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path: root/drivers/vfio
AgeCommit message (Collapse)Author
2012-08-22vfio: grab vfio_device reference *before* exposing the sucker via fd_install()Al Viro
It's not critical (anymore) since another thread closing the file will block on ->device_lock before it gets to dropping the final reference, but it's definitely cleaner that way... Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22vfio: get rid of vfio_device_put()/vfio_group_get_device* racesAl Viro
we really need to make sure that dropping the last reference happens under the group->device_lock; otherwise a loop (under device_lock) might find vfio_device instance that is being freed right now, has already dropped the last reference and waits on device_lock to exclude the sucker from the list. Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22vfio: get rid of open-coding kref_put_mutexAl Viro
Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22vfio: don't dereference after kfree...Al Viro
Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31vfio: Add PCI device driverAlex Williamson
Add PCI device support for VFIO. PCI devices expose regions for accessing config space, I/O port space, and MMIO areas of the device. PCI config access is virtualized in the kernel, allowing us to ensure the integrity of the system, by preventing various accesses while reducing duplicate support across various userspace drivers. I/O port supports read/write access while MMIO also supports mmap of sufficiently sized regions. Support for INTx, MSI, and MSI-X interrupts are provided using eventfds to userspace. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-07-31vfio: Type1 IOMMU implementationAlex Williamson
This VFIO IOMMU backend is designed primarily for AMD-Vi and Intel VT-d hardware, but is potentially usable by anything supporting similar mapping functionality. We arbitrarily call this a Type1 backend for lack of a better name. This backend has no IOVA or host memory mapping restrictions for the user and is optimized for relatively static mappings. Mapped areas are pinned into system memory. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-07-31vfio: VFIO coreAlex Williamson
VFIO is a secure user level driver for use with both virtual machines and user level drivers. VFIO makes use of IOMMU groups to ensure the isolation of devices in use, allowing unprivileged user access. It's intended that VFIO will replace KVM device assignment and UIO drivers (in cases where the target platform includes a sufficiently capable IOMMU). New in this version of VFIO is support for IOMMU groups managed through the IOMMU core as well as a rework of the API, removing the group merge interface. We now go back to a model more similar to original VFIO with UIOMMU support where the file descriptor obtained from /dev/vfio/vfio allows access to the IOMMU, but only after a group is added, avoiding the previous privilege issues with this type of model. IOMMU support is also now fully modular as IOMMUs have vastly different interface requirements on different platforms. VFIO users are able to query and initialize the IOMMU model of their choice. Please see the follow-on Documentation commit for further description and usage example. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>