/* * Inter-VM Shared Memory PCI device. * * Author: * Cam Macdonell <cam@cs.ualberta.ca> * * Based On: cirrus_vga.c * Copyright (c) 2004 Fabrice Bellard * Copyright (c) 2004 Makoto Suzuki (suzu) * * and rtl8139.c * Copyright (c) 2006 Igor Kovalenko * * This code is licensed under the GNU GPL v2. * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ #include "hw/hw.h" #include "hw/i386/pc.h" #include "hw/pci/pci.h" #include "hw/pci/msix.h" #include "sysemu/kvm.h" #include "migration/migration.h" #include "qapi/qmp/qerror.h" #include "qemu/event_notifier.h" #include "sysemu/char.h" #include <sys/mman.h> #include <sys/types.h> #define PCI_VENDOR_ID_IVSHMEM PCI_VENDOR_ID_REDHAT_QUMRANET #define PCI_DEVICE_ID_IVSHMEM 0x1110 #define IVSHMEM_IOEVENTFD 0 #define IVSHMEM_MSI 1 #define IVSHMEM_PEER 0 #define IVSHMEM_MASTER 1 #define IVSHMEM_REG_BAR_SIZE 0x100 //#define DEBUG_IVSHMEM #ifdef DEBUG_IVSHMEM #define IVSHMEM_DPRINTF(fmt, ...) \ do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0) #else #define IVSHMEM_DPRINTF(fmt, ...) #endif #define TYPE_IVSHMEM "ivshmem" #define IVSHMEM(obj) \ OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM) typedef struct Peer { int nb_eventfds; EventNotifier *eventfds; } Peer; typedef struct EventfdEntry { PCIDevice *pdev; int vector; } EventfdEntry; typedef struct IVShmemState { /*< private >*/ PCIDevice parent_obj; /*< public >*/ uint32_t intrmask; uint32_t intrstatus; uint32_t doorbell; CharDriverState **eventfd_chr; CharDriverState *server_chr; MemoryRegion ivshmem_mmio; /* We might need to register the BAR before we actually have the memory. * So prepare a container MemoryRegion for the BAR immediately and * add a subregion when we have the memory. */ MemoryRegion bar; MemoryRegion ivshmem; uint64_t ivshmem_size; /* size of shared memory region */ uint32_t ivshmem_attr; uint32_t ivshmem_64bit; int shm_fd; /* shared memory file descriptor */ Peer *peers; int nb_peers; /* how many guests we have space for */ int max_peer; /* maximum numbered peer */ int vm_id; uint32_t vectors; uint32_t features; EventfdEntry *eventfd_table; Error *migration_blocker; char * shmobj; char * sizearg; char * role; int role_val; /* scalar to avoid multiple string comparisons */ } IVShmemState; /* registers for the Inter-VM shared memory device */ enum ivshmem_registers { INTRMASK = 0, INTRSTATUS = 4, IVPOSITION = 8, DOORBELL = 12, }; static inline uint32_t ivshmem_has_feature(IVShmemState *ivs, unsigned int feature) { return (ivs->features & (1 << feature)); } static inline bool is_power_of_two(uint64_t x) { return (x & (x - 1)) == 0; } /* accessing registers - based on rtl8139 */ static void ivshmem_update_irq(IVShmemState *s, int val) { PCIDevice *d = PCI_DEVICE(s); int isr; isr = (s->intrstatus & s->intrmask) & 0xffffffff; /* don't print ISR resets */ if (isr) { IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n", isr ? 1 : 0, s->intrstatus, s->intrmask); } qemu_set_irq(d->irq[0], (isr != 0)); } static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val) { IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val); s->intrmask = val; ivshmem_update_irq(s, val); } static uint32_t ivshmem_IntrMask_read(IVShmemState *s) { uint32_t ret = s->intrmask; IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret); return ret; } static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val) { IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val); s->intrstatus = val; ivshmem_update_irq(s, val); } static uint32_t ivshmem_IntrStatus_read(IVShmemState *s) { uint32_t ret = s->intrstatus; /* reading ISR clears all interrupts */ s->intrstatus = 0; ivshmem_update_irq(s, 0); return ret; } static void ivshmem_io_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) { IVShmemState *s = opaque; uint16_t dest = val >> 16; uint16_t vector = val & 0xff; addr &= 0xfc; IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr); switch (addr) { case INTRMASK: ivshmem_IntrMask_write(s, val); break; case INTRSTATUS: ivshmem_IntrStatus_write(s, val); break; case DOORBELL: /* check that dest VM ID is reasonable */ if (dest > s->max_peer) { IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest); break; } /* check doorbell range */ if (vector < s->peers[dest].nb_eventfds) { IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector); event_notifier_set(&s->peers[dest].eventfds[vector]); } break; default: IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest); } } static uint64_t ivshmem_io_read(void *opaque, hwaddr addr, unsigned size) { IVShmemState *s = opaque; uint32_t ret; switch (addr) { case INTRMASK: ret = ivshmem_IntrMask_read(s); break; case INTRSTATUS: ret = ivshmem_IntrStatus_read(s); break; case IVPOSITION: /* return my VM ID if the memory is mapped */ if (s->shm_fd > 0) { ret = s->vm_id; } else { ret = -1; } break; default: IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr); ret = 0; } return ret; } static const MemoryRegionOps ivshmem_mmio_ops = { .read = ivshmem_io_read, .write = ivshmem_io_write, .endianness = DEVICE_NATIVE_ENDIAN, .impl = { .min_access_size = 4, .max_access_size = 4, }, }; static void ivshmem_receive(void *opaque, const uint8_t *buf, int size) { IVShmemState *s = opaque; ivshmem_IntrStatus_write(s, *buf); IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf); } static int ivshmem_can_receive(void * opaque) { return 8; } static void ivshmem_event(void *opaque, int event) { IVSHMEM_DPRINTF("ivshmem_event %d\n", event); } static void fake_irqfd(void *opaque, const uint8_t *buf, int size) { EventfdEntry *entry = opaque; PCIDevice *pdev = entry->pdev; IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector); msix_notify(pdev, entry->vector); } static CharDriverState* create_eventfd_chr_device(void * opaque, EventNotifier *n, int vector) { /* create a event character device based on the passed eventfd */ IVShmemState *s = opaque; CharDriverState * chr; int eventfd = event_notifier_get_fd(n); chr = qemu_chr_open_eventfd(eventfd); if (chr == NULL) { fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd); exit(-1); } qemu_chr_fe_claim_no_fail(chr); /* if MSI is supported we need multiple interrupts */ if (ivshmem_has_feature(s, IVSHMEM_MSI)) { s->eventfd_table[vector].pdev = PCI_DEVICE(s); s->eventfd_table[vector].vector = vector; qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd, ivshmem_event, &s->eventfd_table[vector]); } else { qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive, ivshmem_event, s); } return chr; } static int check_shm_size(IVShmemState *s, int fd) { /* check that the guest isn't going to try and map more memory than the * the object has allocated return -1 to indicate error */ struct stat buf; fstat(fd, &buf); if (s->ivshmem_size > buf.st_size) { fprintf(stderr, "IVSHMEM ERROR: Requested memory size greater" " than shared object size (%" PRIu64 " > %" PRIu64")\n", s->ivshmem_size, (uint64_t)buf.st_size); return -1; } else { return 0; } } /* create the shared memory BAR when we are not using the server, so we can * create the BAR and map the memory immediately */ static void create_shared_memory_BAR(IVShmemState *s, int fd) { void * ptr; s->shm_fd = fd; ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2", s->ivshmem_size, ptr); vmstate_register_ram(&s->ivshmem, DEVICE(s)); memory_region_add_subregion(&s->bar, 0, &s->ivshmem); /* region for shared memory */ pci_register_bar(PCI_DEVICE(s), 2, s->ivshmem_attr, &s->bar); } static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i) { memory_region_add_eventfd(&s->ivshmem_mmio, DOORBELL, 4, true, (posn << 16) | i, &s->peers[posn].eventfds[i]); } static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i) { memory_region_del_eventfd(&s->ivshmem_mmio, DOORBELL, 4, true, (posn << 16) | i, &s->peers[posn].eventfds[i]); } static void close_guest_eventfds(IVShmemState *s, int posn) { int i, guest_curr_max; if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { return; } guest_curr_max = s->peers[posn].nb_eventfds; memory_region_transaction_begin(); for (i = 0; i < guest_curr_max; i++) { ivshmem_del_eventfd(s, posn, i); } memory_region_transaction_commit(); for (i = 0; i < guest_curr_max; i++) { event_notifier_cleanup(&s->peers[posn].eventfds[i]); } g_free(s->peers[posn].eventfds); s->peers[posn].nb_eventfds = 0; } /* this function increase the dynamic storage need to store data about other * guests */ static void increase_dynamic_storage(IVShmemState *s, int new_min_size) { int j, old_nb_alloc; old_nb_alloc = s->nb_peers; while (new_min_size >= s->nb_peers) s->nb_peers = s->nb_peers * 2; IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers); s->peers = g_realloc(s->peers, s->nb_peers * sizeof(Peer)); /* zero out new pointers */ for (j = old_nb_alloc; j < s->nb_peers; j++) { s->peers[j].eventfds = NULL; s->peers[j].nb_eventfds = 0; } } static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) { IVShmemState *s = opaque; int incoming_fd, tmp_fd; int guest_max_eventfd; long incoming_posn; memcpy(&incoming_posn, buf, sizeof(long)); /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr); IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); /* make sure we have enough space for this guest */ if (incoming_posn >= s->nb_peers) { increase_dynamic_storage(s, incoming_posn); } if (tmp_fd == -1) { /* if posn is positive and unseen before then this is our posn*/ if ((incoming_posn >= 0) && (s->peers[incoming_posn].eventfds == NULL)) { /* receive our posn */ s->vm_id = incoming_posn; return; } else { /* otherwise an fd == -1 means an existing guest has gone away */ IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn); close_guest_eventfds(s, incoming_posn); return; } } /* because of the implementation of get_msgfd, we need a dup */ incoming_fd = dup(tmp_fd); if (incoming_fd == -1) { fprintf(stderr, "could not allocate file descriptor %s\n", strerror(errno)); return; } /* if the position is -1, then it's shared memory region fd */ if (incoming_posn == -1) { void * map_ptr; s->max_peer = 0; if (check_shm_size(s, incoming_fd) == -1) { exit(-1); } /* mmap the region and map into the BAR2 */ map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, incoming_fd, 0); memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2", s->ivshmem_size, map_ptr); vmstate_register_ram(&s->ivshmem, DEVICE(s)); IVSHMEM_DPRINTF("guest h/w addr = %" PRIu64 ", size = %" PRIu64 "\n", s->ivshmem_offset, s->ivshmem_size); memory_region_add_subregion(&s->bar, 0, &s->ivshmem); /* only store the fd if it is successfully mapped */ s->shm_fd = incoming_fd; return; } /* each guest has an array of eventfds, and we keep track of how many * guests for each VM */ guest_max_eventfd = s->peers[incoming_posn].nb_eventfds; if (guest_max_eventfd == 0) { /* one eventfd per MSI vector */ s->peers[incoming_posn].eventfds = g_new(EventNotifier, s->vectors); } /* this is an eventfd for a particular guest VM */ IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn, guest_max_eventfd, incoming_fd); event_notifier_init_fd(&s->peers[incoming_posn].eventfds[guest_max_eventfd], incoming_fd); /* increment count for particular guest */ s->peers[incoming_posn].nb_eventfds++; /* keep track of the maximum VM ID */ if (incoming_posn > s->max_peer) { s->max_peer = incoming_posn; } if (incoming_posn == s->vm_id) { s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s, &s->peers[s->vm_id].eventfds[guest_max_eventfd], guest_max_eventfd); } if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { ivshmem_add_eventfd(s, incoming_posn, guest_max_eventfd); } } /* Select the MSI-X vectors used by device. * ivshmem maps events to vectors statically, so * we just enable all vectors on init and after reset. */ static void ivshmem_use_msix(IVShmemState * s) { PCIDevice *d = PCI_DEVICE(s); int i; if (!msix_present(d)) { return; } for (i = 0; i < s->vectors; i++) { msix_vector_use(d, i); } } static void ivshmem_reset(DeviceState *d) { IVShmemState *s = IVSHMEM(d); s->intrstatus = 0; ivshmem_use_msix(s); } static uint64_t ivshmem_get_size(IVShmemState * s) { uint64_t value; char *ptr; value = strtoull(s->sizearg, &ptr, 10); switch (*ptr) { case 0: case 'M': case 'm': value <<= 20; break; case 'G': case 'g': value <<= 30; break; default: fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg); exit(1); } /* BARs must be a power of 2 */ if (!is_power_of_two(value)) { fprintf(stderr, "ivshmem: size must be power of 2\n"); exit(1); } return value; } static void ivshmem_setup_msi(IVShmemState * s) { if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1)) { IVSHMEM_DPRINTF("msix initialization failed\n"); exit(1); } IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors); /* allocate QEMU char devices for receiving interrupts */ s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry)); ivshmem_use_msix(s); } static void ivshmem_save(QEMUFile* f, void *opaque) { IVShmemState *proxy = opaque; PCIDevice *pci_dev = PCI_DEVICE(proxy); IVSHMEM_DPRINTF("ivshmem_save\n"); pci_device_save(pci_dev, f); if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { msix_save(pci_dev, f); } else { qemu_put_be32(f, proxy->intrstatus); qemu_put_be32(f, proxy->intrmask); } } static int ivshmem_load(QEMUFile* f, void *opaque, int version_id) { IVSHMEM_DPRINTF("ivshmem_load\n"); IVShmemState *proxy = opaque; PCIDevice *pci_dev = PCI_DEVICE(proxy); int ret; if (version_id > 0) { return -EINVAL; } if (proxy->role_val == IVSHMEM_PEER) { fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n"); return -EINVAL; } ret = pci_device_load(pci_dev, f); if (ret) { return ret; } if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { msix_load(pci_dev, f); ivshmem_use_msix(proxy); } else { proxy->intrstatus = qemu_get_be32(f); proxy->intrmask = qemu_get_be32(f); } return 0; } static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address, uint32_t val, int len) { pci_default_write_config(pci_dev, address, val, len); msix_write_config(pci_dev, address, val, len); } static int pci_ivshmem_init(PCIDevice *dev) { IVShmemState *s = IVSHMEM(dev); uint8_t *pci_conf; if (s->sizearg == NULL) s->ivshmem_size = 4 << 20; /* 4 MB default */ else { s->ivshmem_size = ivshmem_get_size(s); } register_savevm(DEVICE(dev), "ivshmem", 0, 0, ivshmem_save, ivshmem_load, dev); /* IRQFD requires MSI */ if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) && !ivshmem_has_feature(s, IVSHMEM_MSI)) { fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n"); exit(1); } /* check that role is reasonable */ if (s->role) { if (strncmp(s->role, "peer", 5) == 0) { s->role_val = IVSHMEM_PEER; } else if (strncmp(s->role, "master", 7) == 0) { s->role_val = IVSHMEM_MASTER; } else { fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n"); exit(1); } } else { s->role_val = IVSHMEM_MASTER; /* default */ } if (s->role_val == IVSHMEM_PEER) { error_set(&s->migration_blocker, QERR_DEVICE_FEATURE_BLOCKS_MIGRATION, "peer mode", "ivshmem"); migrate_add_blocker(s->migration_blocker); } pci_conf = dev->config; pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY; pci_config_set_interrupt_pin(pci_conf, 1); s->shm_fd = 0; memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s, "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE); /* region for registers*/ pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->ivshmem_mmio); memory_region_init(&s->bar, OBJECT(s), "ivshmem-bar2-container", s->ivshmem_size); s->ivshmem_attr = PCI_BASE_ADDRESS_SPACE_MEMORY | PCI_BASE_ADDRESS_MEM_PREFETCH; if (s->ivshmem_64bit) { s->ivshmem_attr |= PCI_BASE_ADDRESS_MEM_TYPE_64; } if ((s->server_chr != NULL) && (strncmp(s->server_chr->filename, "unix:", 5) == 0)) { /* if we get a UNIX socket as the parameter we will talk * to the ivshmem server to receive the memory region */ if (s->shmobj != NULL) { fprintf(stderr, "WARNING: do not specify both 'chardev' " "and 'shm' with ivshmem\n"); } IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n", s->server_chr->filename); if (ivshmem_has_feature(s, IVSHMEM_MSI)) { ivshmem_setup_msi(s); } /* we allocate enough space for 16 guests and grow as needed */ s->nb_peers = 16; s->vm_id = -1; /* allocate/initialize space for interrupt handling */ s->peers = g_malloc0(s->nb_peers * sizeof(Peer)); pci_register_bar(dev, 2, s->ivshmem_attr, &s->bar); s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *)); qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read, ivshmem_event, s); } else { /* just map the file immediately, we're not using a server */ int fd; if (s->shmobj == NULL) { fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n"); exit(1); } IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj); /* try opening with O_EXCL and if it succeeds zero the memory * by truncating to 0 */ if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL, S_IRWXU|S_IRWXG|S_IRWXO)) > 0) { /* truncate file to length PCI device's memory */ if (ftruncate(fd, s->ivshmem_size) != 0) { fprintf(stderr, "ivshmem: could not truncate shared file\n"); } } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR, S_IRWXU|S_IRWXG|S_IRWXO)) < 0) { fprintf(stderr, "ivshmem: could not open shared file\n"); exit(-1); } if (check_shm_size(s, fd) == -1) { exit(-1); } create_shared_memory_BAR(s, fd); } dev->config_write = ivshmem_write_config; return 0; } static void pci_ivshmem_uninit(PCIDevice *dev) { IVShmemState *s = IVSHMEM(dev); if (s->migration_blocker) { migrate_del_blocker(s->migration_blocker); error_free(s->migration_blocker); } memory_region_destroy(&s->ivshmem_mmio); memory_region_del_subregion(&s->bar, &s->ivshmem); vmstate_unregister_ram(&s->ivshmem, DEVICE(dev)); memory_region_destroy(&s->ivshmem); memory_region_destroy(&s->bar); unregister_savevm(DEVICE(dev), "ivshmem", s); } static Property ivshmem_properties[] = { DEFINE_PROP_CHR("chardev", IVShmemState, server_chr), DEFINE_PROP_STRING("size", IVShmemState, sizearg), DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1), DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false), DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true), DEFINE_PROP_STRING("shm", IVShmemState, shmobj), DEFINE_PROP_STRING("role", IVShmemState, role), DEFINE_PROP_UINT32("use64", IVShmemState, ivshmem_64bit, 1), DEFINE_PROP_END_OF_LIST(), }; static void ivshmem_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); PCIDeviceClass *k = PCI_DEVICE_CLASS(klass); k->init = pci_ivshmem_init; k->exit = pci_ivshmem_uninit; k->vendor_id = PCI_VENDOR_ID_IVSHMEM; k->device_id = PCI_DEVICE_ID_IVSHMEM; k->class_id = PCI_CLASS_MEMORY_RAM; dc->reset = ivshmem_reset; dc->props = ivshmem_properties; set_bit(DEVICE_CATEGORY_MISC, dc->categories); } static const TypeInfo ivshmem_info = { .name = TYPE_IVSHMEM, .parent = TYPE_PCI_DEVICE, .instance_size = sizeof(IVShmemState), .class_init = ivshmem_class_init, }; static void ivshmem_register_types(void) { type_register_static(&ivshmem_info); } type_init(ivshmem_register_types)