Device Model APIs¶
This section contains APIs for the SOS Device Model services. Sources for the Device Model are found in the devicemodel folder of the ACRN hypervisor GitHub repo
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group
acrn_virtio
virtio API
vhost APIs
APIs for virtio backend in kernel module.
Defines
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VRING_PAGE_BITS
¶
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VIRTIO_TYPE_NET
¶
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VIRTIO_TYPE_BLOCK
¶
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VIRTIO_TYPE_CONSOLE
¶
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VIRTIO_TYPE_ENTROPY
¶
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VIRTIO_TYPE_BALLOON
¶
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VIRTIO_TYPE_IOMEMORY
¶
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VIRTIO_TYPE_RPMSG
¶
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VIRTIO_TYPE_SCSI
¶
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VIRTIO_TYPE_9P
¶
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VIRTIO_TYPE_INPUT
¶
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VIRTIO_TYPE_RPMB
¶
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VIRTIO_TYPE_HECI
¶
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VIRTIO_TYPE_AUDIO
¶
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VIRTIO_TYPE_IPU
¶
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VIRTIO_TYPE_TSN
¶
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VIRTIO_TYPE_HYPERDMABUF
¶
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VIRTIO_TYPE_HDCP
¶
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VIRTIO_TYPE_COREU
¶
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VIRTIO_TYPE_GPIO
¶
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VIRTIO_TYPE_I2C
¶
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INTEL_VENDOR_ID
¶
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ORACLE_VENDOR_ID
¶
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VIRTIO_VENDOR
¶
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VIRTIO_DEV_NET
¶
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VIRTIO_DEV_BLOCK
¶
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VIRTIO_DEV_CONSOLE
¶
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VIRTIO_DEV_RANDOM
¶
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VIRTIO_DEV_RPMB
¶
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VIRTIO_DEV_HECI
¶
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VIRTIO_DEV_AUDIO
¶
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VIRTIO_DEV_IPU
¶
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VIRTIO_DEV_TSN
¶
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VIRTIO_DEV_HYPERDMABUF
¶
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VIRTIO_DEV_HDCP
¶
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VIRTIO_DEV_COREU
¶
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VIRTIO_DEV_GPIO
¶
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VIRTIO_DEV_I2C
¶
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VIRTIO_CONFIG_S_NEEDS_RESET
¶
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VIRTIO_PCI_ISR_QUEUES
¶
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VIRTIO_USE_MSIX
¶
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VIRTIO_EVENT_IDX
¶
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VIRTIO_BROKED
¶
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VIRTIO_LEGACY_PIO_BAR_IDX
¶
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VIRTIO_MODERN_PIO_BAR_IDX
¶
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VIRTIO_MODERN_MMIO_BAR_IDX
¶
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VIRTIO_CAP_COMMON_OFFSET
¶
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VIRTIO_CAP_COMMON_SIZE
¶
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VIRTIO_CAP_ISR_OFFSET
¶
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VIRTIO_CAP_ISR_SIZE
¶
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VIRTIO_CAP_DEVICE_OFFSET
¶
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VIRTIO_CAP_DEVICE_SIZE
¶
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VIRTIO_CAP_NOTIFY_OFFSET
¶
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VIRTIO_CAP_NOTIFY_SIZE
¶
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VIRTIO_MODERN_MEM_BAR_SIZE
¶
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VIRTIO_MODERN_NOTIFY_OFF_MULT
¶
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VIRTIO_PCI_CAP_COMMON_CFG
¶
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VIRTIO_PCI_CAP_NOTIFY_CFG
¶
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VIRTIO_PCI_CAP_ISR_CFG
¶
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VIRTIO_PCI_CAP_DEVICE_CFG
¶
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VIRTIO_PCI_CAP_PCI_CFG
¶
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VIRTIO_BASE_LOCK
(vb)¶
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VIRTIO_BASE_UNLOCK
(vb)¶
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VQ_ALLOC
¶
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VQ_BROKED
¶
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VQ_AVAIL_EVENT_IDX
(vq)¶
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VQ_USED_EVENT_IDX
(vq)¶
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VIRTIO_SUCCESS
¶
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VIRTIO_ERROR_REENTER
¶
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VIRTIO_ERROR_FD_OPEN_FAILED
¶
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VIRTIO_ERROR_MEM_ALLOC_FAILED
¶
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VIRTIO_ERROR_START
¶
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VIRTIO_ERROR_GENERAL
¶
Enums
Functions
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static bool
vq_ring_ready
(struct virtio_vq_info *vq)¶ Is this ring ready for I/O?
- Return
- false on not ready and true on ready.
- Parameters
vq
: Pointer to struct virtio_vq_info.
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static bool
vq_has_descs
(struct virtio_vq_info *vq)¶ Are there “available” descriptors?
This does not count how many, just returns true if there is any.
- Return
- false on not available and true on available.
- Parameters
vq
: Pointer to struct virtio_vq_info.
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static void
vq_interrupt
(struct virtio_base *vb, struct virtio_vq_info *vq)¶ Deliver an interrupt to guest on the given virtqueue.
The interrupt could be MSI-X or a generic MSI interrupt.
- Return
- None
- Parameters
vb
: Pointer to struct virtio_base.vq
: Pointer to struct virtio_vq_info.
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static void
virtio_config_changed
(struct virtio_base *vb)¶ Deliver an config changed interrupt to guest.
MSI-X or a generic MSI interrupt with config changed event.
- Return
- None
- Parameters
vb
: Pointer to struct virtio_base.
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void
virtio_linkup
(struct virtio_base *base, struct virtio_ops *vops, void *pci_virtio_dev, struct pci_vdev *dev, struct virtio_vq_info *queues, int backend_type)¶ Link a virtio_base to its constants, the virtio device, and the PCI emulation.
- Return
- None
- Parameters
base
: Pointer to struct virtio_base.vops
: Pointer to struct virtio_ops.pci_virtio_dev
: Pointer to instance of certain virtio device.dev
: Pointer to struct pci_vdev which emulates a PCI device.queues
: Pointer to struct virtio_vq_info, normally an array.backend_type
: can be VBSU, VBSK or VHOST
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int
acrn_parse_virtio_poll_interval
(const char *optarg)¶ Get the virtio poll parameters.
- Return
- fail -1 success 0
- Parameters
optarg
: Pointer to parameters string.
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int
virtio_interrupt_init
(struct virtio_base *base, int use_msix)¶ Initialize MSI-X vector capabilities if we’re to use MSI-X, or MSI capabilities if not.
Wrapper function for virtio_intr_init() for cases we directly use BAR 1 for MSI-X capabilities.
- Return
- 0 on success and non-zero on fail.
- Parameters
base
: Pointer to struct virtio_base.use_msix
: If using MSI-X.
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int
virtio_intr_init
(struct virtio_base *base, int barnum, int use_msix)¶ Initialize MSI-X vector capabilities if we’re to use MSI-X, or MSI capabilities if not.
We assume we want one MSI-X vector per queue, here, plus one for the config vec.
- Return
- 0 on success and non-zero on fail.
- Parameters
base
: Pointer to struct virtio_base.barnum
: Which BAR[0..5] to use.use_msix
: If using MSI-X.
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void
virtio_reset_dev
(struct virtio_base *base)¶ Reset device (device-wide).
This erases all queues, i.e., all the queues become invalid. But we don’t wipe out the internal pointers, by just clearing the VQ_ALLOC flag.
It resets negotiated features to “none”. If MSI-X is enabled, this also resets all the vectors to NO_VECTOR.
- Return
- None
- Parameters
base
: Pointer to struct virtio_base.
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void
virtio_set_io_bar
(struct virtio_base *base, int barnum)¶ Set I/O BAR (usually 0) to map PCI config registers.
- Return
- None
- Parameters
base
: Pointer to struct virtio_base.barnum
: Which BAR[0..5] to use.
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int
vq_getchain
(struct virtio_vq_info *vq, uint16_t *pidx, struct iovec *iov, int n_iov, uint16_t *flags)¶ Walk through the chain of descriptors involved in a request and put them into a given iov[] array.
- Return
- number of descriptors.
- Parameters
vq
: Pointer to struct virtio_vq_info.pidx
: Pointer to available ring position.iov
: Pointer to iov[] array prepared by caller.n_iov
: Size of iov[] array.flags
: Pointer to a uint16_t array which will contain flag of each descriptor.
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void
vq_retchain
(struct virtio_vq_info *vq)¶ Return the currently-first request chain back to the available ring.
- Return
- None
- Parameters
vq
: Pointer to struct virtio_vq_info.
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void
vq_relchain
(struct virtio_vq_info *vq, uint16_t idx, uint32_t iolen)¶ Return specified request chain to the guest, setting its I/O length to the provided value.
- Return
- None
- Parameters
vq
: Pointer to struct virtio_vq_info.idx
: Pointer to available ring position, returned by vq_getchain().iolen
: Number of data bytes to be returned to frontend.
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void
vq_endchains
(struct virtio_vq_info *vq, int used_all_avail)¶ Driver has finished processing “available” chains and calling vq_relchain on each one.
If driver used all the available chains, used_all_avail need to be set to 1.
- Return
- None
- Parameters
vq
: Pointer to struct virtio_vq_info.used_all_avail
: Flag indicating if driver used all available chains.
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void
vq_clear_used_ring_flags
(struct virtio_base *base, struct virtio_vq_info *vq)¶ Helper function for clearing used ring flags.
Driver should always use this helper function to clear used ring flags. For virtio poll mode, in order to avoid trap, we should never really clear used ring flags.
- Return
- None
- Parameters
base
: Pointer to struct virtio_base.vq
: Pointer to struct virtio_vq_info.
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uint64_t
virtio_pci_read
(struct vmctx *ctx, int vcpu, struct pci_vdev *dev, int baridx, uint64_t offset, int size)¶ Handle PCI configuration space reads.
Handle virtio standard register reads, and dispatch other reads to actual virtio device driver.
- Return
- register value.
- Parameters
ctx
: Pointer to struct vmctx representing VM context.vcpu
: VCPU ID.dev
: Pointer to struct pci_vdev which emulates a PCI device.baridx
: Which BAR[0..5] to use.offset
: Register offset in bytes within a BAR region.size
: Access range in bytes.
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void
virtio_pci_write
(struct vmctx *ctx, int vcpu, struct pci_vdev *dev, int baridx, uint64_t offset, int size, uint64_t value)¶ Handle PCI configuration space writes.
Handle virtio standard register writes, and dispatch other writes to actual virtio device driver.
- Return
- None
- Parameters
ctx
: Pointer to struct vmctx representing VM context.vcpu
: VCPU ID.dev
: Pointer to struct pci_vdev which emulates a PCI device.baridx
: Which BAR[0..5] to use.offset
: Register offset in bytes within a BAR region.size
: Access range in bytes.value
: Data value to be written into register.
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int
virtio_set_modern_bar
(struct virtio_base *base, bool use_notify_pio)¶ Set modern BAR (usually 4) to map PCI config registers.
Set modern MMIO BAR (usually 4) to map virtio 1.0 capabilities and optional set modern PIO BAR (usually 2) to map notify capability. This interface is only valid for modern virtio.
- Return
- 0 on success and non-zero on fail.
- Parameters
base
: Pointer to struct virtio_base.use_notify_pio
: Whether use pio for notify capability.
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int
vbs_kernel_reset
(int fd)¶ Virtio kernel module reset.
- Return
- 0 on OK and non-zero on error.
- Parameters
fd
: File descriptor representing virtio backend in kernel module.
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int
vbs_kernel_start
(int fd, struct vbs_dev_info *dev, struct vbs_vqs_info *vqs)¶ Virtio kernel module start.
- Return
- 0 on OK and non-zero on error.
- Parameters
fd
: File descriptor representing virtio backend in kernel module.dev
: Pointer to struct vbs_dev_info.vqs
: Pointer to struct vbs_vqs_info.
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int
vbs_kernel_stop
(int fd)¶ Virtio kernel module stop.
- Return
- 0 on OK and non-zero on error.
- Parameters
fd
: File descriptor representing virtio backend in kernel module.
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int
vhost_dev_init
(struct vhost_dev *vdev, struct virtio_base *base, int fd, int vq_idx, uint64_t vhost_features, uint64_t vhost_ext_features, uint32_t busyloop_timeout)¶ vhost_dev initialization.
This interface is called to initialize the vhost_dev. It must be called before the actual feature negotiation with the guest OS starts.
- Return
- 0 on success and -1 on failure.
- Parameters
vdev
: Pointer to struct vhost_dev.base
: Pointer to struct virtio_base.fd
: fd of the vhost chardev.vq_idx
: The first virtqueue which would be used by this vhost dev.vhost_features
: Subset of vhost features which would be enabled.vhost_ext_features
: Specific vhost internal features to be enabled.busyloop_timeout
: Busy loop timeout in us.
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int
vhost_dev_deinit
(struct vhost_dev *vdev)¶ vhost_dev cleanup.
This interface is called to cleanup the vhost_dev.
- Return
- 0 on success and -1 on failure.
- Parameters
vdev
: Pointer to struct vhost_dev.
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int
vhost_dev_start
(struct vhost_dev *vdev)¶ start vhost data plane.
This interface is called to start the data plane in vhost.
- Return
- 0 on success and -1 on failure.
- Parameters
vdev
: Pointer to struct vhost_dev.
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int
vhost_dev_stop
(struct vhost_dev *vdev)¶ stop vhost data plane.
This interface is called to stop the data plane in vhost.
- Return
- 0 on success and -1 on failure.
- Parameters
vdev
: Pointer to struct vhost_dev.
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int
vhost_net_set_backend
(struct vhost_dev *vdev, int backend_fd)¶ set backend fd of vhost net.
This interface is called to set the backend fd (for example tap fd) to vhost.
- Return
- 0 on success and -1 on failure.
- Parameters
vdev
: Pointer to struct vhost_dev.backend_fd
: fd of backend (for example tap fd).
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struct
virtio_base
¶ - #include <virtio.h>
Base component to any virtio device.
Public Members
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struct virtio_ops *
vops
¶ virtio operations
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int
flags
¶ VIRTIO_* flags from above
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pthread_mutex_t *
mtx
¶ POSIX mutex, if any
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struct pci_vdev *
dev
¶ PCI device instance
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uint64_t
negotiated_caps
¶ negotiated capabilities
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uint64_t
device_caps
¶ device capabilities
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struct virtio_vq_info *
queues
¶ one per nvq
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int
curq
¶ current queue
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uint8_t
status
¶ value from last status write
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uint8_t
isr
¶ ISR flags, if not MSI-X
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uint16_t
msix_cfg_idx
¶ MSI-X vector for config event
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uint32_t
legacy_pio_bar_idx
¶ index of legacy pio bar
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uint32_t
modern_pio_bar_idx
¶ index of modern pio bar
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uint32_t
modern_mmio_bar_idx
¶ index of modern mmio bar
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uint8_t
config_generation
¶ configuration generation
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uint32_t
device_feature_select
¶ current selected device feature
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uint32_t
driver_feature_select
¶ current selected guest feature
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int
cfg_coff
¶ PCI cfg access capability offset
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int
backend_type
¶ VBSU, VBSK or VHOST
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struct acrn_timer
polling_timer
¶ timer for polling mode
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int
polling_in_progress
¶ The polling status
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struct virtio_ops *
-
struct
virtio_ops
¶ - #include <virtio.h>
Virtio specific operation functions for this type of virtio device.
Public Members
-
const char *
name
¶ name of driver (for diagnostics)
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int
nvq
¶ number of virtual queues
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size_t
cfgsize
¶ size of dev-specific config regs
-
void (*
reset
)(void *)¶ called on virtual device reset
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void (*
qnotify
)(void *, struct virtio_vq_info *)¶ called on QNOTIFY if no VQ notify
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int (*
cfgread
)(void *, int, int, uint32_t *)¶ to read config regs
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int (*
cfgwrite
)(void *, int, int, uint32_t)¶ to write config regs
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void (*
apply_features
)(void *, uint64_t)¶ to apply negotiated features
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void (*
set_status
)(void *, uint64_t)¶ called to set device status
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const char *
-
struct
virtio_vq_info
¶ - #include <virtio.h>
Virtqueue data structure.
Data structure allocated (statically) per virtual queue.
Drivers may change qsize after a reset. When the guest OS requests a device reset, the hypervisor first calls vb->vo->reset(); then the data structure below is reinitialized (for each virtqueue: vb->vo->nvq).
The remaining fields should only be fussed-with by the generic code.
Note: the addresses of desc, avail, and vq_used are all computable from each other, but it’s a lot simpler if we just keep a pointer to each one. The event indices are similarly (but more easily) computable, and this time we’ll compute them: they’re just XX_ring[N].
Public Members
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uint16_t
qsize
¶ size of this queue (a power of 2)
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void (*
notify
)(void *, struct virtio_vq_info *)¶ called instead of notify, if not NULL
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struct virtio_base *
base
¶ backpointer to virtio_base
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uint16_t
num
¶ the num’th queue in the virtio_base
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uint16_t
flags
¶ flags (see above)
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uint16_t
last_avail
¶ a recent value of avail->idx
-
uint16_t
save_used
¶ saved used->idx; see vq_endchains
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uint16_t
msix_idx
¶ MSI-X index, or VIRTIO_MSI_NO_VECTOR
-
uint32_t
pfn
¶ PFN of virt queue (not shifted!)
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volatile struct vring_desc *
desc
¶ descriptor array
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volatile struct vring_avail *
avail
¶ the “avail” ring
-
volatile struct vring_used *
used
¶ the “used” ring
-
uint32_t
gpa_desc
[2]¶ gpa of descriptors
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uint32_t
gpa_avail
[2]¶ gpa of avail_ring
-
uint32_t
gpa_used
[2]¶ gpa of used_ring
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bool
enabled
¶ whether the virtqueue is enabled
-
uint16_t
-
struct
vhost_vq
¶ - #include <vhost.h>
-
struct
vhost_dev
¶ - #include <vhost.h>
Public Members
-
struct virtio_base *
base
¶ backpointer to virtio_base
-
int
nvqs
¶ number of virtqueues
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int
fd
¶ vhost chardev fd
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int
vq_idx
¶ first vq’s index in virtio_vq_info
-
uint64_t
vhost_features
¶ supported virtio defined features
-
uint64_t
vhost_ext_features
¶ vhost self-defined internal features bits used for communicate between vhost user-space and kernel-space modules
-
uint32_t
busyloop_timeout
¶ vq busyloop timeout in us
-
bool
started
¶ whether vhost is started
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struct virtio_base *
-