Tidy up @probe so all migration specific initialization logic is moved
to migration specific @init callback.
Remove vfio_pci_core_{un}init_device() given no user now.
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>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20220921104401.38898-5-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Also introduce two pci core helpers as @init/@release for pci drivers:
- vfio_pci_core_init_dev()
- vfio_pci_core_release_dev()
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/20220921104401.38898-3-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch implements VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP
device feature. In the VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY, if there is
any access for the VFIO device on the host side, then the device will
be moved out of the low power state without the user's guest driver
involvement. Once the device access has been finished, then the host
can move the device again into low power state. With the low power
entry happened through VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP,
the device will not be moved back into the low power state and
a notification will be sent to the user by triggering wakeup eventfd.
vfio_pci_core_pm_entry() will be called for both the variants of low
power feature entry so add an extra argument for wakeup eventfd context
and store locally in 'struct vfio_pci_core_device'.
For the entry happened without wakeup eventfd, all the exit related
handling will be done by the LOW_POWER_EXIT device feature only.
When the LOW_POWER_EXIT will be called, then the vfio core layer
vfio_device_pm_runtime_get() will increment the usage count and will
resume the device. In the driver runtime_resume callback, the
'pm_wake_eventfd_ctx' will be NULL. Then vfio_pci_core_pm_exit()
will call vfio_pci_runtime_pm_exit() and all the exit related handling
will be done.
For the entry happened with wakeup eventfd, in the driver resume
callback, eventfd will be triggered and all the exit related handling will
be done. When vfio_pci_runtime_pm_exit() will be called by
vfio_pci_core_pm_exit(), then it will return early.
But if the runtime suspend has not happened on the host side, then
all the exit related handling will be done in vfio_pci_core_pm_exit()
only.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-6-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently, if the runtime power management is enabled for vfio-pci
based devices in the guest OS, then the guest OS will do the register
write for PCI_PM_CTRL register. This write request will be handled in
vfio_pm_config_write() where it will do the actual register write of
PCI_PM_CTRL register. With this, the maximum D3hot state can be
achieved for low power. If we can use the runtime PM framework, then
we can achieve the D3cold state (on the supported systems) which will
help in saving maximum power.
1. D3cold state can't be achieved by writing PCI standard
PM config registers. This patch implements the following
newly added low power related device features:
- VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY
- VFIO_DEVICE_FEATURE_LOW_POWER_EXIT
The VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY feature will allow the
device to make use of low power platform states on the host
while the VFIO_DEVICE_FEATURE_LOW_POWER_EXIT will prevent
further use of those power states.
2. The vfio-pci driver uses runtime PM framework for low power entry and
exit. On the platforms where D3cold state is supported, the runtime
PM framework will put the device into D3cold otherwise, D3hot or some
other power state will be used.
There are various cases where the device will not go into the runtime
suspended state. For example,
- The runtime power management is disabled on the host side for
the device.
- The user keeps the device busy after calling LOW_POWER_ENTRY.
- There are dependent devices that are still in runtime active state.
For these cases, the device will be in the same power state that has
been configured by the user through PCI_PM_CTRL register.
3. The hypervisors can implement virtual ACPI methods. For example,
in guest linux OS if PCI device ACPI node has _PR3 and _PR0 power
resources with _ON/_OFF method, then guest linux OS invokes
the _OFF method during D3cold transition and then _ON during D0
transition. The hypervisor can tap these virtual ACPI calls and then
call the low power device feature IOCTL.
4. The 'pm_runtime_engaged' flag tracks the entry and exit to
runtime PM. This flag is protected with 'memory_lock' semaphore.
5. All the config and other region access are wrapped under
pm_runtime_resume_and_get() and pm_runtime_put(). So, if any
device access happens while the device is in the runtime suspended
state, then the device will be resumed first before access. Once the
access has been finished, then the device will again go into the
runtime suspended state.
6. The memory region access through mmap will not be allowed in the low
power state. Since __vfio_pci_memory_enabled() is a common function,
so check for 'pm_runtime_engaged' has been added explicitly in
vfio_pci_mmap_fault() to block only mmap'ed access.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-5-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch adds INTx handling during runtime suspend/resume.
All the suspend/resume related code for the user to put the device
into the low power state will be added in subsequent patches.
The INTx lines may be shared among devices. Whenever any INTx
interrupt comes for the VFIO devices, then vfio_intx_handler() will be
called for each device sharing the interrupt. Inside vfio_intx_handler(),
it calls pci_check_and_mask_intx() and checks if the interrupt has
been generated for the current device. Now, if the device is already
in the D3cold state, then the config space can not be read. Attempt
to read config space in D3cold state can cause system unresponsiveness
in a few systems. To prevent this, mask INTx in runtime suspend callback,
and unmask the same in runtime resume callback. If INTx has been already
masked, then no handling is needed in runtime suspend/resume callbacks.
'pm_intx_masked' tracks this, and vfio_pci_intx_mask() has been updated
to return true if the INTx vfio_pci_irq_ctx.masked value is changed
inside this function.
For the runtime suspend which is triggered for the no user of VFIO
device, the 'irq_type' will be VFIO_PCI_NUM_IRQS and these
callbacks won't do anything.
The MSI/MSI-X are not shared so similar handling should not be
needed for MSI/MSI-X. vfio_msihandler() triggers eventfd_signal()
without doing any device-specific config access. When the user performs
any config access or IOCTL after receiving the eventfd notification,
then the device will be moved to the D0 state first before
servicing any request.
Another option was to check this flag 'pm_intx_masked' inside
vfio_intx_handler() instead of masking the interrupts. This flag
is being set inside the runtime_suspend callback but the device
can be in non-D3cold state (for example, if the user has disabled D3cold
explicitly by sysfs, the D3cold is not supported in the platform, etc.).
Also, in D3cold supported case, the device will be in D0 till the
PCI core moves the device into D3cold. In this case, there is
a possibility that the device can generate an interrupt. Adding check
in the IRQ handler will not clear the IRQ status and the interrupt
line will still be asserted. This can cause interrupt flooding.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-4-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
As this is part of the vfio_pci_core component it should be called
vfio_pci_core_register_dev_region() like everything else exported from
this module.
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/2-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The header in include/linux should have only the exported interface for
other vfio_pci modules to use. Internal definitions for vfio_pci.ko
should be in a "priv" header along side the .c files.
Move the internal declarations out of vfio_pci_core.h. They either move to
vfio_pci_priv.h or to the C file that is the only user.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/1-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Cleanup use of extern in function prototypes (Alex Williamson)
- Simplify bus_type usage and convert to device IOMMU interfaces
(Robin Murphy)
- Check missed return value and fix comment typos (Bo Liu)
- Split migration ops from device ops and fix races in mlx5 migration
support (Yishai Hadas)
- Fix missed return value check in noiommu support (Liam Ni)
- Hardening to clear buffer pointer to avoid use-after-free (Schspa Shi)
- Remove requirement that only the same mm can unmap a previously
mapped range (Li Zhe)
- Adjust semaphore release vs device open counter (Yi Liu)
- Remove unused arg from SPAPR support code (Deming Wang)
- Rework vfio-ccw driver to better fit new mdev framework (Eric Farman,
Michael Kawano)
- Replace DMA unmap notifier with callbacks (Jason Gunthorpe)
- Clarify SPAPR support comment relative to iommu_ops (Alexey Kardashevskiy)
- Revise page pinning API towards compatibility with future iommufd support
(Nicolin Chen)
- Resolve issues in vfio-ccw, including use of DMA unmap callback
(Eric Farman)
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Merge tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Cleanup use of extern in function prototypes (Alex Williamson)
- Simplify bus_type usage and convert to device IOMMU interfaces (Robin
Murphy)
- Check missed return value and fix comment typos (Bo Liu)
- Split migration ops from device ops and fix races in mlx5 migration
support (Yishai Hadas)
- Fix missed return value check in noiommu support (Liam Ni)
- Hardening to clear buffer pointer to avoid use-after-free (Schspa
Shi)
- Remove requirement that only the same mm can unmap a previously
mapped range (Li Zhe)
- Adjust semaphore release vs device open counter (Yi Liu)
- Remove unused arg from SPAPR support code (Deming Wang)
- Rework vfio-ccw driver to better fit new mdev framework (Eric Farman,
Michael Kawano)
- Replace DMA unmap notifier with callbacks (Jason Gunthorpe)
- Clarify SPAPR support comment relative to iommu_ops (Alexey
Kardashevskiy)
- Revise page pinning API towards compatibility with future iommufd
support (Nicolin Chen)
- Resolve issues in vfio-ccw, including use of DMA unmap callback (Eric
Farman)
* tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfio: (40 commits)
vfio/pci: fix the wrong word
vfio/ccw: Check return code from subchannel quiesce
vfio/ccw: Remove FSM Close from remove handlers
vfio/ccw: Add length to DMA_UNMAP checks
vfio: Replace phys_pfn with pages for vfio_pin_pages()
vfio/ccw: Add kmap_local_page() for memcpy
vfio: Rename user_iova of vfio_dma_rw()
vfio/ccw: Change pa_pfn list to pa_iova list
vfio/ap: Change saved_pfn to saved_iova
vfio: Pass in starting IOVA to vfio_pin/unpin_pages API
vfio/ccw: Only pass in contiguous pages
vfio/ap: Pass in physical address of ind to ap_aqic()
drm/i915/gvt: Replace roundup with DIV_ROUND_UP
vfio: Make vfio_unpin_pages() return void
vfio/spapr_tce: Fix the comment
vfio: Replace the iommu notifier with a device list
vfio: Replace the DMA unmapping notifier with a callback
vfio/ccw: Move FSM open/close to MDEV open/close
vfio/ccw: Refactor vfio_ccw_mdev_reset
vfio/ccw: Create a CLOSE FSM event
...
During vfio-pci open_device, pass the KVM associated with the vfio group
(if one exists). This is needed in order to pass a special indicator
(GISA) to firmware to allow zPCI interpretation facilities to be used
for only the specific KVM associated with the vfio-pci device. During
vfio-pci close_device, unregister the notifier.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-18-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
The current contents of vfio-pci-zdev are today only useful in a KVM
environment; let's tie everything currently under vfio-pci-zdev to
this Kconfig statement and require KVM in this case, reducing complexity
(e.g. symbol lookups).
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-11-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.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>
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>
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>
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>
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>
Now that vfio_pci has been split into two source modules, one focusing on
the "struct pci_driver" (vfio_pci.c) and a toolbox library of code
(vfio_pci_core.c), complete the split and move them into two different
kernel modules.
As before vfio_pci.ko continues to present the same interface under sysfs
and this change will have no functional impact.
Splitting into another module and adding exports allows creating new HW
specific VFIO PCI drivers that can implement device specific
functionality, such as VFIO migration interfaces or specialized device
requirements.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-14-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Yi Liu