diff options
Diffstat (limited to 'hw/hyperv')
| -rw-r--r-- | hw/hyperv/Kconfig | 5 | ||||
| -rw-r--r-- | hw/hyperv/Makefile.objs | 1 | ||||
| -rw-r--r-- | hw/hyperv/trace-events | 18 | ||||
| -rw-r--r-- | hw/hyperv/vmbus.c | 2672 |
4 files changed, 2696 insertions, 0 deletions
diff --git a/hw/hyperv/Kconfig b/hw/hyperv/Kconfig index a1fa8ff9be..3fbfe41c9e 100644 --- a/hw/hyperv/Kconfig +++ b/hw/hyperv/Kconfig @@ -6,3 +6,8 @@ config HYPERV_TESTDEV bool default y if TEST_DEVICES depends on HYPERV + +config VMBUS + bool + default y + depends on HYPERV diff --git a/hw/hyperv/Makefile.objs b/hw/hyperv/Makefile.objs index edaca2f763..5b614e040c 100644 --- a/hw/hyperv/Makefile.objs +++ b/hw/hyperv/Makefile.objs @@ -1,2 +1,3 @@ obj-y += hyperv.o obj-$(CONFIG_HYPERV_TESTDEV) += hyperv_testdev.o +obj-$(CONFIG_VMBUS) += vmbus.o diff --git a/hw/hyperv/trace-events b/hw/hyperv/trace-events new file mode 100644 index 0000000000..ba5bd62d61 --- /dev/null +++ b/hw/hyperv/trace-events @@ -0,0 +1,18 @@ +# vmbus +vmbus_recv_message(uint32_t type, uint32_t size) "type %d size %d" +vmbus_signal_event(void) "" +vmbus_channel_notify_guest(uint32_t chan_id) "channel #%d" +vmbus_post_msg(uint32_t type, uint32_t size) "type %d size %d" +vmbus_msg_cb(int status) "message status %d" +vmbus_process_incoming_message(uint32_t message_type) "type %d" +vmbus_initiate_contact(uint16_t major, uint16_t minor, uint32_t vcpu, uint64_t monitor_page1, uint64_t monitor_page2, uint64_t interrupt_page) "version %d.%d target vp %d mon pages 0x%"PRIx64",0x%"PRIx64" int page 0x%"PRIx64 +vmbus_send_offer(uint32_t chan_id, void *dev) "channel #%d dev %p" +vmbus_terminate_offers(void) "" +vmbus_gpadl_header(uint32_t gpadl_id, uint16_t num_gfns) "gpadl #%d gfns %d" +vmbus_gpadl_body(uint32_t gpadl_id) "gpadl #%d" +vmbus_gpadl_created(uint32_t gpadl_id) "gpadl #%d" +vmbus_gpadl_teardown(uint32_t gpadl_id) "gpadl #%d" +vmbus_gpadl_torndown(uint32_t gpadl_id) "gpadl #%d" +vmbus_open_channel(uint32_t chan_id, uint32_t gpadl_id, uint32_t target_vp) "channel #%d gpadl #%d target vp %d" +vmbus_channel_open(uint32_t chan_id, uint32_t status) "channel #%d status %d" +vmbus_close_channel(uint32_t chan_id) "channel #%d" diff --git a/hw/hyperv/vmbus.c b/hw/hyperv/vmbus.c new file mode 100644 index 0000000000..802bbc8c96 --- /dev/null +++ b/hw/hyperv/vmbus.c @@ -0,0 +1,2672 @@ +/* + * QEMU Hyper-V VMBus + * + * Copyright (c) 2017-2018 Virtuozzo International GmbH. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "qemu/main-loop.h" +#include "qapi/error.h" +#include "migration/vmstate.h" +#include "hw/qdev-properties.h" +#include "hw/hyperv/hyperv.h" +#include "hw/hyperv/vmbus.h" +#include "hw/hyperv/vmbus-bridge.h" +#include "hw/sysbus.h" +#include "cpu.h" +#include "trace.h" + +#define TYPE_VMBUS "vmbus" +#define VMBUS(obj) OBJECT_CHECK(VMBus, (obj), TYPE_VMBUS) + +enum { + VMGPADL_INIT, + VMGPADL_ALIVE, + VMGPADL_TEARINGDOWN, + VMGPADL_TORNDOWN, +}; + +struct VMBusGpadl { + /* GPADL id */ + uint32_t id; + /* associated channel id (rudimentary?) */ + uint32_t child_relid; + + /* number of pages in the GPADL as declared in GPADL_HEADER message */ + uint32_t num_gfns; + /* + * Due to limited message size, GPADL may not fit fully in a single + * GPADL_HEADER message, and is further popluated using GPADL_BODY + * messages. @seen_gfns is the number of pages seen so far; once it + * reaches @num_gfns, the GPADL is ready to use. + */ + uint32_t seen_gfns; + /* array of GFNs (of size @num_gfns once allocated) */ + uint64_t *gfns; + + uint8_t state; + + QTAILQ_ENTRY(VMBusGpadl) link; + VMBus *vmbus; + unsigned refcount; +}; + +/* + * Wrap sequential read from / write to GPADL. + */ +typedef struct GpadlIter { + VMBusGpadl *gpadl; + AddressSpace *as; + DMADirection dir; + /* offset into GPADL where the next i/o will be performed */ + uint32_t off; + /* + * Cached mapping of the currently accessed page, up to page boundary. + * Updated lazily on i/o. + * Note: MemoryRegionCache can not be used here because pages in the GPADL + * are non-contiguous and may belong to different memory regions. + */ + void *map; + /* offset after last i/o (i.e. not affected by seek) */ + uint32_t last_off; + /* + * Indicator that the iterator is active and may have a cached mapping. + * Allows to enforce bracketing of all i/o (which may create cached + * mappings) and thus exclude mapping leaks. + */ + bool active; +} GpadlIter; + +/* + * Ring buffer. There are two of them, sitting in the same GPADL, for each + * channel. + * Each ring buffer consists of a set of pages, with the first page containing + * the ring buffer header, and the remaining pages being for data packets. + */ +typedef struct VMBusRingBufCommon { + AddressSpace *as; + /* GPA of the ring buffer header */ + dma_addr_t rb_addr; + /* start and length of the ring buffer data area within GPADL */ + uint32_t base; + uint32_t len; + + GpadlIter iter; +} VMBusRingBufCommon; + +typedef struct VMBusSendRingBuf { + VMBusRingBufCommon common; + /* current write index, to be committed at the end of send */ + uint32_t wr_idx; + /* write index at the start of send */ + uint32_t last_wr_idx; + /* space to be requested from the guest */ + uint32_t wanted; + /* space reserved for planned sends */ + uint32_t reserved; + /* last seen read index */ + uint32_t last_seen_rd_idx; +} VMBusSendRingBuf; + +typedef struct VMBusRecvRingBuf { + VMBusRingBufCommon common; + /* current read index, to be committed at the end of receive */ + uint32_t rd_idx; + /* read index at the start of receive */ + uint32_t last_rd_idx; + /* last seen write index */ + uint32_t last_seen_wr_idx; +} VMBusRecvRingBuf; + + +enum { + VMOFFER_INIT, + VMOFFER_SENDING, + VMOFFER_SENT, +}; + +enum { + VMCHAN_INIT, + VMCHAN_OPENING, + VMCHAN_OPEN, +}; + +struct VMBusChannel { + VMBusDevice *dev; + + /* channel id */ + uint32_t id; + /* + * subchannel index within the device; subchannel #0 is "primary" and + * always exists + */ + uint16_t subchan_idx; + uint32_t open_id; + /* VP_INDEX of the vCPU to notify with (synthetic) interrupts */ + uint32_t target_vp; + /* GPADL id to use for the ring buffers */ + uint32_t ringbuf_gpadl; + /* start (in pages) of the send ring buffer within @ringbuf_gpadl */ + uint32_t ringbuf_send_offset; + + uint8_t offer_state; + uint8_t state; + bool is_open; + + /* main device worker; copied from the device class */ + VMBusChannelNotifyCb notify_cb; + /* + * guest->host notifications, either sent directly or dispatched via + * interrupt page (older VMBus) + */ + EventNotifier notifier; + + VMBus *vmbus; + /* + * SINT route to signal with host->guest notifications; may be shared with + * the main VMBus SINT route + */ + HvSintRoute *notify_route; + VMBusGpadl *gpadl; + + VMBusSendRingBuf send_ringbuf; + VMBusRecvRingBuf recv_ringbuf; + + QTAILQ_ENTRY(VMBusChannel) link; +}; + +/* + * Hyper-V spec mandates that every message port has 16 buffers, which means + * that the guest can post up to this many messages without blocking. + * Therefore a queue for incoming messages has to be provided. + * For outgoing (i.e. host->guest) messages there's no queue; the VMBus just + * doesn't transition to a new state until the message is known to have been + * successfully delivered to the respective SynIC message slot. + */ +#define HV_MSG_QUEUE_LEN 16 + +/* Hyper-V devices never use channel #0. Must be something special. */ +#define VMBUS_FIRST_CHANID 1 +/* Each channel occupies one bit within a single event page sint slot. */ +#define VMBUS_CHANID_COUNT (HV_EVENT_FLAGS_COUNT - VMBUS_FIRST_CHANID) +/* Leave a few connection numbers for other purposes. */ +#define VMBUS_CHAN_CONNECTION_OFFSET 16 + +/* + * Since the success or failure of sending a message is reported + * asynchronously, the VMBus state machine has effectively two entry points: + * vmbus_run and vmbus_msg_cb (the latter is called when the host->guest + * message delivery status becomes known). Both are run as oneshot BHs on the + * main aio context, ensuring serialization. + */ +enum { + VMBUS_LISTEN, + VMBUS_HANDSHAKE, + VMBUS_OFFER, + VMBUS_CREATE_GPADL, + VMBUS_TEARDOWN_GPADL, + VMBUS_OPEN_CHANNEL, + VMBUS_UNLOAD, + VMBUS_STATE_MAX +}; + +struct VMBus { + BusState parent; + + uint8_t state; + /* protection against recursive aio_poll (see vmbus_run) */ + bool in_progress; + /* whether there's a message being delivered to the guest */ + bool msg_in_progress; + uint32_t version; + /* VP_INDEX of the vCPU to send messages and interrupts to */ + uint32_t target_vp; + HvSintRoute *sint_route; + /* + * interrupt page for older protocol versions; newer ones use SynIC event + * flags directly + */ + hwaddr int_page_gpa; + + DECLARE_BITMAP(chanid_bitmap, VMBUS_CHANID_COUNT); + + /* incoming message queue */ + struct hyperv_post_message_input rx_queue[HV_MSG_QUEUE_LEN]; + uint8_t rx_queue_head; + uint8_t rx_queue_size; + QemuMutex rx_queue_lock; + + QTAILQ_HEAD(, VMBusGpadl) gpadl_list; + QTAILQ_HEAD(, VMBusChannel) channel_list; + + /* + * guest->host notifications for older VMBus, to be dispatched via + * interrupt page + */ + EventNotifier notifier; +}; + +static bool gpadl_full(VMBusGpadl *gpadl) +{ + return gpadl->seen_gfns == gpadl->num_gfns; +} + +static VMBusGpadl *create_gpadl(VMBus *vmbus, uint32_t id, + uint32_t child_relid, uint32_t num_gfns) +{ + VMBusGpadl *gpadl = g_new0(VMBusGpadl, 1); + + gpadl->id = id; + gpadl->child_relid = child_relid; + gpadl->num_gfns = num_gfns; + gpadl->gfns = g_new(uint64_t, num_gfns); + QTAILQ_INSERT_HEAD(&vmbus->gpadl_list, gpadl, link); + gpadl->vmbus = vmbus; + gpadl->refcount = 1; + return gpadl; +} + +static void free_gpadl(VMBusGpadl *gpadl) +{ + QTAILQ_REMOVE(&gpadl->vmbus->gpadl_list, gpadl, link); + g_free(gpadl->gfns); + g_free(gpadl); +} + +static VMBusGpadl *find_gpadl(VMBus *vmbus, uint32_t gpadl_id) +{ + VMBusGpadl *gpadl; + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + if (gpadl->id == gpadl_id) { + return gpadl; + } + } + return NULL; +} + +VMBusGpadl *vmbus_get_gpadl(VMBusChannel *chan, uint32_t gpadl_id) +{ + VMBusGpadl *gpadl = find_gpadl(chan->vmbus, gpadl_id); + if (!gpadl || !gpadl_full(gpadl)) { + return NULL; + } + gpadl->refcount++; + return gpadl; +} + +void vmbus_put_gpadl(VMBusGpadl *gpadl) +{ + if (!gpadl) { + return; + } + if (--gpadl->refcount) { + return; + } + free_gpadl(gpadl); +} + +uint32_t vmbus_gpadl_len(VMBusGpadl *gpadl) +{ + return gpadl->num_gfns * TARGET_PAGE_SIZE; +} + +static void gpadl_iter_init(GpadlIter *iter, VMBusGpadl *gpadl, + AddressSpace *as, DMADirection dir) +{ + iter->gpadl = gpadl; + iter->as = as; + iter->dir = dir; + iter->active = false; +} + +static inline void gpadl_iter_cache_unmap(GpadlIter *iter) +{ + uint32_t map_start_in_page = (uintptr_t)iter->map & ~TARGET_PAGE_MASK; + uint32_t io_end_in_page = ((iter->last_off - 1) & ~TARGET_PAGE_MASK) + 1; + + /* mapping is only done to do non-zero amount of i/o */ + assert(iter->last_off > 0); + assert(map_start_in_page < io_end_in_page); + + dma_memory_unmap(iter->as, iter->map, TARGET_PAGE_SIZE - map_start_in_page, + iter->dir, io_end_in_page - map_start_in_page); +} + +/* + * Copy exactly @len bytes between the GPADL pointed to by @iter and @buf. + * The direction of the copy is determined by @iter->dir. + * The caller must ensure the operation overflows neither @buf nor the GPADL + * (there's an assert for the latter). + * Reuse the currently mapped page in the GPADL if possible. + */ +static ssize_t gpadl_iter_io(GpadlIter *iter, void *buf, uint32_t len) +{ + ssize_t ret = len; + + assert(iter->active); + + while (len) { + uint32_t off_in_page = iter->off & ~TARGET_PAGE_MASK; + uint32_t pgleft = TARGET_PAGE_SIZE - off_in_page; + uint32_t cplen = MIN(pgleft, len); + void *p; + + /* try to reuse the cached mapping */ + if (iter->map) { + uint32_t map_start_in_page = + (uintptr_t)iter->map & ~TARGET_PAGE_MASK; + uint32_t off_base = iter->off & ~TARGET_PAGE_MASK; + uint32_t mapped_base = (iter->last_off - 1) & ~TARGET_PAGE_MASK; + if (off_base != mapped_base || off_in_page < map_start_in_page) { + gpadl_iter_cache_unmap(iter); + iter->map = NULL; + } + } + + if (!iter->map) { + dma_addr_t maddr; + dma_addr_t mlen = pgleft; + uint32_t idx = iter->off >> TARGET_PAGE_BITS; + assert(idx < iter->gpadl->num_gfns); + + maddr = (iter->gpadl->gfns[idx] << TARGET_PAGE_BITS) | off_in_page; + + iter->map = dma_memory_map(iter->as, maddr, &mlen, iter->dir); + if (mlen != pgleft) { + dma_memory_unmap(iter->as, iter->map, mlen, iter->dir, 0); + iter->map = NULL; + return -EFAULT; + } + } + + p = (void *)(((uintptr_t)iter->map & TARGET_PAGE_MASK) | off_in_page); + if (iter->dir == DMA_DIRECTION_FROM_DEVICE) { + memcpy(p, buf, cplen); + } else { + memcpy(buf, p, cplen); + } + + buf += cplen; + len -= cplen; + iter->off += cplen; + iter->last_off = iter->off; + } + + return ret; +} + +/* + * Position the iterator @iter at new offset @new_off. + * If this results in the cached mapping being unusable with the new offset, + * unmap it. + */ +static inline void gpadl_iter_seek(GpadlIter *iter, uint32_t new_off) +{ + assert(iter->active); + iter->off = new_off; +} + +/* + * Start a series of i/o on the GPADL. + * After this i/o and seek operations on @iter become legal. + */ +static inline void gpadl_iter_start_io(GpadlIter *iter) +{ + assert(!iter->active); + /* mapping is cached lazily on i/o */ + iter->map = NULL; + iter->active = true; +} + +/* + * End the eariler started series of i/o on the GPADL and release the cached + * mapping if any. + */ +static inline void gpadl_iter_end_io(GpadlIter *iter) +{ + assert(iter->active); + + if (iter->map) { + gpadl_iter_cache_unmap(iter); + } + + iter->active = false; +} + +static void vmbus_resched(VMBus *vmbus); +static void vmbus_msg_cb(void *data, int status); + +ssize_t vmbus_iov_to_gpadl(VMBusChannel *chan, VMBusGpadl *gpadl, uint32_t off, + const struct iovec *iov, size_t iov_cnt) +{ + GpadlIter iter; + size_t i; + ssize_t ret = 0; + + gpadl_iter_init(&iter, gpadl, chan->dev->dma_as, + DMA_DIRECTION_FROM_DEVICE); + gpadl_iter_start_io(&iter); + gpadl_iter_seek(&iter, off); + for (i = 0; i < iov_cnt; i++) { + ret = gpadl_iter_io(&iter, iov[i].iov_base, iov[i].iov_len); + if (ret < 0) { + goto out; + } + } +out: + gpadl_iter_end_io(&iter); + return ret; +} + +int vmbus_map_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov, + unsigned iov_cnt, size_t len, size_t off) +{ + int ret_cnt = 0, ret; + unsigned i; + QEMUSGList *sgl = &req->sgl; + ScatterGatherEntry *sg = sgl->sg; + + for (i = 0; i < sgl->nsg; i++) { + if (sg[i].len > off) { + break; + } + off -= sg[i].len; + } + for (; len && i < sgl->nsg; i++) { + dma_addr_t mlen = MIN(sg[i].len - off, len); + dma_addr_t addr = sg[i].base + off; + len -= mlen; + off = 0; + + for (; mlen; ret_cnt++) { + dma_addr_t l = mlen; + dma_addr_t a = addr; + + if (ret_cnt == iov_cnt) { + ret = -ENOBUFS; + goto err; + } + + iov[ret_cnt].iov_base = dma_memory_map(sgl->as, a, &l, dir); + if (!l) { + ret = -EFAULT; + goto err; + } + iov[ret_cnt].iov_len = l; + addr += l; + mlen -= l; + } + } + + return ret_cnt; +err: + vmbus_unmap_sgl(req, dir, iov, ret_cnt, 0); + return ret; +} + +void vmbus_unmap_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov, + unsigned iov_cnt, size_t accessed) +{ + QEMUSGList *sgl = &req->sgl; + unsigned i; + + for (i = 0; i < iov_cnt; i++) { + size_t acsd = MIN(accessed, iov[i].iov_len); + dma_memory_unmap(sgl->as, iov[i].iov_base, iov[i].iov_len, dir, acsd); + accessed -= acsd; + } +} + +static const VMStateDescription vmstate_gpadl = { + .name = "vmbus/gpadl", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_UINT32(id, VMBusGpadl), + VMSTATE_UINT32(child_relid, VMBusGpadl), + VMSTATE_UINT32(num_gfns, VMBusGpadl), + VMSTATE_UINT32(seen_gfns, VMBusGpadl), + VMSTATE_VARRAY_UINT32_ALLOC(gfns, VMBusGpadl, num_gfns, 0, + vmstate_info_uint64, uint64_t), + VMSTATE_UINT8(state, VMBusGpadl), + VMSTATE_END_OF_LIST() + } +}; + +/* + * Wrap the index into a ring buffer of @len bytes. + * @idx is assumed not to exceed twice the size of the ringbuffer, so only + * single wraparound is considered. + */ +static inline uint32_t rb_idx_wrap(uint32_t idx, uint32_t len) +{ + if (idx >= len) { + idx -= len; + } + return idx; +} + +/* + * Circular difference between two indices into a ring buffer of @len bytes. + * @allow_catchup - whether @idx1 may catch up @idx2; e.g. read index may catch + * up write index but not vice versa. + */ +static inline uint32_t rb_idx_delta(uint32_t idx1, uint32_t idx2, uint32_t len, + bool allow_catchup) +{ + return rb_idx_wrap(idx2 + len - idx1 - !allow_catchup, len); +} + +static vmbus_ring_buffer *ringbuf_map_hdr(VMBusRingBufCommon *ringbuf) +{ + vmbus_ring_buffer *rb; + dma_addr_t mlen = sizeof(*rb); + + rb = dma_memory_map(ringbuf->as, ringbuf->rb_addr, &mlen, + DMA_DIRECTION_FROM_DEVICE); + if (mlen != sizeof(*rb)) { + dma_memory_unmap(ringbuf->as, rb, mlen, + DMA_DIRECTION_FROM_DEVICE, 0); + return NULL; + } + return rb; +} + +static void ringbuf_unmap_hdr(VMBusRingBufCommon *ringbuf, + vmbus_ring_buffer *rb, bool dirty) +{ + assert(rb); + + dma_memory_unmap(ringbuf->as, rb, sizeof(*rb), DMA_DIRECTION_FROM_DEVICE, + dirty ? sizeof(*rb) : 0); +} + +static void ringbuf_init_common(VMBusRingBufCommon *ringbuf, VMBusGpadl *gpadl, + AddressSpace *as, DMADirection dir, + uint32_t begin, uint32_t end) +{ + ringbuf->as = as; + ringbuf->rb_addr = gpadl->gfns[begin] << TARGET_PAGE_BITS; + ringbuf->base = (begin + 1) << TARGET_PAGE_BITS; + ringbuf->len = (end - begin - 1) << TARGET_PAGE_BITS; + gpadl_iter_init(&ringbuf->iter, gpadl, as, dir); +} + +static int ringbufs_init(VMBusChannel *chan) +{ + vmbus_ring_buffer *rb; + VMBusSendRingBuf *send_ringbuf = &chan->send_ringbuf; + VMBusRecvRingBuf *recv_ringbuf = &chan->recv_ringbuf; + + if (chan->ringbuf_send_offset <= 1 || + chan->gpadl->num_gfns <= chan->ringbuf_send_offset + 1) { + return -EINVAL; + } + + ringbuf_init_common(&recv_ringbuf->common, chan->gpadl, chan->dev->dma_as, + DMA_DIRECTION_TO_DEVICE, 0, chan->ringbuf_send_offset); + ringbuf_init_common(&send_ringbuf->common, chan->gpadl, chan->dev->dma_as, + DMA_DIRECTION_FROM_DEVICE, chan->ringbuf_send_offset, + chan->gpadl->num_gfns); + send_ringbuf->wanted = 0; + send_ringbuf->reserved = 0; + + rb = ringbuf_map_hdr(&recv_ringbuf->common); + if (!rb) { + return -EFAULT; + } + recv_ringbuf->rd_idx = recv_ringbuf->last_rd_idx = rb->read_index; + ringbuf_unmap_hdr(&recv_ringbuf->common, rb, false); + + rb = ringbuf_map_hdr(&send_ringbuf->common); + if (!rb) { + return -EFAULT; + } + send_ringbuf->wr_idx = send_ringbuf->last_wr_idx = rb->write_index; + send_ringbuf->last_seen_rd_idx = rb->read_index; + rb->feature_bits |= VMBUS_RING_BUFFER_FEAT_PENDING_SZ; + ringbuf_unmap_hdr(&send_ringbuf->common, rb, true); + + if (recv_ringbuf->rd_idx >= recv_ringbuf->common.len || + send_ringbuf->wr_idx >= send_ringbuf->common.len) { + return -EOVERFLOW; + } + + return 0; +} + +/* + * Perform io between the GPADL-backed ringbuffer @ringbuf and @buf, wrapping + * around if needed. + * @len is assumed not to exceed the size of the ringbuffer, so only single + * wraparound is considered. + */ +static ssize_t ringbuf_io(VMBusRingBufCommon *ringbuf, void *buf, uint32_t len) +{ + ssize_t ret1 = 0, ret2 = 0; + uint32_t remain = ringbuf->len + ringbuf->base - ringbuf->iter.off; + + if (len >= remain) { + ret1 = gpadl_iter_io(&ringbuf->iter, buf, remain); + if (ret1 < 0) { + return ret1; + } + gpadl_iter_seek(&ringbuf->iter, ringbuf->base); + buf += remain; + len -= remain; + } + ret2 = gpadl_iter_io(&ringbuf->iter, buf, len); + if (ret2 < 0) { + return ret2; + } + return ret1 + ret2; +} + +/* + * Position the circular iterator within @ringbuf to offset @new_off, wrapping + * around if needed. + * @new_off is assumed not to exceed twice the size of the ringbuffer, so only + * single wraparound is considered. + */ +static inline void ringbuf_seek(VMBusRingBufCommon *ringbuf, uint32_t new_off) +{ + gpadl_iter_seek(&ringbuf->iter, + ringbuf->base + rb_idx_wrap(new_off, ringbuf->len)); +} + +static inline uint32_t ringbuf_tell(VMBusRingBufCommon *ringbuf) +{ + return ringbuf->iter.off - ringbuf->base; +} + +static inline void ringbuf_start_io(VMBusRingBufCommon *ringbuf) +{ + gpadl_iter_start_io(&ringbuf->iter); +} + +static inline void ringbuf_end_io(VMBusRingBufCommon *ringbuf) +{ + gpadl_iter_end_io(&ringbuf->iter); +} + +VMBusDevice *vmbus_channel_device(VMBusChannel *chan) +{ + return chan->dev; +} + +VMBusChannel *vmbus_device_channel(VMBusDevice *dev, uint32_t chan_idx) +{ + if (chan_idx >= dev->num_channels) { + return NULL; + } + return &dev->channels[chan_idx]; +} + +uint32_t vmbus_channel_idx(VMBusChannel *chan) +{ + return chan - chan->dev->channels; +} + +void vmbus_channel_notify_host(VMBusChannel *chan) +{ + event_notifier_set(&chan->notifier); +} + +bool vmbus_channel_is_open(VMBusChannel *chan) +{ + return chan->is_open; +} + +/* + * Notify the guest side about the data to work on in the channel ring buffer. + * The notification is done by signaling a dedicated per-channel SynIC event + * flag (more recent guests) or setting a bit in the interrupt page and firing + * the VMBus SINT (older guests). + */ +static int vmbus_channel_notify_guest(VMBusChannel *chan) +{ + int res = 0; + unsigned long *int_map, mask; + unsigned idx; + hwaddr addr = chan->vmbus->int_page_gpa; + hwaddr len = TARGET_PAGE_SIZE / 2, dirty = 0; + + trace_vmbus_channel_notify_guest(chan->id); + + if (!addr) { + return hyperv_set_event_flag(chan->notify_route, chan->id); + } + + int_map = cpu_physical_memory_map(addr, &len, 1); + if (len != TARGET_PAGE_SIZE / 2) { + res = -ENXIO; + goto unmap; + } + + idx = BIT_WORD(chan->id); + mask = BIT_MASK(chan->id); + if ((atomic_fetch_or(&int_map[idx], mask) & mask) != mask) { + res = hyperv_sint_route_set_sint(chan->notify_route); + dirty = len; + } + +unmap: + cpu_physical_memory_unmap(int_map, len, 1, dirty); + return res; +} + +#define VMBUS_PKT_TRAILER sizeof(uint64_t) + +static uint32_t vmbus_pkt_hdr_set_offsets(vmbus_packet_hdr *hdr, + uint32_t desclen, uint32_t msglen) +{ + hdr->offset_qwords = sizeof(*hdr) / sizeof(uint64_t) + + DIV_ROUND_UP(desclen, sizeof(uint64_t)); + hdr->len_qwords = hdr->offset_qwords + + DIV_ROUND_UP(msglen, sizeof(uint64_t)); + return hdr->len_qwords * sizeof(uint64_t) + VMBUS_PKT_TRAILER; +} + +/* + * Simplified ring buffer operation with paired barriers annotations in the + * producer and consumer loops: + * + * producer * consumer + * ~~~~~~~~ * ~~~~~~~~ + * write pending_send_sz * read write_index + * smp_mb [A] * smp_mb [C] + * read read_index * read packet + * smp_mb [B] * read/write out-of-band data + * read/write out-of-band data * smp_mb [B] + * write packet * write read_index + * smp_mb [C] * smp_mb [A] + * write write_index * read pending_send_sz + * smp_wmb [D] * smp_rmb [D] + * write pending_send_sz * read write_index + * ... * ... + */ + +static inline uint32_t ringbuf_send_avail(VMBusSendRingBuf *ringbuf) +{ + /* don't trust guest data */ + if (ringbuf->last_seen_rd_idx >= ringbuf->common.len) { + return 0; + } + return rb_idx_delta(ringbuf->wr_idx, ringbuf->last_seen_rd_idx, + ringbuf->common.len, false); +} + +static ssize_t ringbuf_send_update_idx(VMBusChannel *chan) +{ + VMBusSendRingBuf *ringbuf = &chan->send_ringbuf; + vmbus_ring_buffer *rb; + uint32_t written; + + written = rb_idx_delta(ringbuf->last_wr_idx, ringbuf->wr_idx, + ringbuf->common.len, true); + if (!written) { + return 0; + } + + rb = ringbuf_map_hdr(&ringbuf->common); + if (!rb) { + return -EFAULT; + } + + ringbuf->reserved -= written; + + /* prevent reorder with the data operation and packet write */ + smp_mb(); /* barrier pair [C] */ + rb->write_index = ringbuf->wr_idx; + + /* + * If the producer earlier indicated that it wants to be notified when the + * consumer frees certain amount of space in the ring buffer, that amount + * is reduced by the size of the completed write. + */ + if (ringbuf->wanted) { + /* otherwise reservation would fail */ + assert(ringbuf->wanted < written); + ringbuf->wanted -= written; + /* prevent reorder with write_index write */ + smp_wmb(); /* barrier pair [D] */ + rb->pending_send_sz = ringbuf->wanted; + } + + /* prevent reorder with write_index or pending_send_sz write */ + smp_mb(); /* barrier pair [A] */ + ringbuf->last_seen_rd_idx = rb->read_index; + + /* + * The consumer may have missed the reduction of pending_send_sz and skip + * notification, so re-check the blocking condition, and, if it's no longer + * true, ensure processing another iteration by simulating consumer's + * notification. + */ + if (ringbuf_send_avail(ringbuf) >= ringbuf->wanted) { + vmbus_channel_notify_host(chan); + } + + /* skip notification by consumer's request */ + if (rb->interrupt_mask) { + goto out; + } + + /* + * The consumer hasn't caught up with the producer's previous state so it's + * not blocked. + * (last_seen_rd_idx comes from the guest but it's safe to use w/o + * validation here as it only affects notification.) + */ + if (rb_idx_delta(ringbuf->last_seen_rd_idx, ringbuf->wr_idx, + ringbuf->common.len, true) > written) { + goto out; + } + + vmbus_channel_notify_guest(chan); +out: + ringbuf_unmap_hdr(&ringbuf->common, rb, true); + ringbuf->last_wr_idx = ringbuf->wr_idx; + return written; +} + +int vmbus_channel_reserve(VMBusChannel *chan, + uint32_t desclen, uint32_t msglen) +{ + VMBusSendRingBuf *ringbuf = &chan->send_ringbuf; + vmbus_ring_buffer *rb = NULL; + vmbus_packet_hdr hdr; + uint32_t needed = ringbuf->reserved + + vmbus_pkt_hdr_set_offsets(&hdr, desclen, msglen); + + /* avoid touching the guest memory if possible */ + if (likely(needed <= ringbuf_send_avail(ringbuf))) { + goto success; + } + + rb = ringbuf_map_hdr(&ringbuf->common); + if (!rb) { + return -EFAULT; + } + + /* fetch read index from guest memory and try again */ + ringbuf->last_seen_rd_idx = rb->read_index; + + if (likely(needed <= ringbuf_send_avail(ringbuf))) { + goto success; + } + + rb->pending_send_sz = needed; + + /* + * The consumer may have made progress and freed up some space before + * seeing updated pending_send_sz, so re-read read_index (preventing + * reorder with the pending_send_sz write) and try again. + */ + smp_mb(); /* barrier pair [A] */ + ringbuf->last_seen_rd_idx = rb->read_index; + + if (needed > ringbuf_send_avail(ringbuf)) { + goto out; + } + +success: + ringbuf->reserved = needed; + needed = 0; + + /* clear pending_send_sz if it was set */ + if (ringbuf->wanted) { + if (!rb) { + rb = ringbuf_map_hdr(&ringbuf->common); + if (!rb) { + /* failure to clear pending_send_sz is non-fatal */ + goto out; + } + } + + rb->pending_send_sz = 0; + } + + /* prevent reorder of the following data operation with read_index read */ + smp_mb(); /* barrier pair [B] */ + +out: + if (rb) { + ringbuf_unmap_hdr(&ringbuf->common, rb, ringbuf->wanted == needed); + } + ringbuf->wanted = needed; + return needed ? -ENOSPC : 0; +} + +ssize_t vmbus_channel_send(VMBusChannel *chan, uint16_t pkt_type, + void *desc, uint32_t desclen, + void *msg, uint32_t msglen, + bool need_comp, uint64_t transaction_id) +{ + ssize_t ret = 0; + vmbus_packet_hdr hdr; + uint32_t totlen; + VMBusSendRingBuf *ringbuf = &chan->send_ringbuf; + + if (!vmbus_channel_is_open(chan)) { + return -EINVAL; + } + + totlen = vmbus_pkt_hdr_set_offsets(&hdr, desclen, msglen); + hdr.type = pkt_type; + hdr.flags = need_comp ? VMBUS_PACKET_FLAG_REQUEST_COMPLETION : 0; + hdr.transaction_id = transaction_id; + + assert(totlen <= ringbuf->reserved); + + ringbuf_start_io(&ringbuf->common); + ringbuf_seek(&ringbuf->common, ringbuf->wr_idx); + ret = ringbuf_io(&ringbuf->common, &hdr, sizeof(hdr)); + if (ret < 0) { + goto out; + } + if (desclen) { + assert(desc); + ret = ringbuf_io(&ringbuf->common, desc, desclen); + if (ret < 0) { + goto out; + } + ringbuf_seek(&ringbuf->common, + ringbuf->wr_idx + hdr.offset_qwords * sizeof(uint64_t)); + } + ret = ringbuf_io(&ringbuf->common, msg, msglen); + if (ret < 0) { + goto out; + } + ringbuf_seek(&ringbuf->common, ringbuf->wr_idx + totlen); + ringbuf->wr_idx = ringbuf_tell(&ringbuf->common); + ret = 0; +out: + ringbuf_end_io(&ringbuf->common); + if (ret) { + return ret; + } + return ringbuf_send_update_idx(chan); +} + +ssize_t vmbus_channel_send_completion(VMBusChanReq *req, + void *msg, uint32_t msglen) +{ + assert(req->need_comp); + return vmbus_channel_send(req->chan, VMBUS_PACKET_COMP, NULL, 0, + msg, msglen, false, req->transaction_id); +} + +static int sgl_from_gpa_ranges(QEMUSGList *sgl, VMBusDevice *dev, + VMBusRingBufCommon *ringbuf, uint32_t len) +{ + int ret; + vmbus_pkt_gpa_direct hdr; + hwaddr curaddr = 0; + hwaddr curlen = 0; + int num; + + if (len < sizeof(hdr)) { + return -EIO; + } + ret = ringbuf_io(ringbuf, &hdr, sizeof(hdr)); + if (ret < 0) { + return ret; + } + len -= sizeof(hdr); + + num = (len - hdr.rangecount * sizeof(vmbus_gpa_range)) / sizeof(uint64_t); + if (num < 0) { + return -EIO; + } + qemu_sglist_init(sgl, DEVICE(dev), num, ringbuf->as); + + for (; hdr.rangecount; hdr.rangecount--) { + vmbus_gpa_range range; + + if (len < sizeof(range)) { + goto eio; + } + ret = ringbuf_io(ringbuf, &range, sizeof(range)); + if (ret < 0) { + goto err; + } + len -= sizeof(range); + + if (range.byte_offset & TARGET_PAGE_MASK) { + goto eio; + } + + for (; range.byte_count; range.byte_offset = 0) { + uint64_t paddr; + uint32_t plen = MIN(range.byte_count, + TARGET_PAGE_SIZE - range.byte_offset); + + if (len < sizeof(uint64_t)) { + goto eio; + } + ret = ringbuf_io(ringbuf, &paddr, sizeof(paddr)); + if (ret < 0) { + goto err; + } + len -= sizeof(uint64_t); + paddr <<= TARGET_PAGE_BITS; + paddr |= range.byte_offset; + range.byte_count -= plen; + + if (curaddr + curlen == paddr) { + /* consecutive fragments - join */ + curlen += plen; + } else { + if (curlen) { + qemu_sglist_add(sgl, curaddr, curlen); + } + + curaddr = paddr; + curlen = plen; + } + } + } + + if (curlen) { + qemu_sglist_add(sgl, curaddr, curlen); + } + + return 0; +eio: + ret = -EIO; +err: + qemu_sglist_destroy(sgl); + return ret; +} + +static VMBusChanReq *vmbus_alloc_req(VMBusChannel *chan, + uint32_t size, uint16_t pkt_type, + uint32_t msglen, uint64_t transaction_id, + bool need_comp) +{ + VMBusChanReq *req; + uint32_t msgoff = QEMU_ALIGN_UP(size, __alignof__(*req->msg)); + uint32_t totlen = msgoff + msglen; + + req = g_malloc0(totlen); + req->chan = chan; + req->pkt_type = pkt_type; + req->msg = (void *)req + msgoff; + req->msglen = msglen; + req->transaction_id = transaction_id; + req->need_comp = need_comp; + return req; +} + +int vmbus_channel_recv_start(VMBusChannel *chan) +{ + VMBusRecvRingBuf *ringbuf = &chan->recv_ringbuf; + vmbus_ring_buffer *rb; + + rb = ringbuf_map_hdr(&ringbuf->common); + if (!rb) { + return -EFAULT; + } + ringbuf->last_seen_wr_idx = rb->write_index; + ringbuf_unmap_hdr(&ringbuf->common, rb, false); + + if (ringbuf->last_seen_wr_idx >= ringbuf->common.len) { + return -EOVERFLOW; + } + + /* prevent reorder of the following data operation with write_index read */ + smp_mb(); /* barrier pair [C] */ + return 0; +} + +void *vmbus_channel_recv_peek(VMBusChannel *chan, uint32_t size) +{ + VMBusRecvRingBuf *ringbuf = &chan->recv_ringbuf; + vmbus_packet_hdr hdr = {}; + VMBusChanReq *req; + uint32_t avail; + uint32_t totlen, pktlen, msglen, msgoff, desclen; + + assert(size >= sizeof(*req)); + + /* safe as last_seen_wr_idx is validated in vmbus_channel_recv_start */ + avail = rb_idx_delta(ringbuf->rd_idx, ringbuf->last_seen_wr_idx, + ringbuf->common.len, true); + if (avail < sizeof(hdr)) { + return NULL; + } + + ringbuf_seek(&ringbuf->common, ringbuf->rd_idx); + if (ringbuf_io(&ringbuf->common, &hdr, sizeof(hdr)) < 0) { + return NULL; + } + + pktlen = hdr.len_qwords * sizeof(uint64_t); + totlen = pktlen + VMBUS_PKT_TRAILER; + if (totlen > avail) { + return NULL; + } + + msgoff = hdr.offset_qwords * sizeof(uint64_t); + if (msgoff > pktlen || msgoff < sizeof(hdr)) { + error_report("%s: malformed packet: %u %u", __func__, msgoff, pktlen); + return NULL; + } + + msglen = pktlen - msgoff; + + req = vmbus_alloc_req(chan, size, hdr.type, msglen, hdr.transaction_id, + hdr.flags & VMBUS_PACKET_FLAG_REQUEST_COMPLETION); + + switch (hdr.type) { + case VMBUS_PACKET_DATA_USING_GPA_DIRECT: + desclen = msgoff - sizeof(hdr); + if (sgl_from_gpa_ranges(&req->sgl, chan->dev, &ringbuf->common, + desclen) < 0) { + error_report("%s: failed to convert GPA ranges to SGL", __func__); + goto free_req; + } + break; + case VMBUS_PACKET_DATA_INBAND: + case VMBUS_PACKET_COMP: + break; + default: + error_report("%s: unexpected msg type: %x", __func__, hdr.type); + goto free_req; + } + + ringbuf_seek(&ringbuf->common, ringbuf->rd_idx + msgoff); + if (ringbuf_io(&ringbuf->common, req->msg, msglen) < 0) { + goto free_req; + } + ringbuf_seek(&ringbuf->common, ringbuf->rd_idx + totlen); + + return req; +free_req: + vmbus_free_req(req); + return NULL; +} + +void vmbus_channel_recv_pop(VMBusChannel *chan) +{ + VMBusRecvRingBuf *ringbuf = &chan->recv_ringbuf; + ringbuf->rd_idx = ringbuf_tell(&ringbuf->common); +} + +ssize_t vmbus_channel_recv_done(VMBusChannel *chan) +{ + VMBusRecvRingBuf *ringbuf = &chan->recv_ringbuf; + vmbus_ring_buffer *rb; + uint32_t read; + + read = rb_idx_delta(ringbuf->last_rd_idx, ringbuf->rd_idx, + ringbuf->common.len, true); + if (!read) { + return 0; + } + + rb = ringbuf_map_hdr(&ringbuf->common); + if (!rb) { + return -EFAULT; + } + + /* prevent reorder with the data operation and packet read */ + smp_mb(); /* barrier pair [B] */ + rb->read_index = ringbuf->rd_idx; + + /* prevent reorder of the following pending_send_sz read */ + smp_mb(); /* barrier pair [A] */ + + if (rb->interrupt_mask) { + goto out; + } + + if (rb->feature_bits & VMBUS_RING_BUFFER_FEAT_PENDING_SZ) { + uint32_t wr_idx, wr_avail; + uint32_t wanted = rb->pending_send_sz; + + if (!wanted) { + goto out; + } + + /* prevent reorder with pending_send_sz read */ + smp_rmb(); /* barrier pair [D] */ + wr_idx = rb->write_index; + + wr_avail = rb_idx_delta(wr_idx, ringbuf->rd_idx, ringbuf->common.len, + true); + + /* the producer wasn't blocked on the consumer state */ + if (wr_avail >= read + wanted) { + goto out; + } + /* there's not enough space for the producer to make progress */ + if (wr_avail < wanted) { + goto out; + } + } + + vmbus_channel_notify_guest(chan); +out: + ringbuf_unmap_hdr(&ringbuf->common, rb, true); + ringbuf->last_rd_idx = ringbuf->rd_idx; + return read; +} + +void vmbus_free_req(void *req) +{ + VMBusChanReq *r = req; + + if (!req) { + return; + } + + if (r->sgl.dev) { + qemu_sglist_destroy(&r->sgl); + } + g_free(req); +} + +static void channel_event_cb(EventNotifier *e) +{ + VMBusChannel *chan = container_of(e, VMBusChannel, notifier); + if (event_notifier_test_and_clear(e)) { + /* + * All receives are supposed to happen within the device worker, so + * bracket it with ringbuf_start/end_io on the receive ringbuffer, and + * potentially reuse the cached mapping throughout the worker. + * Can't do this for sends as they may happen outside the device + * worker. + */ + VMBusRecvRingBuf *ringbuf = &chan->recv_ringbuf; + ringbuf_start_io(&ringbuf->common); + chan->notify_cb(chan); + ringbuf_end_io(&ringbuf->common); + + } +} + +static int alloc_chan_id(VMBus *vmbus) +{ + int ret; + + ret = find_next_zero_bit(vmbus->chanid_bitmap, VMBUS_CHANID_COUNT, 0); + if (ret == VMBUS_CHANID_COUNT) { + return -ENOMEM; + } + return ret + VMBUS_FIRST_CHANID; +} + +static int register_chan_id(VMBusChannel *chan) +{ + return test_and_set_bit(chan->id - VMBUS_FIRST_CHANID, + chan->vmbus->chanid_bitmap) ? -EEXIST : 0; +} + +static void unregister_chan_id(VMBusChannel *chan) +{ + clear_bit(chan->id - VMBUS_FIRST_CHANID, chan->vmbus->chanid_bitmap); +} + +static uint32_t chan_connection_id(VMBusChannel *chan) +{ + return VMBUS_CHAN_CONNECTION_OFFSET + chan->id; +} + +static void init_channel(VMBus *vmbus, VMBusDevice *dev, VMBusDeviceClass *vdc, + VMBusChannel *chan, uint16_t idx, Error **errp) +{ + int res; + + chan->dev = dev; + chan->notify_cb = vdc->chan_notify_cb; + chan->subchan_idx = idx; + chan->vmbus = vmbus; + + res = alloc_chan_id(vmbus); + if (res < 0) { + error_setg(errp, "no spare channel id"); + return; + } + chan->id = res; + register_chan_id(chan); + + /* + * The guest drivers depend on the device subchannels (idx #1+) to be + * offered after the primary channel (idx #0) of that device. To ensure + * that, record the channels on the channel list in the order they appear + * within the device. + */ + QTAILQ_INSERT_TAIL(&vmbus->channel_list, chan, link); +} + +static void deinit_channel(VMBusChannel *chan) +{ + assert(chan->state == VMCHAN_INIT); + QTAILQ_REMOVE(&chan->vmbus->channel_list, chan, link); + unregister_chan_id(chan); +} + +static void create_channels(VMBus *vmbus, VMBusDevice *dev, Error **errp) +{ + uint16_t i; + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(dev); + Error *err = NULL; + + dev->num_channels = vdc->num_channels ? vdc->num_channels(dev) : 1; + if (dev->num_channels < 1) { + error_setg(&err, "invalid #channels: %u", dev->num_channels); + goto error_out; + } + + dev->channels = g_new0(VMBusChannel, dev->num_channels); + for (i = 0; i < dev->num_channels; i++) { + init_channel(vmbus, dev, vdc, &dev->channels[i], i, &err); + if (err) { + goto err_init; + } + } + + return; + +err_init: + while (i--) { + deinit_channel(&dev->channels[i]); + } +error_out: + error_propagate(errp, err); +} + +static void free_channels(VMBusDevice *dev) +{ + uint16_t i; + for (i = 0; i < dev->num_channels; i++) { + deinit_channel(&dev->channels[i]); + } + g_free(dev->channels); +} + +static HvSintRoute *make_sint_route(VMBus *vmbus, uint32_t vp_index) +{ + VMBusChannel *chan; + + if (vp_index == vmbus->target_vp) { + hyperv_sint_route_ref(vmbus->sint_route); + return vmbus->sint_route; + } + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->target_vp == vp_index && vmbus_channel_is_open(chan)) { + hyperv_sint_route_ref(chan->notify_route); + return chan->notify_route; + } + } + + return hyperv_sint_route_new(vp_index, VMBUS_SINT, NULL, NULL); +} + +static void open_channel(VMBusChannel *chan) +{ + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(chan->dev); + + chan->gpadl = vmbus_get_gpadl(chan, chan->ringbuf_gpadl); + if (!chan->gpadl) { + return; + } + + if (ringbufs_init(chan)) { + goto put_gpadl; + } + + if (event_notifier_init(&chan->notifier, 0)) { + goto put_gpadl; + } + + event_notifier_set_handler(&chan->notifier, channel_event_cb); + + if (hyperv_set_event_flag_handler(chan_connection_id(chan), + &chan->notifier)) { + goto cleanup_notifier; + } + + chan->notify_route = make_sint_route(chan->vmbus, chan->target_vp); + if (!chan->notify_route) { + goto clear_event_flag_handler; + } + + if (vdc->open_channel && vdc->open_channel(chan)) { + goto unref_sint_route; + } + + chan->is_open = true; + return; + +unref_sint_route: + hyperv_sint_route_unref(chan->notify_route); +clear_event_flag_handler: + hyperv_set_event_flag_handler(chan_connection_id(chan), NULL); +cleanup_notifier: + event_notifier_set_handler(&chan->notifier, NULL); + event_notifier_cleanup(&chan->notifier); +put_gpadl: + vmbus_put_gpadl(chan->gpadl); +} + +static void close_channel(VMBusChannel *chan) +{ + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(chan->dev); + + if (!chan->is_open) { + return; + } + + if (vdc->close_channel) { + vdc->close_channel(chan); + } + + hyperv_sint_route_unref(chan->notify_route); + hyperv_set_event_flag_handler(chan_connection_id(chan), NULL); + event_notifier_set_handler(&chan->notifier, NULL); + event_notifier_cleanup(&chan->notifier); + vmbus_put_gpadl(chan->gpadl); + chan->is_open = false; +} + +static int channel_post_load(void *opaque, int version_id) +{ + VMBusChannel *chan = opaque; + + return register_chan_id(chan); +} + +static const VMStateDescription vmstate_channel = { + .name = "vmbus/channel", + .version_id = 0, + .minimum_version_id = 0, + .post_load = channel_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT32(id, VMBusChannel), + VMSTATE_UINT16(subchan_idx, VMBusChannel), + VMSTATE_UINT32(open_id, VMBusChannel), + VMSTATE_UINT32(target_vp, VMBusChannel), + VMSTATE_UINT32(ringbuf_gpadl, VMBusChannel), + VMSTATE_UINT32(ringbuf_send_offset, VMBusChannel), + VMSTATE_UINT8(offer_state, VMBusChannel), + VMSTATE_UINT8(state, VMBusChannel), + VMSTATE_END_OF_LIST() + } +}; + +static VMBusChannel *find_channel(VMBus *vmbus, uint32_t id) +{ + VMBusChannel *chan; + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->id == id) { + return chan; + } + } + return NULL; +} + +static int enqueue_incoming_message(VMBus *vmbus, + const struct hyperv_post_message_input *msg) +{ + int ret = 0; + uint8_t idx, prev_size; + + qemu_mutex_lock(&vmbus->rx_queue_lock); + + if (vmbus->rx_queue_size == HV_MSG_QUEUE_LEN) { + ret = -ENOBUFS; + goto out; + } + + prev_size = vmbus->rx_queue_size; + idx = (vmbus->rx_queue_head + vmbus->rx_queue_size) % HV_MSG_QUEUE_LEN; + memcpy(&vmbus->rx_queue[idx], msg, sizeof(*msg)); + vmbus->rx_queue_size++; + + /* only need to resched if the queue was empty before */ + if (!prev_size) { + vmbus_resched(vmbus); + } +out: + qemu_mutex_unlock(&vmbus->rx_queue_lock); + return ret; +} + +static uint16_t vmbus_recv_message(const struct hyperv_post_message_input *msg, + void *data) +{ + VMBus *vmbus = data; + struct vmbus_message_header *vmbus_msg; + + if (msg->message_type != HV_MESSAGE_VMBUS) { + return HV_STATUS_INVALID_HYPERCALL_INPUT; + } + + if (msg->payload_size < sizeof(struct vmbus_message_header)) { + return HV_STATUS_INVALID_HYPERCALL_INPUT; + } + + vmbus_msg = (struct vmbus_message_header *)msg->payload; + + trace_vmbus_recv_message(vmbus_msg->message_type, msg->payload_size); + + if (vmbus_msg->message_type == VMBUS_MSG_INVALID || + vmbus_msg->message_type >= VMBUS_MSG_COUNT) { + error_report("vmbus: unknown message type %#x", + vmbus_msg->message_type); + return HV_STATUS_INVALID_HYPERCALL_INPUT; + } + + if (enqueue_incoming_message(vmbus, msg)) { + return HV_STATUS_INSUFFICIENT_BUFFERS; + } + return HV_STATUS_SUCCESS; +} + +static bool vmbus_initialized(VMBus *vmbus) +{ + return vmbus->version > 0 && vmbus->version <= VMBUS_VERSION_CURRENT; +} + +static void vmbus_reset_all(VMBus *vmbus) +{ + qbus_reset_all(BUS(vmbus)); +} + +static void post_msg(VMBus *vmbus, void *msgdata, uint32_t msglen) +{ + int ret; + struct hyperv_message msg = { + .header.message_type = HV_MESSAGE_VMBUS, + }; + + assert(!vmbus->msg_in_progress); + assert(msglen <= sizeof(msg.payload)); + assert(msglen >= sizeof(struct vmbus_message_header)); + + vmbus->msg_in_progress = true; + + trace_vmbus_post_msg(((struct vmbus_message_header *)msgdata)->message_type, + msglen); + + memcpy(msg.payload, msgdata, msglen); + msg.header.payload_size = ROUND_UP(msglen, VMBUS_MESSAGE_SIZE_ALIGN); + + ret = hyperv_post_msg(vmbus->sint_route, &msg); + if (ret == 0 || ret == -EAGAIN) { + return; + } + + error_report("message delivery fatal failure: %d; aborting vmbus", ret); + vmbus_reset_all(vmbus); +} + +static int vmbus_init(VMBus *vmbus) +{ + if (vmbus->target_vp != (uint32_t)-1) { + vmbus->sint_route = hyperv_sint_route_new(vmbus->target_vp, VMBUS_SINT, + vmbus_msg_cb, vmbus); + if (!vmbus->sint_route) { + error_report("failed to set up SINT route"); + return -ENOMEM; + } + } + return 0; +} + +static void vmbus_deinit(VMBus *vmbus) +{ + VMBusGpadl *gpadl, *tmp_gpadl; + VMBusChannel *chan; + + QTAILQ_FOREACH_SAFE(gpadl, &vmbus->gpadl_list, link, tmp_gpadl) { + if (gpadl->state == VMGPADL_TORNDOWN) { + continue; + } + vmbus_put_gpadl(gpadl); + } + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + chan->offer_state = VMOFFER_INIT; + } + + hyperv_sint_route_unref(vmbus->sint_route); + vmbus->sint_route = NULL; + vmbus->int_page_gpa = 0; + vmbus->target_vp = (uint32_t)-1; + vmbus->version = 0; + vmbus->state = VMBUS_LISTEN; + vmbus->msg_in_progress = false; +} + +static void handle_initiate_contact(VMBus *vmbus, + vmbus_message_initiate_contact *msg, + uint32_t msglen) +{ + if (msglen < sizeof(*msg)) { + return; + } + + trace_vmbus_initiate_contact(msg->version_requested >> 16, + msg->version_requested & 0xffff, + msg->target_vcpu, msg->monitor_page1, + msg->monitor_page2, msg->interrupt_page); + + /* + * Reset vmbus on INITIATE_CONTACT regardless of its previous state. + * Useful, in particular, with vmbus-aware BIOS which can't shut vmbus down + * before handing over to OS loader. + */ + vmbus_reset_all(vmbus); + + vmbus->target_vp = msg->target_vcpu; + vmbus->version = msg->version_requested; + if (vmbus->version < VMBUS_VERSION_WIN8) { + /* linux passes interrupt page even when it doesn't need it */ + vmbus->int_page_gpa = msg->interrupt_page; + } + vmbus->state = VMBUS_HANDSHAKE; + + if (vmbus_init(vmbus)) { + error_report("failed to init vmbus; aborting"); + vmbus_deinit(vmbus); + return; + } +} + +static void send_handshake(VMBus *vmbus) +{ + struct vmbus_message_version_response msg = { + .header.message_type = VMBUS_MSG_VERSION_RESPONSE, + .version_supported = vmbus_initialized(vmbus), + }; + + post_msg(vmbus, &msg, sizeof(msg)); +} + +static void handle_request_offers(VMBus *vmbus, void *msgdata, uint32_t msglen) +{ + VMBusChannel *chan; + + if (!vmbus_initialized(vmbus)) { + return; + } + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->offer_state == VMOFFER_INIT) { + chan->offer_state = VMOFFER_SENDING; + break; + } + } + + vmbus->state = VMBUS_OFFER; +} + +static void send_offer(VMBus *vmbus) +{ + VMBusChannel *chan; + struct vmbus_message_header alloffers_msg = { + .message_type = VMBUS_MSG_ALLOFFERS_DELIVERED, + }; + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->offer_state == VMOFFER_SENDING) { + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(chan->dev); + /* Hyper-V wants LE GUIDs */ + QemuUUID classid = qemu_uuid_bswap(vdc->classid); + QemuUUID instanceid = qemu_uuid_bswap(chan->dev->instanceid); + struct vmbus_message_offer_channel msg = { + .header.message_type = VMBUS_MSG_OFFERCHANNEL, + .child_relid = chan->id, + .connection_id = chan_connection_id(chan), + .channel_flags = vdc->channel_flags, + .mmio_size_mb = vdc->mmio_size_mb, + .sub_channel_index = vmbus_channel_idx(chan), + .interrupt_flags = VMBUS_OFFER_INTERRUPT_DEDICATED, + }; + + memcpy(msg.type_uuid, &classid, sizeof(classid)); + memcpy(msg.instance_uuid, &instanceid, sizeof(instanceid)); + + trace_vmbus_send_offer(chan->id, chan->dev); + + post_msg(vmbus, &msg, sizeof(msg)); + return; + } + } + + /* no more offers, send terminator message */ + trace_vmbus_terminate_offers(); + post_msg(vmbus, &alloffers_msg, sizeof(alloffers_msg)); +} + +static bool complete_offer(VMBus *vmbus) +{ + VMBusChannel *chan; + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->offer_state == VMOFFER_SENDING) { + chan->offer_state = VMOFFER_SENT; + goto next_offer; + } + } + /* + * no transitioning channels found so this is completing the terminator + * message, and vmbus can move to the next state + */ + return true; + +next_offer: + /* try to mark another channel for offering */ + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->offer_state == VMOFFER_INIT) { + chan->offer_state = VMOFFER_SENDING; + break; + } + } + /* + * if an offer has been sent there are more offers or the terminator yet to + * send, so no state transition for vmbus + */ + return false; +} + + +static void handle_gpadl_header(VMBus *vmbus, vmbus_message_gpadl_header *msg, + uint32_t msglen) +{ + VMBusGpadl *gpadl; + uint32_t num_gfns, i; + + /* must include at least one gpa range */ + if (msglen < sizeof(*msg) + sizeof(msg->range[0]) || + !vmbus_initialized(vmbus)) { + return; + } + + num_gfns = (msg->range_buflen - msg->rangecount * sizeof(msg->range[0])) / + sizeof(msg->range[0].pfn_array[0]); + + trace_vmbus_gpadl_header(msg->gpadl_id, num_gfns); + + /* + * In theory the GPADL_HEADER message can define a GPADL with multiple GPA + * ranges each with arbitrary size and alignment. However in practice only + * single-range page-aligned GPADLs have been observed so just ignore + * anything else and simplify things greatly. + */ + if (msg->rangecount != 1 || msg->range[0].byte_offset || + (msg->range[0].byte_count != (num_gfns << TARGET_PAGE_BITS))) { + return; + } + + /* ignore requests to create already existing GPADLs */ + if (find_gpadl(vmbus, msg->gpadl_id)) { + return; + } + + gpadl = create_gpadl(vmbus, msg->gpadl_id, msg->child_relid, num_gfns); + + for (i = 0; i < num_gfns && + (void *)&msg->range[0].pfn_array[i + 1] <= (void *)msg + msglen; + i++) { + gpadl->gfns[gpadl->seen_gfns++] = msg->range[0].pfn_array[i]; + } + + if (gpadl_full(gpadl)) { + vmbus->state = VMBUS_CREATE_GPADL; + } +} + +static void handle_gpadl_body(VMBus *vmbus, vmbus_message_gpadl_body *msg, + uint32_t msglen) +{ + VMBusGpadl *gpadl; + uint32_t num_gfns_left, i; + + if (msglen < sizeof(*msg) || !vmbus_initialized(vmbus)) { + return; + } + + trace_vmbus_gpadl_body(msg->gpadl_id); + + gpadl = find_gpadl(vmbus, msg->gpadl_id); + if (!gpadl) { + return; + } + + num_gfns_left = gpadl->num_gfns - gpadl->seen_gfns; + assert(num_gfns_left); + + for (i = 0; i < num_gfns_left && + (void *)&msg->pfn_array[i + 1] <= (void *)msg + msglen; i++) { + gpadl->gfns[gpadl->seen_gfns++] = msg->pfn_array[i]; + } + + if (gpadl_full(gpadl)) { + vmbus->state = VMBUS_CREATE_GPADL; + } +} + +static void send_create_gpadl(VMBus *vmbus) +{ + VMBusGpadl *gpadl; + + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + if (gpadl_full(gpadl) && gpadl->state == VMGPADL_INIT) { + struct vmbus_message_gpadl_created msg = { + .header.message_type = VMBUS_MSG_GPADL_CREATED, + .gpadl_id = gpadl->id, + .child_relid = gpadl->child_relid, + }; + + trace_vmbus_gpadl_created(gpadl->id); + post_msg(vmbus, &msg, sizeof(msg)); + return; + } + } + + assert(false); +} + +static bool complete_create_gpadl(VMBus *vmbus) +{ + VMBusGpadl *gpadl; + + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + if (gpadl_full(gpadl) && gpadl->state == VMGPADL_INIT) { + gpadl->state = VMGPADL_ALIVE; + + return true; + } + } + + assert(false); + return false; +} + +static void handle_gpadl_teardown(VMBus *vmbus, + vmbus_message_gpadl_teardown *msg, + uint32_t msglen) +{ + VMBusGpadl *gpadl; + + if (msglen < sizeof(*msg) || !vmbus_initialized(vmbus)) { + return; + } + + trace_vmbus_gpadl_teardown(msg->gpadl_id); + + gpadl = find_gpadl(vmbus, msg->gpadl_id); + if (!gpadl || gpadl->state == VMGPADL_TORNDOWN) { + return; + } + + gpadl->state = VMGPADL_TEARINGDOWN; + vmbus->state = VMBUS_TEARDOWN_GPADL; +} + +static void send_teardown_gpadl(VMBus *vmbus) +{ + VMBusGpadl *gpadl; + + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + if (gpadl->state == VMGPADL_TEARINGDOWN) { + struct vmbus_message_gpadl_torndown msg = { + .header.message_type = VMBUS_MSG_GPADL_TORNDOWN, + .gpadl_id = gpadl->id, + }; + + trace_vmbus_gpadl_torndown(gpadl->id); + post_msg(vmbus, &msg, sizeof(msg)); + return; + } + } + + assert(false); +} + +static bool complete_teardown_gpadl(VMBus *vmbus) +{ + VMBusGpadl *gpadl; + + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + if (gpadl->state == VMGPADL_TEARINGDOWN) { + gpadl->state = VMGPADL_TORNDOWN; + vmbus_put_gpadl(gpadl); + return true; + } + } + + assert(false); + return false; +} + +static void handle_open_channel(VMBus *vmbus, vmbus_message_open_channel *msg, + uint32_t msglen) +{ + VMBusChannel *chan; + + if (msglen < sizeof(*msg) || !vmbus_initialized(vmbus)) { + return; + } + + trace_vmbus_open_channel(msg->child_relid, msg->ring_buffer_gpadl_id, + msg->target_vp); + chan = find_channel(vmbus, msg->child_relid); + if (!chan || chan->state != VMCHAN_INIT) { + return; + } + + chan->ringbuf_gpadl = msg->ring_buffer_gpadl_id; + chan->ringbuf_send_offset = msg->ring_buffer_offset; + chan->target_vp = msg->target_vp; + chan->open_id = msg->open_id; + + open_channel(chan); + + chan->state = VMCHAN_OPENING; + vmbus->state = VMBUS_OPEN_CHANNEL; +} + +static void send_open_channel(VMBus *vmbus) +{ + VMBusChannel *chan; + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->state == VMCHAN_OPENING) { + struct vmbus_message_open_result msg = { + .header.message_type = VMBUS_MSG_OPENCHANNEL_RESULT, + .child_relid = chan->id, + .open_id = chan->open_id, + .status = !vmbus_channel_is_open(chan), + }; + + trace_vmbus_channel_open(chan->id, msg.status); + post_msg(vmbus, &msg, sizeof(msg)); + return; + } + } + + assert(false); +} + +static bool complete_open_channel(VMBus *vmbus) +{ + VMBusChannel *chan; + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (chan->state == VMCHAN_OPENING) { + if (vmbus_channel_is_open(chan)) { + chan->state = VMCHAN_OPEN; + /* + * simulate guest notification of ringbuffer space made + * available, for the channel protocols where the host + * initiates the communication + */ + vmbus_channel_notify_host(chan); + } else { + chan->state = VMCHAN_INIT; + } + return true; + } + } + + assert(false); + return false; +} + +static void vdev_reset_on_close(VMBusDevice *vdev) +{ + uint16_t i; + + for (i = 0; i < vdev->num_channels; i++) { + if (vmbus_channel_is_open(&vdev->channels[i])) { + return; + } + } + + /* all channels closed -- reset device */ + qdev_reset_all(DEVICE(vdev)); +} + +static void handle_close_channel(VMBus *vmbus, vmbus_message_close_channel *msg, + uint32_t msglen) +{ + VMBusChannel *chan; + + if (msglen < sizeof(*msg) || !vmbus_initialized(vmbus)) { + return; + } + + trace_vmbus_close_channel(msg->child_relid); + + chan = find_channel(vmbus, msg->child_relid); + if (!chan) { + return; + } + + close_channel(chan); + chan->state = VMCHAN_INIT; + + vdev_reset_on_close(chan->dev); +} + +static void handle_unload(VMBus *vmbus, void *msg, uint32_t msglen) +{ + vmbus->state = VMBUS_UNLOAD; +} + +static void send_unload(VMBus *vmbus) +{ + vmbus_message_header msg = { + .message_type = VMBUS_MSG_UNLOAD_RESPONSE, + }; + + qemu_mutex_lock(&vmbus->rx_queue_lock); + vmbus->rx_queue_size = 0; + qemu_mutex_unlock(&vmbus->rx_queue_lock); + + post_msg(vmbus, &msg, sizeof(msg)); + return; +} + +static bool complete_unload(VMBus *vmbus) +{ + vmbus_reset_all(vmbus); + return true; +} + +static void process_message(VMBus *vmbus) +{ + struct hyperv_post_message_input *hv_msg; + struct vmbus_message_header *msg; + void *msgdata; + uint32_t msglen; + + qemu_mutex_lock(&vmbus->rx_queue_lock); + + if (!vmbus->rx_queue_size) { + goto unlock; + } + + hv_msg = &vmbus->rx_queue[vmbus->rx_queue_head]; + msglen = hv_msg->payload_size; + if (msglen < sizeof(*msg)) { + goto out; + } + msgdata = hv_msg->payload; + msg = (struct vmbus_message_header *)msgdata; + + trace_vmbus_process_incoming_message(msg->message_type); + + switch (msg->message_type) { + case VMBUS_MSG_INITIATE_CONTACT: + handle_initiate_contact(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_REQUESTOFFERS: + handle_request_offers(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_GPADL_HEADER: + handle_gpadl_header(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_GPADL_BODY: + handle_gpadl_body(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_GPADL_TEARDOWN: + handle_gpadl_teardown(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_OPENCHANNEL: + handle_open_channel(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_CLOSECHANNEL: + handle_close_channel(vmbus, msgdata, msglen); + break; + case VMBUS_MSG_UNLOAD: + handle_unload(vmbus, msgdata, msglen); + break; + default: + error_report("unknown message type %#x", msg->message_type); + break; + } + +out: + vmbus->rx_queue_size--; + vmbus->rx_queue_head++; + vmbus->rx_queue_head %= HV_MSG_QUEUE_LEN; + + vmbus_resched(vmbus); +unlock: + qemu_mutex_unlock(&vmbus->rx_queue_lock); +} + +static const struct { + void (*run)(VMBus *vmbus); + bool (*complete)(VMBus *vmbus); +} state_runner[] = { + [VMBUS_LISTEN] = {process_message, NULL}, + [VMBUS_HANDSHAKE] = {send_handshake, NULL}, + [VMBUS_OFFER] = {send_offer, complete_offer}, + [VMBUS_CREATE_GPADL] = {send_create_gpadl, complete_create_gpadl}, + [VMBUS_TEARDOWN_GPADL] = {send_teardown_gpadl, complete_teardown_gpadl}, + [VMBUS_OPEN_CHANNEL] = {send_open_channel, complete_open_channel}, + [VMBUS_UNLOAD] = {send_unload, complete_unload}, +}; + +static void vmbus_do_run(VMBus *vmbus) +{ + if (vmbus->msg_in_progress) { + return; + } + + assert(vmbus->state < VMBUS_STATE_MAX); + assert(state_runner[vmbus->state].run); + state_runner[vmbus->state].run(vmbus); +} + +static void vmbus_run(void *opaque) +{ + VMBus *vmbus = opaque; + + /* make sure no recursion happens (e.g. due to recursive aio_poll()) */ + if (vmbus->in_progress) { + return; + } + + vmbus->in_progress = true; + /* + * FIXME: if vmbus_resched() is called from within vmbus_do_run(), it + * should go *after* the code that can result in aio_poll; otherwise + * reschedules can be missed. No idea how to enforce that. + */ + vmbus_do_run(vmbus); + vmbus->in_progress = false; +} + +static void vmbus_msg_cb(void *data, int status) +{ + VMBus *vmbus = data; + bool (*complete)(VMBus *vmbus); + + assert(vmbus->msg_in_progress); + + trace_vmbus_msg_cb(status); + + if (status == -EAGAIN) { + goto out; + } + if (status) { + error_report("message delivery fatal failure: %d; aborting vmbus", + status); + vmbus_reset_all(vmbus); + return; + } + + assert(vmbus->state < VMBUS_STATE_MAX); + complete = state_runner[vmbus->state].complete; + if (!complete || complete(vmbus)) { + vmbus->state = VMBUS_LISTEN; + } +out: + vmbus->msg_in_progress = false; + vmbus_resched(vmbus); +} + +static void vmbus_resched(VMBus *vmbus) +{ + aio_bh_schedule_oneshot(qemu_get_aio_context(), vmbus_run, vmbus); +} + +static void vmbus_signal_event(EventNotifier *e) +{ + VMBusChannel *chan; + VMBus *vmbus = container_of(e, VMBus, notifier); + unsigned long *int_map; + hwaddr addr, len; + bool is_dirty = false; + + if (!event_notifier_test_and_clear(e)) { + return; + } + + trace_vmbus_signal_event(); + + if (!vmbus->int_page_gpa) { + return; + } + + addr = vmbus->int_page_gpa + TARGET_PAGE_SIZE / 2; + len = TARGET_PAGE_SIZE / 2; + int_map = cpu_physical_memory_map(addr, &len, 1); + if (len != TARGET_PAGE_SIZE / 2) { + goto unmap; + } + + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + if (bitmap_test_and_clear_atomic(int_map, chan->id, 1)) { + if (!vmbus_channel_is_open(chan)) { + continue; + } + vmbus_channel_notify_host(chan); + is_dirty = true; + } + } + +unmap: + cpu_physical_memory_unmap(int_map, len, 1, is_dirty); +} + +static void vmbus_dev_realize(DeviceState *dev, Error **errp) +{ + VMBusDevice *vdev = VMBUS_DEVICE(dev); + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(vdev); + VMBus *vmbus = VMBUS(qdev_get_parent_bus(dev)); + BusChild *child; + Error *err = NULL; + char idstr[UUID_FMT_LEN + 1]; + + assert(!qemu_uuid_is_null(&vdev->instanceid)); + + /* Check for instance id collision for this class id */ + QTAILQ_FOREACH(child, &BUS(vmbus)->children, sibling) { + VMBusDevice *child_dev = VMBUS_DEVICE(child->child); + + if (child_dev == vdev) { + continue; + } + + if (qemu_uuid_is_equal(&child_dev->instanceid, &vdev->instanceid)) { + qemu_uuid_unparse(&vdev->instanceid, idstr); + error_setg(&err, "duplicate vmbus device instance id %s", idstr); + goto error_out; + } + } + + vdev->dma_as = &address_space_memory; + + create_channels(vmbus, vdev, &err); + if (err) { + goto error_out; + } + + if (vdc->vmdev_realize) { + vdc->vmdev_realize(vdev, &err); + if (err) { + goto err_vdc_realize; + } + } + return; + +err_vdc_realize: + free_channels(vdev); +error_out: + error_propagate(errp, err); +} + +static void vmbus_dev_reset(DeviceState *dev) +{ + uint16_t i; + VMBusDevice *vdev = VMBUS_DEVICE(dev); + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(vdev); + + if (vdev->channels) { + for (i = 0; i < vdev->num_channels; i++) { + VMBusChannel *chan = &vdev->channels[i]; + close_channel(chan); + chan->state = VMCHAN_INIT; + } + } + + if (vdc->vmdev_reset) { + vdc->vmdev_reset(vdev); + } +} + +static void vmbus_dev_unrealize(DeviceState *dev) +{ + VMBusDevice *vdev = VMBUS_DEVICE(dev); + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(vdev); + + if (vdc->vmdev_unrealize) { + vdc->vmdev_unrealize(vdev); + } + free_channels(vdev); +} + +static void vmbus_dev_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *kdev = DEVICE_CLASS(klass); + kdev->bus_type = TYPE_VMBUS; + kdev->realize = vmbus_dev_realize; + kdev->unrealize = vmbus_dev_unrealize; + kdev->reset = vmbus_dev_reset; +} + +static Property vmbus_dev_instanceid = + DEFINE_PROP_UUID("instanceid", VMBusDevice, instanceid); + +static void vmbus_dev_instance_init(Object *obj) +{ + VMBusDevice *vdev = VMBUS_DEVICE(obj); + VMBusDeviceClass *vdc = VMBUS_DEVICE_GET_CLASS(vdev); + + if (!qemu_uuid_is_null(&vdc->instanceid)) { + /* Class wants to only have a single instance with a fixed UUID */ + vdev->instanceid = vdc->instanceid; + } else { + qdev_property_add_static(DEVICE(vdev), &vmbus_dev_instanceid); + } +} + +const VMStateDescription vmstate_vmbus_dev = { + .name = TYPE_VMBUS_DEVICE, + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY(instanceid.data, VMBusDevice, 16), + VMSTATE_UINT16(num_channels, VMBusDevice), + VMSTATE_STRUCT_VARRAY_POINTER_UINT16(channels, VMBusDevice, + num_channels, vmstate_channel, + VMBusChannel), + VMSTATE_END_OF_LIST() + } +}; + +/* vmbus generic device base */ +static const TypeInfo vmbus_dev_type_info = { + .name = TYPE_VMBUS_DEVICE, + .parent = TYPE_DEVICE, + .abstract = true, + .instance_size = sizeof(VMBusDevice), + .class_size = sizeof(VMBusDeviceClass), + .class_init = vmbus_dev_class_init, + .instance_init = vmbus_dev_instance_init, +}; + +static void vmbus_realize(BusState *bus, Error **errp) +{ + int ret = 0; + Error *local_err = NULL; + VMBus *vmbus = VMBUS(bus); + + qemu_mutex_init(&vmbus->rx_queue_lock); + + QTAILQ_INIT(&vmbus->gpadl_list); + QTAILQ_INIT(&vmbus->channel_list); + + ret = hyperv_set_msg_handler(VMBUS_MESSAGE_CONNECTION_ID, + vmbus_recv_message, vmbus); + if (ret != 0) { + error_setg(&local_err, "hyperv set message handler failed: %d", ret); + goto error_out; + } + + ret = event_notifier_init(&vmbus->notifier, 0); + if (ret != 0) { + error_setg(&local_err, "event notifier failed to init with %d", ret); + goto remove_msg_handler; + } + + event_notifier_set_handler(&vmbus->notifier, vmbus_signal_event); + ret = hyperv_set_event_flag_handler(VMBUS_EVENT_CONNECTION_ID, + &vmbus->notifier); + if (ret != 0) { + error_setg(&local_err, "hyperv set event handler failed with %d", ret); + goto clear_event_notifier; + } + + return; + +clear_event_notifier: + event_notifier_cleanup(&vmbus->notifier); +remove_msg_handler: + hyperv_set_msg_handler(VMBUS_MESSAGE_CONNECTION_ID, NULL, NULL); +error_out: + qemu_mutex_destroy(&vmbus->rx_queue_lock); + error_propagate(errp, local_err); +} + +static void vmbus_unrealize(BusState *bus) +{ + VMBus *vmbus = VMBUS(bus); + + hyperv_set_msg_handler(VMBUS_MESSAGE_CONNECTION_ID, NULL, NULL); + hyperv_set_event_flag_handler(VMBUS_EVENT_CONNECTION_ID, NULL); + event_notifier_cleanup(&vmbus->notifier); + + qemu_mutex_destroy(&vmbus->rx_queue_lock); +} + +static void vmbus_reset(BusState *bus) +{ + vmbus_deinit(VMBUS(bus)); +} + +static char *vmbus_get_dev_path(DeviceState *dev) +{ + BusState *bus = qdev_get_parent_bus(dev); + return qdev_get_dev_path(bus->parent); +} + +static char *vmbus_get_fw_dev_path(DeviceState *dev) +{ + VMBusDevice *vdev = VMBUS_DEVICE(dev); + char uuid[UUID_FMT_LEN + 1]; + + qemu_uuid_unparse(&vdev->instanceid, uuid); + return g_strdup_printf("%s@%s", qdev_fw_name(dev), uuid); +} + +static void vmbus_class_init(ObjectClass *klass, void *data) +{ + BusClass *k = BUS_CLASS(klass); + + k->get_dev_path = vmbus_get_dev_path; + k->get_fw_dev_path = vmbus_get_fw_dev_path; + k->realize = vmbus_realize; + k->unrealize = vmbus_unrealize; + k->reset = vmbus_reset; +} + +static int vmbus_pre_load(void *opaque) +{ + VMBusChannel *chan; + VMBus *vmbus = VMBUS(opaque); + + /* + * channel IDs allocated by the source will come in the migration stream + * for each channel, so clean up the ones allocated at realize + */ + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + unregister_chan_id(chan); + } + + return 0; +} +static int vmbus_post_load(void *opaque, int version_id) +{ + int ret; + VMBus *vmbus = VMBUS(opaque); + VMBusGpadl *gpadl; + VMBusChannel *chan; + + ret = vmbus_init(vmbus); + if (ret) { + return ret; + } + + QTAILQ_FOREACH(gpadl, &vmbus->gpadl_list, link) { + gpadl->vmbus = vmbus; + gpadl->refcount = 1; + } + + /* + * reopening channels depends on initialized vmbus so it's done here + * instead of channel_post_load() + */ + QTAILQ_FOREACH(chan, &vmbus->channel_list, link) { + + if (chan->state == VMCHAN_OPENING || chan->state == VMCHAN_OPEN) { + open_channel(chan); + } + + if (chan->state != VMCHAN_OPEN) { + continue; + } + + if (!vmbus_channel_is_open(chan)) { + /* reopen failed, abort loading */ + return -1; + } + + /* resume processing on the guest side if it missed the notification */ + hyperv_sint_route_set_sint(chan->notify_route); + /* ditto on the host side */ + vmbus_channel_notify_host(chan); + } + + vmbus_resched(vmbus); + return 0; +} + +static const VMStateDescription vmstate_post_message_input = { + .name = "vmbus/hyperv_post_message_input", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + /* + * skip connection_id and message_type as they are validated before + * queueing and ignored on dequeueing + */ + VMSTATE_UINT32(payload_size, struct hyperv_post_message_input), + VMSTATE_UINT8_ARRAY(payload, struct hyperv_post_message_input, + HV_MESSAGE_PAYLOAD_SIZE), + VMSTATE_END_OF_LIST() + } +}; + +static bool vmbus_rx_queue_needed(void *opaque) +{ + VMBus *vmbus = VMBUS(opaque); + return vmbus->rx_queue_size; +} + +static const VMStateDescription vmstate_rx_queue = { + .name = "vmbus/rx_queue", + .version_id = 0, + .minimum_version_id = 0, + .needed = vmbus_rx_queue_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT8(rx_queue_head, VMBus), + VMSTATE_UINT8(rx_queue_size, VMBus), + VMSTATE_STRUCT_ARRAY(rx_queue, VMBus, + HV_MSG_QUEUE_LEN, 0, + vmstate_post_message_input, + struct hyperv_post_message_input), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription vmstate_vmbus = { + .name = TYPE_VMBUS, + .version_id = 0, + .minimum_version_id = 0, + .pre_load = vmbus_pre_load, + .post_load = vmbus_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT8(state, VMBus), + VMSTATE_UINT32(version, VMBus), + VMSTATE_UINT32(target_vp, VMBus), + VMSTATE_UINT64(int_page_gpa, VMBus), + VMSTATE_QTAILQ_V(gpadl_list, VMBus, 0, + vmstate_gpadl, VMBusGpadl, link), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription * []) { + &vmstate_rx_queue, + NULL + } +}; + +static const TypeInfo vmbus_type_info = { + .name = TYPE_VMBUS, + .parent = TYPE_BUS, + .instance_size = sizeof(VMBus), + .class_init = vmbus_class_init, +}; + +static void vmbus_bridge_realize(DeviceState *dev, Error **errp) +{ + VMBusBridge *bridge = VMBUS_BRIDGE(dev); + + /* + * here there's at least one vmbus bridge that is being realized, so + * vmbus_bridge_find can only return NULL if it's not unique + */ + if (!vmbus_bridge_find()) { + error_setg(errp, "there can be at most one %s in the system", + TYPE_VMBUS_BRIDGE); + return; + } + + if (!hyperv_is_synic_enabled()) { + error_report("VMBus requires usable Hyper-V SynIC and VP_INDEX"); + return; + } + + bridge->bus = VMBUS(qbus_create(TYPE_VMBUS, dev, "vmbus")); +} + +static char *vmbus_bridge_ofw_unit_address(const SysBusDevice *dev) +{ + /* there can be only one VMBus */ + return g_strdup("0"); +} + +static const VMStateDescription vmstate_vmbus_bridge = { + .name = TYPE_VMBUS_BRIDGE, + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_STRUCT_POINTER(bus, VMBusBridge, vmstate_vmbus, VMBus), + VMSTATE_END_OF_LIST() + }, +}; + +static void vmbus_bridge_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *k = DEVICE_CLASS(klass); + SysBusDeviceClass *sk = SYS_BUS_DEVICE_CLASS(klass); + + k->realize = vmbus_bridge_realize; + k->fw_name = "vmbus"; + sk->explicit_ofw_unit_address = vmbus_bridge_ofw_unit_address; + set_bit(DEVICE_CATEGORY_BRIDGE, k->categories); + k->vmsd = &vmstate_vmbus_bridge; + /* override SysBusDevice's default */ + k->user_creatable = true; +} + +static const TypeInfo vmbus_bridge_type_info = { + .name = TYPE_VMBUS_BRIDGE, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(VMBusBridge), + .class_init = vmbus_bridge_class_init, +}; + +static void vmbus_register_types(void) +{ + type_register_static(&vmbus_bridge_type_info); + type_register_static(&vmbus_dev_type_info); + type_register_static(&vmbus_type_info); +} + +type_init(vmbus_register_types) |