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Linux Kernel
3.7.1
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Linux Kernel
3.7.1
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#include <vfio.h>
Data Fields | |
| __u32 | argsz |
| __u32 | flags |
| __u32 | index |
| __u32 | count |
VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9, struct vfio_irq_info)
Retrieve information about a device IRQ. Caller provides struct vfio_irq_info with index value set. Caller sets argsz. Implementation of IRQ mapping is bus driver specific. Indexes using multiple IRQs are primarily intended to support MSI-like interrupt blocks. Zero count irq blocks may be used to describe unimplemented interrupt types.
The EVENTFD flag indicates the interrupt index supports eventfd based signaling.
The MASKABLE flags indicates the index supports MASK and UNMASK actions described below.
AUTOMASKED indicates that after signaling, the interrupt line is automatically masked by VFIO and the user needs to unmask the line to receive new interrupts. This is primarily intended to distinguish level triggered interrupts.
The NORESIZE flag indicates that the interrupt lines within the index are setup as a set and new subindexes cannot be enabled without first disabling the entire index. This is used for interrupts like PCI MSI and MSI-X where the driver may only use a subset of the available indexes, but VFIO needs to enable a specific number of vectors upfront. In the case of MSI-X, where the user can enable MSI-X and then add and unmask vectors, it's up to userspace to make the decision whether to allocate the maximum supported number of vectors or tear down setup and incrementally increase the vectors as each is enabled.
1.8.2