
API's.
Fixes: 51ef3a004b ("vfio/pci: Restore device state on PM transition")
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220217122107.22434-3-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does
not have No_Soft_Reset bit set in its PMCSR config register), then
the current PCI state will be saved locally in
'vfio_pci_core_device::pm_save' during D0->D3hot transition and same
will be restored back during D3hot->D0 transition.
For saving the PCI state locally, pci_store_saved_state() is being
used and the pci_load_and_free_saved_state() will free the allocated
memory.
But for reset related IOCTLs, vfio driver calls PCI reset-related
API's which will internally change the PCI power state back to D0. So,
when the guest resumes, then it will get the current state as D0 and it
will skip the call to vfio_pci_set_power_state() for changing the
power state to D0 explicitly. In this case, the memory pointed by
'pm_save' will never be freed. In a malicious sequence, the state changing
to D3hot followed by VFIO_DEVICE_RESET/VFIO_DEVICE_PCI_HOT_RESET can be
run in a loop and it can cause an OOM situation.
This patch frees the earlier allocated memory first before overwriting
'pm_save' to prevent the mentioned memory leak.
Fixes: 51ef3a004b ("vfio/pci: Restore device state on PM transition")
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220217122107.22434-2-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Variables allocated by kvzalloc should not be freed by kfree.
Because they may be allocated by vmalloc.
So we replace kfree with kvfree here.
Fixes: d6a4c18566 ("vfio iommu: Implementation of ioctl for dirty pages tracking")
Signed-off-by: Jiacheng Shi <billsjc@sjtu.edu.cn>
Link: https://lore.kernel.org/r/20211212091600.2560-1-billsjc@sjtu.edu.cn
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Sparse warns:
sparse warnings: (new ones prefixed by >>)
>> drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned short [addressable] [usertype] val @@ got restricted __le16 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: expected unsigned short [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: got restricted __le16 [usertype]
>> drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned int [addressable] [usertype] val @@ got restricted __le32 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: expected unsigned int [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: got restricted __le32 [usertype]
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned short [addressable] [usertype] val @@ got restricted __le16 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: expected unsigned short [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: got restricted __le16 [usertype]
These are due to trying to use an unsigned to store the result of
a cpu_to_leXX() conversion. These are small variables, so pointer
tricks are wasteful and casting just generates different sparse
warnings. Store to and copy results from a separate little endian
variable.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202111290026.O3vehj03-lkp@intel.com/
Link: https://lore.kernel.org/r/163840226123.138003.7668320168896210328.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Storing a pointer to the MSI descriptor just to track the Linux interrupt
number is daft. Just store the interrupt number and be done with it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221815.207838579@linutronix.de
This is to fix incorrect pointer arithmetic which caused wrong
OpRegion version returned, then VM driver got error to get wanted
VBT block. We need to be safe to return correct data, so force
pointer type for byte access.
Fixes: 49ba1a2976 ("vfio/pci: Add OpRegion 2.0+ Extended VBT support.")
Cc: Colin Xu <colin.xu@gmail.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: "Xu, Terrence" <terrence.xu@intel.com>
Cc: "Gao, Fred" <fred.gao@intel.com>
Acked-by: Colin Xu <colin.xu@gmail.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://lore.kernel.org/r/20211125051328.3359902-1-zhenyuw@linux.intel.com
[aw: line wrap]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio.c abuses (misuses) "/**", which indicates the beginning of
kernel-doc notation in the kernel tree. This causes a bunch of
kernel-doc complaints about this source file, so quieten all of
them by changing all "/**" to "/*".
vfio.c:236: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* IOMMU driver registration
vfio.c:236: warning: missing initial short description on line:
* IOMMU driver registration
vfio.c:295: warning: expecting prototype for Container objects(). Prototype was for vfio_container_get() instead
vfio.c:317: warning: expecting prototype for Group objects(). Prototype was for __vfio_group_get_from_iommu() instead
vfio.c:496: warning: Function parameter or member 'device' not described in 'vfio_device_put'
vfio.c:496: warning: expecting prototype for Device objects(). Prototype was for vfio_device_put() instead
vfio.c:599: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Async device support
vfio.c:599: warning: missing initial short description on line:
* Async device support
vfio.c:693: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* VFIO driver API
vfio.c:693: warning: missing initial short description on line:
* VFIO driver API
vfio.c:835: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Get a reference to the vfio_device for a device. Even if the
vfio.c:835: warning: missing initial short description on line:
* Get a reference to the vfio_device for a device. Even if the
vfio.c:969: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* VFIO base fd, /dev/vfio/vfio
vfio.c:969: warning: missing initial short description on line:
* VFIO base fd, /dev/vfio/vfio
vfio.c:1187: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* VFIO Group fd, /dev/vfio/$GROUP
vfio.c:1187: warning: missing initial short description on line:
* VFIO Group fd, /dev/vfio/$GROUP
vfio.c:1540: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* VFIO Device fd
vfio.c:1540: warning: missing initial short description on line:
* VFIO Device fd
vfio.c:1615: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* External user API, exported by symbols to be linked dynamically.
vfio.c:1615: warning: missing initial short description on line:
* External user API, exported by symbols to be linked dynamically.
vfio.c:1663: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* External user API, exported by symbols to be linked dynamically.
vfio.c:1663: warning: missing initial short description on line:
* External user API, exported by symbols to be linked dynamically.
vfio.c:1742: warning: Function parameter or member 'caps' not described in 'vfio_info_cap_add'
vfio.c:1742: warning: Function parameter or member 'size' not described in 'vfio_info_cap_add'
vfio.c:1742: warning: Function parameter or member 'id' not described in 'vfio_info_cap_add'
vfio.c:1742: warning: Function parameter or member 'version' not described in 'vfio_info_cap_add'
vfio.c:1742: warning: expecting prototype for Sub(). Prototype was for vfio_info_cap_add() instead
vfio.c:2276: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Module/class support
vfio.c:2276: warning: missing initial short description on line:
* Module/class support
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/38a9cb92-a473-40bf-b8f9-85cc5cfc2da4@infradead.org
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Modernize how vfio is creating the group char dev and sysfs presence.
These days drivers with state should use cdev_device_add() and
cdev_device_del() to manage the cdev and sysfs lifetime.
This API requires the driver to put the struct device and struct cdev
inside its state struct (vfio_group), and then use the usual
device_initialize()/cdev_device_add()/cdev_device_del() sequence.
Split the code to make this possible:
- vfio_group_alloc()/vfio_group_release() are pair'd functions to
alloc/free the vfio_group. release is done under the struct device
kref.
- vfio_create_group()/vfio_group_put() are pairs that manage the
sysfs/cdev lifetime. Once the uses count is zero the vfio group's
userspace presence is destroyed.
- The IDR is replaced with an IDA. container_of(inode->i_cdev)
is used to get back to the vfio_group during fops open. The IDA
assigns unique minor numbers.
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/5-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The next patch adds a struct device to the struct vfio_group, and it is
confusing/bad practice to have two krefs in the same struct. This kref is
controlling the period when the vfio_group is registered in sysfs, and
visible in the internal lookup. Switch it to a refcount_t instead.
The refcount_dec_and_mutex_lock() is still required because we need
atomicity of the list searches and sysfs presence.
Reviewed-by: Liu Yi L <yi.l.liu@intel.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/4-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If vfio_create_group() searches the group list and returns an already
existing group it does not put back the iommu_group reference that the
caller passed in.
Change the semantic of vfio_create_group() to not move the reference in
from the caller, but instead obtain a new reference inside and leave the
caller's reference alone. The two callers must now call iommu_group_put().
This is an unlikely race as the only caller that could hit it has already
searched the group list before attempting to create the group.
Fixes: cba3345cc4 ("vfio: VFIO core")
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/3-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Split vfio_group_get_from_iommu() into __vfio_group_get_from_iommu() so
that vfio_create_group() can call it to consolidate this duplicated code.
Reviewed-by: Liu Yi L <yi.l.liu@intel.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/2-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
iommu_group_register_notifier()/iommu_group_unregister_notifier() are
built using a blocking_notifier_chain which integrates a rwsem. The
notifier function cannot be running outside its registration.
When considering how the notifier function interacts with create/destroy
of the group there are two fringe cases, the notifier starts before
list_add(&vfio.group_list) and the notifier runs after the kref
becomes 0.
Prior to vfio_create_group() unlocking and returning we have
container_users == 0
device_list == empty
And this cannot change until the mutex is unlocked.
After the kref goes to zero we must also have
container_users == 0
device_list == empty
Both are required because they are balanced operations and a 0 kref means
some caller became unbalanced. Add the missing assertion that
container_users must be zero as well.
These two facts are important because when checking each operation we see:
- IOMMU_GROUP_NOTIFY_ADD_DEVICE
Empty device_list avoids the WARN_ON in vfio_group_nb_add_dev()
0 container_users ends the call
- IOMMU_GROUP_NOTIFY_BOUND_DRIVER
0 container_users ends the call
Finally, we have IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER, which only deletes
items from the unbound list. During creation this list is empty, during
kref == 0 nothing can read this list, and it will be freed soon.
Since the vfio_group_release() doesn't hold the appropriate lock to
manipulate the unbound_list and could race with the notifier, move the
cleanup to directly before the kfree.
This allows deleting all of the deferred group put code.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Due to historical reason, some legacy shipped system doesn't follow
OpRegion 2.1 spec but still stick to OpRegion 2.0, in which the extended
VBT is not contiguous after OpRegion in physical address, but any
location pointed by RVDA via absolute address. Also although current
OpRegion 2.1+ systems appears that the extended VBT follows OpRegion,
RVDA is the relative address to OpRegion head, the extended VBT location
may change to non-contiguous to OpRegion. In both cases, it's impossible
to map a contiguous range to hold both OpRegion and the extended VBT and
expose via one vfio region.
The only difference between OpRegion 2.0 and 2.1 is where extended
VBT is stored: For 2.0, RVDA is the absolute address of extended VBT
while for 2.1, RVDA is the relative address of extended VBT to OpRegion
baes, and there is no other difference between OpRegion 2.0 and 2.1.
To support the non-contiguous region case as described, the updated read
op will patch OpRegion version and RVDA on-the-fly accordingly. So that
from vfio igd OpRegion view, only 2.1+ with contiguous extended VBT
after OpRegion is exposed, regardless the underneath host OpRegion is
2.0 or 2.1+. The mechanism makes it possible to support legacy OpRegion
2.0 extended VBT systems with on the market, and support OpRegion 2.1+
where the extended VBT isn't contiguous after OpRegion.
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Hang Yuan <hang.yuan@linux.intel.com>
Cc: Swee Yee Fonn <swee.yee.fonn@intel.com>
Cc: Fred Gao <fred.gao@intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Link: https://lore.kernel.org/r/20211012124855.52463-1-colin.xu@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
IS_IOMMU_CAP_DOMAIN_IN_CONTAINER just obsfucated the checks being
performed, so open code it in the callers.
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/20210924155705.4258-16-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The external_domain concept rather misleading and not actually needed.
Replace it with a list of emulated groups in struct vfio_iommu.
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/20210924155705.4258-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Ensure pgsize_bitmap is always valid by initializing it to PAGE_MASK
in vfio_iommu_type1_open and remove the now pointless update for
the external domain case in vfio_iommu_type1_attach_group, which was
just setting pgsize_bitmap to PAGE_MASK when only external domains
were attached.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210924155705.4258-14-hch@lst.de
[aw: s/ULONG_MAX/PAGE_MASK/ per discussion in link]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Unlike the the type1 IOMMU backend, the SPAPR one does not contain any
support for the magic non-IOMMU backed iommu_group used by mediated
devices, so reject them in ->attach_group.
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/20210924155705.4258-13-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Pass the group flags to ->attach_group and remove the messy check for
the bus type.
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/20210924155705.4258-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The iommu_device field in struct mdev_device has never been used
since it was added more than 2 years ago.
This is a manual revert of commit 7bd50f0cd2
("vfio/type1: Add domain at(de)taching group helpers").
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/20210924155705.4258-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.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>
Just pass a noiommu argument to vfio_create_group and set up the
->noiommu flag directly.
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/20210924155705.4258-7-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Split the actual noiommu group creation from vfio_iommu_group_get into a
new helper, and open code the rest of vfio_iommu_group_get in its only
caller. This creates an entirely separate and clear code path for the
noiommu group creation.
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/20210924155705.4258-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Factor out a helper to find or allocate the vfio_group to reduce the
spagetthi code in vfio_register_group_dev a little.
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/20210924155705.4258-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_noiommu_attach_group has two callers:
1) __vfio_container_attach_groups is called by vfio_ioctl_set_iommu,
which just called vfio_iommu_driver_allowed
2) vfio_group_set_container requires already checks ->noiommu on the
vfio_group, which is propagated from the iommudata in
vfio_create_group
so this check is entirely superflous and can be removed.
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/20210924155705.4258-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Factor out a little helper to make the checks for the noiommu driver less
ugly.
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/20210924155705.4258-3-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 when a fsl-mc device is reset, the entire DPRC container
is reset which is very inefficient because the devices within a
container will be reset multiple times.
Add support for individually resetting a device.
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20210922110530.24736-2-diana.craciun@oss.nxp.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The function prototype is missing an identifier name. Add one.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20210902212631.54260-1-colin.king@canonical.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Fix dma-valid return WAITED implementation (Anthony Yznaga)
- SPDX license cleanups (Cai Huoqing)
- Split vfio-pci-core from vfio-pci and enhance PCI driver matching
to support future vendor provided vfio-pci variants (Yishai Hadas,
Max Gurtovoy, Jason Gunthorpe)
- Replace duplicated reflck with core support for managing first
open, last close, and device sets (Jason Gunthorpe, Max Gurtovoy,
Yishai Hadas)
- Fix non-modular mdev support and don't nag about request callback
support (Christoph Hellwig)
- Add semaphore to protect instruction intercept handler and replace
open-coded locks in vfio-ap driver (Tony Krowiak)
- Convert vfio-ap to vfio_register_group_dev() API (Jason Gunthorpe)
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Merge tag 'vfio-v5.15-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Fix dma-valid return WAITED implementation (Anthony Yznaga)
- SPDX license cleanups (Cai Huoqing)
- Split vfio-pci-core from vfio-pci and enhance PCI driver matching to
support future vendor provided vfio-pci variants (Yishai Hadas, Max
Gurtovoy, Jason Gunthorpe)
- Replace duplicated reflck with core support for managing first open,
last close, and device sets (Jason Gunthorpe, Max Gurtovoy, Yishai
Hadas)
- Fix non-modular mdev support and don't nag about request callback
support (Christoph Hellwig)
- Add semaphore to protect instruction intercept handler and replace
open-coded locks in vfio-ap driver (Tony Krowiak)
- Convert vfio-ap to vfio_register_group_dev() API (Jason Gunthorpe)
* tag 'vfio-v5.15-rc1' of git://github.com/awilliam/linux-vfio: (37 commits)
vfio/pci: Introduce vfio_pci_core.ko
vfio: Use kconfig if XX/endif blocks instead of repeating 'depends on'
vfio: Use select for eventfd
PCI / VFIO: Add 'override_only' support for VFIO PCI sub system
PCI: Add 'override_only' field to struct pci_device_id
vfio/pci: Move module parameters to vfio_pci.c
vfio/pci: Move igd initialization to vfio_pci.c
vfio/pci: Split the pci_driver code out of vfio_pci_core.c
vfio/pci: Include vfio header in vfio_pci_core.h
vfio/pci: Rename ops functions to fit core namings
vfio/pci: Rename vfio_pci_device to vfio_pci_core_device
vfio/pci: Rename vfio_pci_private.h to vfio_pci_core.h
vfio/pci: Rename vfio_pci.c to vfio_pci_core.c
vfio/ap_ops: Convert to use vfio_register_group_dev()
s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification
s390/vfio-ap: r/w lock for PQAP interception handler function pointer
vfio/type1: Fix vfio_find_dma_valid return
vfio-pci/zdev: Remove repeated verbose license text
vfio: platform: reset: Convert to SPDX identifier
vfio: Remove struct vfio_device_ops open/release
...
Jason Gunthorpe