2c2
< * Copyright (c) 2011 NetApp, Inc.
---
> * Copyright (c) 2013 Chris Torek <torek @ torek net>
14c14
< * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
---
> * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17c17
< * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
---
> * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26c26
< * $FreeBSD: head/usr.sbin/bhyve/virtio.h 250197 2013-05-03 01:16:18Z neel $
---
> * $FreeBSD: head/usr.sbin/bhyve/virtio.h 253440 2013-07-17 23:37:33Z grehan $
31a32,121
> /*
> * These are derived from several virtio specifications.
> *
> * Some useful links:
> * https://github.com/rustyrussel/virtio-spec
> * http://people.redhat.com/pbonzini/virtio-spec.pdf
> */
>
> /*
> * A virtual device has zero or more "virtual queues" (virtqueue).
> * Each virtqueue uses at least two 4096-byte pages, laid out thus:
> *
> * +-----------------------------------------------+
> * | "desc": <N> descriptors, 16 bytes each |
> * | ----------------------------------------- |
> * | "avail": 2 uint16; <N> uint16; 1 uint16 |
> * | ----------------------------------------- |
> * | pad to 4k boundary |
> * +-----------------------------------------------+
> * | "used": 2 x uint16; <N> elems; 1 uint16 |
> * | ----------------------------------------- |
> * | pad to 4k boundary |
> * +-----------------------------------------------+
> *
> * The number <N> that appears here is always a power of two and is
> * limited to no more than 32768 (as it must fit in a 16-bit field).
> * If <N> is sufficiently large, the above will occupy more than
> * two pages. In any case, all pages must be physically contiguous
> * within the guest's physical address space.
> *
> * The <N> 16-byte "desc" descriptors consist of a 64-bit guest
> * physical address <addr>, a 32-bit length <len>, a 16-bit
> * <flags>, and a 16-bit <next> field (all in guest byte order).
> *
> * There are three flags that may be set :
> * NEXT descriptor is chained, so use its "next" field
> * WRITE descriptor is for host to write into guest RAM
> * (else host is to read from guest RAM)
> * INDIRECT descriptor address field is (guest physical)
> * address of a linear array of descriptors
> *
> * Unless INDIRECT is set, <len> is the number of bytes that may
> * be read/written from guest physical address <addr>. If
> * INDIRECT is set, WRITE is ignored and <len> provides the length
> * of the indirect descriptors (and <len> must be a multiple of
> * 16). Note that NEXT may still be set in the main descriptor
> * pointing to the indirect, and should be set in each indirect
> * descriptor that uses the next descriptor (these should generally
> * be numbered sequentially). However, INDIRECT must not be set
> * in the indirect descriptors. Upon reaching an indirect descriptor
> * without a NEXT bit, control returns to the direct descriptors.
> *
> * Except inside an indirect, each <next> value must be in the
> * range [0 .. N) (i.e., the half-open interval). (Inside an
> * indirect, each <next> must be in the range [0 .. <len>/16).)
> *
> * The "avail" data structures reside in the same pages as the
> * "desc" structures since both together are used by the device to
> * pass information to the hypervisor's virtual driver. These
> * begin with a 16-bit <flags> field and 16-bit index <idx>, then
> * have <N> 16-bit <ring> values, followed by one final 16-bit
> * field <used_event>. The <N> <ring> entries are simply indices
> * indices into the descriptor ring (and thus must meet the same
> * constraints as each <next> value). However, <idx> is counted
> * up from 0 (initially) and simply wraps around after 65535; it
> * is taken mod <N> to find the next available entry.
> *
> * The "used" ring occupies a separate page or pages, and contains
> * values written from the virtual driver back to the guest OS.
> * This begins with a 16-bit <flags> and 16-bit <idx>, then there
> * are <N> "vring_used" elements, followed by a 16-bit <avail_event>.
> * The <N> "vring_used" elements consist of a 32-bit <id> and a
> * 32-bit <len> (vu_tlen below). The <id> is simply the index of
> * the head of a descriptor chain the guest made available
> * earlier, and the <len> is the number of bytes actually written,
> * e.g., in the case of a network driver that provided a large
> * receive buffer but received only a small amount of data.
> *
> * The two event fields, <used_event> and <avail_event>, in the
> * avail and used rings (respectively -- note the reversal!), are
> * always provided, but are used only if the virtual device
> * negotiates the VIRTIO_RING_F_EVENT_IDX feature during feature
> * negotiation. Similarly, both rings provide a flag --
> * VRING_AVAIL_F_NO_INTERRUPT and VRING_USED_F_NO_NOTIFY -- in
> * their <flags> field, indicating that the guest does not need an
> * interrupt, or that the hypervisor driver does not need a
> * notify, when descriptors are added to the corresponding ring.
> * (These are provided only for interrupt optimization and need
> * not be implemented.)
> */
37a128,139
> struct virtio_desc { /* AKA vring_desc */
> uint64_t vd_addr; /* guest physical address */
> uint32_t vd_len; /* length of scatter/gather seg */
> uint16_t vd_flags; /* VRING_F_DESC_* */
> uint16_t vd_next; /* next desc if F_NEXT */
> } __packed;
>
> struct virtio_used { /* AKA vring_used_elem */
> uint32_t vu_idx; /* head of used descriptor chain */
> uint32_t vu_tlen; /* length written-to */
> } __packed;
>
39d140
< #define VIRTIO_MSI_NO_VECTOR 0xFFFF
41,45c142,146
< struct virtio_desc {
< uint64_t vd_addr;
< uint32_t vd_len;
< uint16_t vd_flags;
< uint16_t vd_next;
---
> struct vring_avail {
> uint16_t va_flags; /* VRING_AVAIL_F_* */
> uint16_t va_idx; /* counts to 65535, then cycles */
> uint16_t va_ring[]; /* size N, reported in QNUM value */
> /* uint16_t va_used_event; -- after N ring entries */
48,50c149,154
< struct virtio_used {
< uint32_t vu_idx;
< uint32_t vu_tlen;
---
> #define VRING_USED_F_NO_NOTIFY 1
> struct vring_used {
> uint16_t vu_flags; /* VRING_USED_F_* */
> uint16_t vu_idx; /* counts to 65535, then cycles */
> struct virtio_used vu_ring[]; /* size N */
> /* uint16_t vu_avail_event; -- after N ring entries */
53a158,184
> * The address of any given virtual queue is determined by a single
> * Page Frame Number register. The guest writes the PFN into the
> * PCI config space. However, a device that has two or more
> * virtqueues can have a different PFN, and size, for each queue.
> * The number of queues is determinable via the PCI config space
> * VTCFG_R_QSEL register. Writes to QSEL select the queue: 0 means
> * queue #0, 1 means queue#1, etc. Once a queue is selected, the
> * remaining PFN and QNUM registers refer to that queue.
> *
> * QNUM is a read-only register containing a nonzero power of two
> * that indicates the (hypervisor's) queue size. Or, if reading it
> * produces zero, the hypervisor does not have a corresponding
> * queue. (The number of possible queues depends on the virtual
> * device. The block device has just one; the network device
> * provides either two -- 0 = receive, 1 = transmit -- or three,
> * with 2 = control.)
> *
> * PFN is a read/write register giving the physical page address of
> * the virtqueue in guest memory (the guest must allocate enough space
> * based on the hypervisor's provided QNUM).
> *
> * QNOTIFY is effectively write-only: when the guest writes a queue
> * number to the register, the hypervisor should scan the specified
> * virtqueue. (Reading QNOTIFY currently always gets 0).
> */
>
> /*
56c187
< #define VRING_PFN 12
---
> #define VRING_PFN 12
59a191,192
> *
> * XXX Should really be merged with <dev/virtio/virtio.h> defines
61,62c194,202
< #define VIRTIO_TYPE_NET 1
< #define VIRTIO_TYPE_BLOCK 2
---
> #define VIRTIO_TYPE_NET 1
> #define VIRTIO_TYPE_BLOCK 2
> #define VIRTIO_TYPE_CONSOLE 3
> #define VIRTIO_TYPE_ENTROPY 4
> #define VIRTIO_TYPE_BALLOON 5
> #define VIRTIO_TYPE_IOMEMORY 6
> #define VIRTIO_TYPE_RPMSG 7
> #define VIRTIO_TYPE_SCSI 8
> #define VIRTIO_TYPE_9P 9
63a204,205
> /* experimental IDs start at 65535 and work down */
>
67,69c209,211
< #define VIRTIO_VENDOR 0x1AF4
< #define VIRTIO_DEV_NET 0x1000
< #define VIRTIO_DEV_BLOCK 0x1001
---
> #define VIRTIO_VENDOR 0x1AF4
> #define VIRTIO_DEV_NET 0x1000
> #define VIRTIO_DEV_BLOCK 0x1001
72c214,220
< * PCI config space constants
---
> * PCI config space constants.
> *
> * If MSI-X is enabled, the ISR register is generally not used,
> * and the configuration vector and queue vector appear at offsets
> * 20 and 22 with the remaining configuration registers at 24.
> * If MSI-X is not enabled, those two registers disappear and
> * the remaining configuration registers start at offset 20.
88c236,258
< /* Feature flags */
---
> /*
> * Bits in VTCFG_R_STATUS. Guests need not actually set any of these,
> * but a guest writing 0 to this register means "please reset".
> */
> #define VTCFG_STATUS_ACK 0x01 /* guest OS has acknowledged dev */
> #define VTCFG_STATUS_DRIVER 0x02 /* guest OS driver is loaded */
> #define VTCFG_STATUS_DRIVER_OK 0x04 /* guest OS driver ready */
> #define VTCFG_STATUS_FAILED 0x80 /* guest has given up on this dev */
>
> /*
> * Bits in VTCFG_R_ISR. These apply only if not using MSI-X.
> *
> * (We don't [yet?] ever use CONF_CHANGED.)
> */
> #define VTCFG_ISR_QUEUES 0x01 /* re-scan queues */
> #define VTCFG_ISR_CONF_CHANGED 0x80 /* configuration changed */
>
> #define VIRTIO_MSI_NO_VECTOR 0xFFFF
>
> /*
> * Feature flags.
> * Note: bits 0 through 23 are reserved to each device type.
> */
89a260,261
> #define VIRTIO_RING_F_INDIRECT_DESC (1 << 28)
> #define VIRTIO_RING_F_EVENT_IDX (1 << 29)
92c264
< static inline u_int
---
> static inline size_t
95c267
< u_int size;
---
> size_t size;
96a269
> /* constant 3 below = va_flags, va_idx, va_used_event */
99a273
> /* constant 3 below = vu_flags, vu_idx, vu_avail_event */
105a280,458
> struct vmctx;
> struct pci_devinst;
> struct vqueue_info;
>
> /*
> * A virtual device, with some number (possibly 0) of virtual
> * queues and some size (possibly 0) of configuration-space
> * registers private to the device. The virtio_softc should come
> * at the front of each "derived class", so that a pointer to the
> * virtio_softc is also a pointer to the more specific, derived-
> * from-virtio driver's softc.
> *
> * Note: inside each hypervisor virtio driver, changes to these
> * data structures must be locked against other threads, if any.
> * Except for PCI config space register read/write, we assume each
> * driver does the required locking, but we need a pointer to the
> * lock (if there is one) for PCI config space read/write ops.
> *
> * When the guest reads or writes the device's config space, the
> * generic layer checks for operations on the special registers
> * described above. If the offset of the register(s) being read
> * or written is past the CFG area (CFG0 or CFG1), the request is
> * passed on to the virtual device, after subtracting off the
> * generic-layer size. (So, drivers can just use the offset as
> * an offset into "struct config", for instance.)
> *
> * (The virtio layer also makes sure that the read or write is to/
> * from a "good" config offset, hence vc_cfgsize, and on BAR #0.
> * However, the driver must verify the read or write size and offset
> * and that no one is writing a readonly register.)
> *
> * The BROKED flag ("this thing done gone and broked") is for future
> * use.
> */
> #define VIRTIO_USE_MSIX 0x01
> #define VIRTIO_EVENT_IDX 0x02 /* use the event-index values */
> #define VIRTIO_BROKED 0x08 /* ??? */
>
> struct virtio_softc {
> struct virtio_consts *vs_vc; /* constants (see below) */
> int vs_flags; /* VIRTIO_* flags from above */
> pthread_mutex_t *vs_mtx; /* POSIX mutex, if any */
> struct pci_devinst *vs_pi; /* PCI device instance */
> uint32_t vs_negotiated_caps; /* negotiated capabilities */
> struct vqueue_info *vs_queues; /* one per vc_nvq */
> int vs_curq; /* current queue */
> uint8_t vs_status; /* value from last status write */
> uint8_t vs_isr; /* ISR flags, if not MSI-X */
> uint16_t vs_msix_cfg_idx; /* MSI-X vector for config event */
> };
>
> struct virtio_consts {
> const char *vc_name; /* name of driver (for diagnostics) */
> int vc_nvq; /* number of virtual queues */
> size_t vc_cfgsize; /* size of dev-specific config regs */
> void (*vc_reset)(void *); /* called on virtual device reset */
> void (*vc_qnotify)(void *, struct vqueue_info *);
> /* called on QNOTIFY if no VQ notify */
> int (*vc_cfgread)(void *, int, int, uint32_t *);
> /* called to read config regs */
> int (*vc_cfgwrite)(void *, int, int, uint32_t);
> /* called to write config regs */
> uint32_t vc_hv_caps; /* hypervisor-provided capabilities */
> };
>
> /*
> * Data structure allocated (statically) per virtual queue.
> *
> * Drivers may change vq_qsize after a reset. When the guest OS
> * requests a device reset, the hypervisor first calls
> * vs->vs_vc->vc_reset(); then the data structure below is
> * reinitialized (for each virtqueue: vs->vs_vc->vc_nvq).
> *
> * The remaining fields should only be fussed-with by the generic
> * code.
> *
> * Note: the addresses of vq_desc, vq_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].
> */
> #define VQ_ALLOC 0x01 /* set once we have a pfn */
> #define VQ_BROKED 0x02 /* ??? */
> struct vqueue_info {
> uint16_t vq_qsize; /* size of this queue (a power of 2) */
> void (*vq_notify)(void *, struct vqueue_info *);
> /* called instead of vc_notify, if not NULL */
>
> struct virtio_softc *vq_vs; /* backpointer to softc */
> uint16_t vq_num; /* we're the num'th queue in the softc */
>
> uint16_t vq_flags; /* flags (see above) */
> uint16_t vq_last_avail; /* a recent value of vq_avail->va_idx */
> uint16_t vq_save_used; /* saved vq_used->vu_idx; see vq_endchains */
> uint16_t vq_msix_idx; /* MSI-X index, or VIRTIO_MSI_NO_VECTOR */
>
> uint32_t vq_pfn; /* PFN of virt queue (not shifted!) */
>
> volatile struct virtio_desc *vq_desc; /* descriptor array */
> volatile struct vring_avail *vq_avail; /* the "avail" ring */
> volatile struct vring_used *vq_used; /* the "used" ring */
>
> };
> /* as noted above, these are sort of backwards, name-wise */
> #define VQ_AVAIL_EVENT_IDX(vq) \
> (*(volatile uint16_t *)&(vq)->vq_used->vu_ring[(vq)->vq_qsize])
> #define VQ_USED_EVENT_IDX(vq) \
> ((vq)->vq_avail->va_ring[(vq)->vq_qsize])
>
> /*
> * Is this ring ready for I/O?
> */
> static inline int
> vq_ring_ready(struct vqueue_info *vq)
> {
>
> return (vq->vq_flags & VQ_ALLOC);
> }
>
> /*
> * Are there "available" descriptors? (This does not count
> * how many, just returns True if there are some.)
> */
> static inline int
> vq_has_descs(struct vqueue_info *vq)
> {
>
> return (vq_ring_ready(vq) && vq->vq_last_avail !=
> vq->vq_avail->va_idx);
> }
>
> /*
> * Called by virtio driver as it starts processing chains. Each
> * completed chain (obtained from vq_getchain()) is released by
> * calling vq_relchain(), then when all are done, vq_endchains()
> * can tell if / how-many chains were processed and know whether
> * and how to generate an interrupt.
> */
> static inline void
> vq_startchains(struct vqueue_info *vq)
> {
>
> vq->vq_save_used = vq->vq_used->vu_idx;
> }
>
> /*
> * Deliver an interrupt to guest on the given virtual queue
> * (if possible, or a generic MSI interrupt if not using MSI-X).
> */
> static inline void
> vq_interrupt(struct virtio_softc *vs, struct vqueue_info *vq)
> {
>
> if (vs->vs_flags & VIRTIO_USE_MSIX)
> pci_generate_msix(vs->vs_pi, vq->vq_msix_idx);
> else {
> vs->vs_isr |= VTCFG_ISR_QUEUES;
> pci_generate_msi(vs->vs_pi, 0);
> }
> }
>
> struct iovec;
> void vi_softc_linkup(struct virtio_softc *vs, struct virtio_consts *vc,
> void *dev_softc, struct pci_devinst *pi,
> struct vqueue_info *queues);
> int vi_intr_init(struct virtio_softc *vs, int barnum, int use_msix);
> void vi_reset_dev(struct virtio_softc *);
> void vi_set_io_bar(struct virtio_softc *, int);
>
> int vq_getchain(struct vqueue_info *vq,
> struct iovec *iov, int n_iov, uint16_t *flags);
> void vq_relchain(struct vqueue_info *vq, uint32_t iolen);
> void vq_endchains(struct vqueue_info *vq, int used_all_avail);
>
> uint64_t vi_pci_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
> int baridx, uint64_t offset, int size);
> void vi_pci_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
> int baridx, uint64_t offset, int size, uint64_t value);
< * Copyright (c) 2011 NetApp, Inc.
---
> * Copyright (c) 2013 Chris Torek <torek @ torek net>
14c14
< * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
---
> * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17c17
< * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
---
> * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26c26
< * $FreeBSD: head/usr.sbin/bhyve/virtio.h 250197 2013-05-03 01:16:18Z neel $
---
> * $FreeBSD: head/usr.sbin/bhyve/virtio.h 253440 2013-07-17 23:37:33Z grehan $
31a32,121
> /*
> * These are derived from several virtio specifications.
> *
> * Some useful links:
> * https://github.com/rustyrussel/virtio-spec
> * http://people.redhat.com/pbonzini/virtio-spec.pdf
> */
>
> /*
> * A virtual device has zero or more "virtual queues" (virtqueue).
> * Each virtqueue uses at least two 4096-byte pages, laid out thus:
> *
> * +-----------------------------------------------+
> * | "desc": <N> descriptors, 16 bytes each |
> * | ----------------------------------------- |
> * | "avail": 2 uint16; <N> uint16; 1 uint16 |
> * | ----------------------------------------- |
> * | pad to 4k boundary |
> * +-----------------------------------------------+
> * | "used": 2 x uint16; <N> elems; 1 uint16 |
> * | ----------------------------------------- |
> * | pad to 4k boundary |
> * +-----------------------------------------------+
> *
> * The number <N> that appears here is always a power of two and is
> * limited to no more than 32768 (as it must fit in a 16-bit field).
> * If <N> is sufficiently large, the above will occupy more than
> * two pages. In any case, all pages must be physically contiguous
> * within the guest's physical address space.
> *
> * The <N> 16-byte "desc" descriptors consist of a 64-bit guest
> * physical address <addr>, a 32-bit length <len>, a 16-bit
> * <flags>, and a 16-bit <next> field (all in guest byte order).
> *
> * There are three flags that may be set :
> * NEXT descriptor is chained, so use its "next" field
> * WRITE descriptor is for host to write into guest RAM
> * (else host is to read from guest RAM)
> * INDIRECT descriptor address field is (guest physical)
> * address of a linear array of descriptors
> *
> * Unless INDIRECT is set, <len> is the number of bytes that may
> * be read/written from guest physical address <addr>. If
> * INDIRECT is set, WRITE is ignored and <len> provides the length
> * of the indirect descriptors (and <len> must be a multiple of
> * 16). Note that NEXT may still be set in the main descriptor
> * pointing to the indirect, and should be set in each indirect
> * descriptor that uses the next descriptor (these should generally
> * be numbered sequentially). However, INDIRECT must not be set
> * in the indirect descriptors. Upon reaching an indirect descriptor
> * without a NEXT bit, control returns to the direct descriptors.
> *
> * Except inside an indirect, each <next> value must be in the
> * range [0 .. N) (i.e., the half-open interval). (Inside an
> * indirect, each <next> must be in the range [0 .. <len>/16).)
> *
> * The "avail" data structures reside in the same pages as the
> * "desc" structures since both together are used by the device to
> * pass information to the hypervisor's virtual driver. These
> * begin with a 16-bit <flags> field and 16-bit index <idx>, then
> * have <N> 16-bit <ring> values, followed by one final 16-bit
> * field <used_event>. The <N> <ring> entries are simply indices
> * indices into the descriptor ring (and thus must meet the same
> * constraints as each <next> value). However, <idx> is counted
> * up from 0 (initially) and simply wraps around after 65535; it
> * is taken mod <N> to find the next available entry.
> *
> * The "used" ring occupies a separate page or pages, and contains
> * values written from the virtual driver back to the guest OS.
> * This begins with a 16-bit <flags> and 16-bit <idx>, then there
> * are <N> "vring_used" elements, followed by a 16-bit <avail_event>.
> * The <N> "vring_used" elements consist of a 32-bit <id> and a
> * 32-bit <len> (vu_tlen below). The <id> is simply the index of
> * the head of a descriptor chain the guest made available
> * earlier, and the <len> is the number of bytes actually written,
> * e.g., in the case of a network driver that provided a large
> * receive buffer but received only a small amount of data.
> *
> * The two event fields, <used_event> and <avail_event>, in the
> * avail and used rings (respectively -- note the reversal!), are
> * always provided, but are used only if the virtual device
> * negotiates the VIRTIO_RING_F_EVENT_IDX feature during feature
> * negotiation. Similarly, both rings provide a flag --
> * VRING_AVAIL_F_NO_INTERRUPT and VRING_USED_F_NO_NOTIFY -- in
> * their <flags> field, indicating that the guest does not need an
> * interrupt, or that the hypervisor driver does not need a
> * notify, when descriptors are added to the corresponding ring.
> * (These are provided only for interrupt optimization and need
> * not be implemented.)
> */
37a128,139
> struct virtio_desc { /* AKA vring_desc */
> uint64_t vd_addr; /* guest physical address */
> uint32_t vd_len; /* length of scatter/gather seg */
> uint16_t vd_flags; /* VRING_F_DESC_* */
> uint16_t vd_next; /* next desc if F_NEXT */
> } __packed;
>
> struct virtio_used { /* AKA vring_used_elem */
> uint32_t vu_idx; /* head of used descriptor chain */
> uint32_t vu_tlen; /* length written-to */
> } __packed;
>
39d140
< #define VIRTIO_MSI_NO_VECTOR 0xFFFF
41,45c142,146
< struct virtio_desc {
< uint64_t vd_addr;
< uint32_t vd_len;
< uint16_t vd_flags;
< uint16_t vd_next;
---
> struct vring_avail {
> uint16_t va_flags; /* VRING_AVAIL_F_* */
> uint16_t va_idx; /* counts to 65535, then cycles */
> uint16_t va_ring[]; /* size N, reported in QNUM value */
> /* uint16_t va_used_event; -- after N ring entries */
48,50c149,154
< struct virtio_used {
< uint32_t vu_idx;
< uint32_t vu_tlen;
---
> #define VRING_USED_F_NO_NOTIFY 1
> struct vring_used {
> uint16_t vu_flags; /* VRING_USED_F_* */
> uint16_t vu_idx; /* counts to 65535, then cycles */
> struct virtio_used vu_ring[]; /* size N */
> /* uint16_t vu_avail_event; -- after N ring entries */
53a158,184
> * The address of any given virtual queue is determined by a single
> * Page Frame Number register. The guest writes the PFN into the
> * PCI config space. However, a device that has two or more
> * virtqueues can have a different PFN, and size, for each queue.
> * The number of queues is determinable via the PCI config space
> * VTCFG_R_QSEL register. Writes to QSEL select the queue: 0 means
> * queue #0, 1 means queue#1, etc. Once a queue is selected, the
> * remaining PFN and QNUM registers refer to that queue.
> *
> * QNUM is a read-only register containing a nonzero power of two
> * that indicates the (hypervisor's) queue size. Or, if reading it
> * produces zero, the hypervisor does not have a corresponding
> * queue. (The number of possible queues depends on the virtual
> * device. The block device has just one; the network device
> * provides either two -- 0 = receive, 1 = transmit -- or three,
> * with 2 = control.)
> *
> * PFN is a read/write register giving the physical page address of
> * the virtqueue in guest memory (the guest must allocate enough space
> * based on the hypervisor's provided QNUM).
> *
> * QNOTIFY is effectively write-only: when the guest writes a queue
> * number to the register, the hypervisor should scan the specified
> * virtqueue. (Reading QNOTIFY currently always gets 0).
> */
>
> /*
56c187
< #define VRING_PFN 12
---
> #define VRING_PFN 12
59a191,192
> *
> * XXX Should really be merged with <dev/virtio/virtio.h> defines
61,62c194,202
< #define VIRTIO_TYPE_NET 1
< #define VIRTIO_TYPE_BLOCK 2
---
> #define VIRTIO_TYPE_NET 1
> #define VIRTIO_TYPE_BLOCK 2
> #define VIRTIO_TYPE_CONSOLE 3
> #define VIRTIO_TYPE_ENTROPY 4
> #define VIRTIO_TYPE_BALLOON 5
> #define VIRTIO_TYPE_IOMEMORY 6
> #define VIRTIO_TYPE_RPMSG 7
> #define VIRTIO_TYPE_SCSI 8
> #define VIRTIO_TYPE_9P 9
63a204,205
> /* experimental IDs start at 65535 and work down */
>
67,69c209,211
< #define VIRTIO_VENDOR 0x1AF4
< #define VIRTIO_DEV_NET 0x1000
< #define VIRTIO_DEV_BLOCK 0x1001
---
> #define VIRTIO_VENDOR 0x1AF4
> #define VIRTIO_DEV_NET 0x1000
> #define VIRTIO_DEV_BLOCK 0x1001
72c214,220
< * PCI config space constants
---
> * PCI config space constants.
> *
> * If MSI-X is enabled, the ISR register is generally not used,
> * and the configuration vector and queue vector appear at offsets
> * 20 and 22 with the remaining configuration registers at 24.
> * If MSI-X is not enabled, those two registers disappear and
> * the remaining configuration registers start at offset 20.
88c236,258
< /* Feature flags */
---
> /*
> * Bits in VTCFG_R_STATUS. Guests need not actually set any of these,
> * but a guest writing 0 to this register means "please reset".
> */
> #define VTCFG_STATUS_ACK 0x01 /* guest OS has acknowledged dev */
> #define VTCFG_STATUS_DRIVER 0x02 /* guest OS driver is loaded */
> #define VTCFG_STATUS_DRIVER_OK 0x04 /* guest OS driver ready */
> #define VTCFG_STATUS_FAILED 0x80 /* guest has given up on this dev */
>
> /*
> * Bits in VTCFG_R_ISR. These apply only if not using MSI-X.
> *
> * (We don't [yet?] ever use CONF_CHANGED.)
> */
> #define VTCFG_ISR_QUEUES 0x01 /* re-scan queues */
> #define VTCFG_ISR_CONF_CHANGED 0x80 /* configuration changed */
>
> #define VIRTIO_MSI_NO_VECTOR 0xFFFF
>
> /*
> * Feature flags.
> * Note: bits 0 through 23 are reserved to each device type.
> */
89a260,261
> #define VIRTIO_RING_F_INDIRECT_DESC (1 << 28)
> #define VIRTIO_RING_F_EVENT_IDX (1 << 29)
92c264
< static inline u_int
---
> static inline size_t
95c267
< u_int size;
---
> size_t size;
96a269
> /* constant 3 below = va_flags, va_idx, va_used_event */
99a273
> /* constant 3 below = vu_flags, vu_idx, vu_avail_event */
105a280,458
> struct vmctx;
> struct pci_devinst;
> struct vqueue_info;
>
> /*
> * A virtual device, with some number (possibly 0) of virtual
> * queues and some size (possibly 0) of configuration-space
> * registers private to the device. The virtio_softc should come
> * at the front of each "derived class", so that a pointer to the
> * virtio_softc is also a pointer to the more specific, derived-
> * from-virtio driver's softc.
> *
> * Note: inside each hypervisor virtio driver, changes to these
> * data structures must be locked against other threads, if any.
> * Except for PCI config space register read/write, we assume each
> * driver does the required locking, but we need a pointer to the
> * lock (if there is one) for PCI config space read/write ops.
> *
> * When the guest reads or writes the device's config space, the
> * generic layer checks for operations on the special registers
> * described above. If the offset of the register(s) being read
> * or written is past the CFG area (CFG0 or CFG1), the request is
> * passed on to the virtual device, after subtracting off the
> * generic-layer size. (So, drivers can just use the offset as
> * an offset into "struct config", for instance.)
> *
> * (The virtio layer also makes sure that the read or write is to/
> * from a "good" config offset, hence vc_cfgsize, and on BAR #0.
> * However, the driver must verify the read or write size and offset
> * and that no one is writing a readonly register.)
> *
> * The BROKED flag ("this thing done gone and broked") is for future
> * use.
> */
> #define VIRTIO_USE_MSIX 0x01
> #define VIRTIO_EVENT_IDX 0x02 /* use the event-index values */
> #define VIRTIO_BROKED 0x08 /* ??? */
>
> struct virtio_softc {
> struct virtio_consts *vs_vc; /* constants (see below) */
> int vs_flags; /* VIRTIO_* flags from above */
> pthread_mutex_t *vs_mtx; /* POSIX mutex, if any */
> struct pci_devinst *vs_pi; /* PCI device instance */
> uint32_t vs_negotiated_caps; /* negotiated capabilities */
> struct vqueue_info *vs_queues; /* one per vc_nvq */
> int vs_curq; /* current queue */
> uint8_t vs_status; /* value from last status write */
> uint8_t vs_isr; /* ISR flags, if not MSI-X */
> uint16_t vs_msix_cfg_idx; /* MSI-X vector for config event */
> };
>
> struct virtio_consts {
> const char *vc_name; /* name of driver (for diagnostics) */
> int vc_nvq; /* number of virtual queues */
> size_t vc_cfgsize; /* size of dev-specific config regs */
> void (*vc_reset)(void *); /* called on virtual device reset */
> void (*vc_qnotify)(void *, struct vqueue_info *);
> /* called on QNOTIFY if no VQ notify */
> int (*vc_cfgread)(void *, int, int, uint32_t *);
> /* called to read config regs */
> int (*vc_cfgwrite)(void *, int, int, uint32_t);
> /* called to write config regs */
> uint32_t vc_hv_caps; /* hypervisor-provided capabilities */
> };
>
> /*
> * Data structure allocated (statically) per virtual queue.
> *
> * Drivers may change vq_qsize after a reset. When the guest OS
> * requests a device reset, the hypervisor first calls
> * vs->vs_vc->vc_reset(); then the data structure below is
> * reinitialized (for each virtqueue: vs->vs_vc->vc_nvq).
> *
> * The remaining fields should only be fussed-with by the generic
> * code.
> *
> * Note: the addresses of vq_desc, vq_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].
> */
> #define VQ_ALLOC 0x01 /* set once we have a pfn */
> #define VQ_BROKED 0x02 /* ??? */
> struct vqueue_info {
> uint16_t vq_qsize; /* size of this queue (a power of 2) */
> void (*vq_notify)(void *, struct vqueue_info *);
> /* called instead of vc_notify, if not NULL */
>
> struct virtio_softc *vq_vs; /* backpointer to softc */
> uint16_t vq_num; /* we're the num'th queue in the softc */
>
> uint16_t vq_flags; /* flags (see above) */
> uint16_t vq_last_avail; /* a recent value of vq_avail->va_idx */
> uint16_t vq_save_used; /* saved vq_used->vu_idx; see vq_endchains */
> uint16_t vq_msix_idx; /* MSI-X index, or VIRTIO_MSI_NO_VECTOR */
>
> uint32_t vq_pfn; /* PFN of virt queue (not shifted!) */
>
> volatile struct virtio_desc *vq_desc; /* descriptor array */
> volatile struct vring_avail *vq_avail; /* the "avail" ring */
> volatile struct vring_used *vq_used; /* the "used" ring */
>
> };
> /* as noted above, these are sort of backwards, name-wise */
> #define VQ_AVAIL_EVENT_IDX(vq) \
> (*(volatile uint16_t *)&(vq)->vq_used->vu_ring[(vq)->vq_qsize])
> #define VQ_USED_EVENT_IDX(vq) \
> ((vq)->vq_avail->va_ring[(vq)->vq_qsize])
>
> /*
> * Is this ring ready for I/O?
> */
> static inline int
> vq_ring_ready(struct vqueue_info *vq)
> {
>
> return (vq->vq_flags & VQ_ALLOC);
> }
>
> /*
> * Are there "available" descriptors? (This does not count
> * how many, just returns True if there are some.)
> */
> static inline int
> vq_has_descs(struct vqueue_info *vq)
> {
>
> return (vq_ring_ready(vq) && vq->vq_last_avail !=
> vq->vq_avail->va_idx);
> }
>
> /*
> * Called by virtio driver as it starts processing chains. Each
> * completed chain (obtained from vq_getchain()) is released by
> * calling vq_relchain(), then when all are done, vq_endchains()
> * can tell if / how-many chains were processed and know whether
> * and how to generate an interrupt.
> */
> static inline void
> vq_startchains(struct vqueue_info *vq)
> {
>
> vq->vq_save_used = vq->vq_used->vu_idx;
> }
>
> /*
> * Deliver an interrupt to guest on the given virtual queue
> * (if possible, or a generic MSI interrupt if not using MSI-X).
> */
> static inline void
> vq_interrupt(struct virtio_softc *vs, struct vqueue_info *vq)
> {
>
> if (vs->vs_flags & VIRTIO_USE_MSIX)
> pci_generate_msix(vs->vs_pi, vq->vq_msix_idx);
> else {
> vs->vs_isr |= VTCFG_ISR_QUEUES;
> pci_generate_msi(vs->vs_pi, 0);
> }
> }
>
> struct iovec;
> void vi_softc_linkup(struct virtio_softc *vs, struct virtio_consts *vc,
> void *dev_softc, struct pci_devinst *pi,
> struct vqueue_info *queues);
> int vi_intr_init(struct virtio_softc *vs, int barnum, int use_msix);
> void vi_reset_dev(struct virtio_softc *);
> void vi_set_io_bar(struct virtio_softc *, int);
>
> int vq_getchain(struct vqueue_info *vq,
> struct iovec *iov, int n_iov, uint16_t *flags);
> void vq_relchain(struct vqueue_info *vq, uint32_t iolen);
> void vq_endchains(struct vqueue_info *vq, int used_all_avail);
>
> uint64_t vi_pci_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
> int baridx, uint64_t offset, int size);
> void vi_pci_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
> int baridx, uint64_t offset, int size, uint64_t value);