user/sven/linux.git/include/uapi/linux/vfio.h, branch v6.1.38

vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR

2023-03-10T08:34:32Z

commit ef3a3f6a294ba65fd906a291553935881796f8a5 upstream. Disable the VFIO_UPDATE_VADDR capability if mediated devices are present. Their kernel threads could be blocked indefinitely by a misbehaving userland while trying to pin/unpin pages while vaddrs are being updated. Do not allow groups to be added to the container while vaddr's are invalid, so we never need to block user threads from pinning, and can delete the vaddr-waiting code in a subsequent patch. Fixes: c3cbab24db38 ("vfio/type1: implement interfaces to update vaddr") Cc: stable@vger.kernel.org Signed-off-by: Steve Sistare Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/1675184289-267876-2-git-send-email-steven.sistare@oracle.com Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio: Introduce DMA logging uAPIs

2022-09-08T18:59:00Z

DMA logging allows a device to internally record what DMAs the device is initiating and report them back to userspace. It is part of the VFIO migration infrastructure that allows implementing dirty page tracking during the pre copy phase of live migration. Only DMA WRITEs are logged, and this API is not connected to VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE. This patch introduces the DMA logging involved uAPIs. It uses the FEATURE ioctl with its GET/SET/PROBE options as of below. It exposes a PROBE option to detect if the device supports DMA logging. It exposes a SET option to start device DMA logging in given IOVAs ranges. It exposes a SET option to stop device DMA logging that was previously started. It exposes a GET option to read back and clear the device DMA log. Extra details exist as part of vfio.h per a specific option. Signed-off-by: Yishai Hadas Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20220908183448.195262-4-yishaih@nvidia.com Signed-off-by: Alex Williamson

vfio: Add the device features for the low power entry and exit

2022-09-01T21:29:11Z

This patch adds the following new device features for the low power entry and exit in the header file. The implementation for the same will be added in the subsequent patches. - VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY - VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP - VFIO_DEVICE_FEATURE_LOW_POWER_EXIT For vfio-pci based devices, with the standard PCI PM registers, all power states cannot be achieved. The platform-based power management needs to be involved to go into the lowest power state. For doing low power entry and exit with platform-based power management, these device features can be used. The entry device feature has two variants. These two variants are mainly to support the different behaviour for the 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. Some devices (for example NVIDIA VGA or 3D controller) require the user's guest driver involvement for each low-power entry. In the first variant, the host can return the device to low power automatically. The device will continue to attempt to reach low power until the low power exit feature is called. In the second variant, if the device exits low power due to an access, the host kernel will signal the user via the provided eventfd and will not return the device to low power without a subsequent call to one of the low power entry features. A call to the low power exit feature is optional if the user provided eventfd is signaled. These device features only support VFIO_DEVICE_FEATURE_SET and VFIO_DEVICE_FEATURE_PROBE operations. Signed-off-by: Abhishek Sahu Link: https://lore.kernel.org/r/20220829114850.4341-2-abhsahu@nvidia.com Signed-off-by: Alex Williamson

include/uapi/linux/vfio.h: Fix trivial typo - _IORW should be _IOWR instead

2022-05-16T18:39:43Z

There is no macro called _IORW, so use _IOWR in the comment instead. Signed-off-by: Thomas Huth Reviewed-by: Cornelia Huck Link: https://lore.kernel.org/r/20220516101202.88373-1-thuth@redhat.com Signed-off-by: Alex Williamson

vfio: Remove migration protocol v1 documentation

2022-03-03T11:01:19Z

v1 was never implemented and is replaced by v2. The old uAPI documentation is removed from the header file. The old uAPI definitions are still kept in the header file to ease transition for userspace copying these headers. They will be fully removed down the road. Link: https://lore.kernel.org/all/20220224142024.147653-12-yishaih@nvidia.com Signed-off-by: Jason Gunthorpe Tested-by: Shameer Kolothum Reviewed-by: Alex Williamson Reviewed-by: Cornelia Huck Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky

vfio: Extend the device migration protocol with RUNNING_P2P

2022-03-03T11:00:16Z

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 Tested-by: Shameer Kolothum Reviewed-by: Kevin Tian Reviewed-by: Alex Williamson Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky

vfio: Define device migration protocol v2

2022-03-03T10:57:39Z

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 Tested-by: Shameer Kolothum Reviewed-by: Kevin Tian Reviewed-by: Alex Williamson Reviewed-by: Cornelia Huck Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky

vfio/pci: Revert nvlink removal uAPI breakage

2021-05-05T16:19:41Z

Revert the uAPI changes from the below commit with notice that these regions and capabilities are no longer provided. Fixes: b392a1989170 ("vfio/pci: remove vfio_pci_nvlink2") Reported-by: Greg Kurz Signed-off-by: Alex Williamson Reviewed-by: Cornelia Huck Reviewed-by: Greg Kurz Tested-by: Greg Kurz Reviewed-by: Christoph Hellwig Message-Id: <162014341432.3807030.11054087109120670135.stgit@omen>

vfio/pci: remove vfio_pci_nvlink2

2021-04-06T17:54:13Z

This driver never had any open userspace (which for VFIO would include VM kernel drivers) that use it, and thus should never have been added by our normal userspace ABI rules. Signed-off-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Message-Id: <20210326061311.1497642-2-hch@lst.de> Signed-off-by: Alex Williamson

vfio: interfaces to update vaddr

2021-02-01T20:20:06Z

Define interfaces that allow the underlying memory object of an iova range to be mapped to a new host virtual address in the host process: - VFIO_DMA_UNMAP_FLAG_VADDR for VFIO_IOMMU_UNMAP_DMA - VFIO_DMA_MAP_FLAG_VADDR flag for VFIO_IOMMU_MAP_DMA - VFIO_UPDATE_VADDR extension for VFIO_CHECK_EXTENSION Unmap vaddr invalidates the host virtual address in an iova range, and blocks vfio translation of host virtual addresses. DMA to already-mapped pages continues. Map vaddr updates the base VA and resumes translation. See comments in uapi/linux/vfio.h for more details. Signed-off-by: Steve Sistare Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson