/* * vfio based subchannel assignment support * * Copyright 2017 IBM Corp. * Copyright 2019 Red Hat, Inc. * * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> * Pierre Morel <pmorel@linux.vnet.ibm.com> * Cornelia Huck <cohuck@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2 or (at * your option) any later version. See the COPYING file in the top-level * directory. */ #include "qemu/osdep.h" #include <linux/vfio.h> #include <linux/vfio_ccw.h> #include <sys/ioctl.h> #include "qapi/error.h" #include "hw/sysbus.h" #include "hw/vfio/vfio.h" #include "hw/vfio/vfio-common.h" #include "hw/s390x/s390-ccw.h" #include "hw/s390x/vfio-ccw.h" #include "hw/qdev-properties.h" #include "hw/s390x/ccw-device.h" #include "exec/address-spaces.h" #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "qemu/module.h" struct VFIOCCWDevice { S390CCWDevice cdev; VFIODevice vdev; uint64_t io_region_size; uint64_t io_region_offset; struct ccw_io_region *io_region; uint64_t async_cmd_region_size; uint64_t async_cmd_region_offset; struct ccw_cmd_region *async_cmd_region; uint64_t schib_region_size; uint64_t schib_region_offset; struct ccw_schib_region *schib_region; uint64_t crw_region_size; uint64_t crw_region_offset; struct ccw_crw_region *crw_region; EventNotifier io_notifier; EventNotifier crw_notifier; bool force_orb_pfch; bool warned_orb_pfch; }; static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch, const char *msg) { warn_report_once_cond(&vcdev->warned_orb_pfch, "vfio-ccw (devno %x.%x.%04x): %s", sch->cssid, sch->ssid, sch->devno, msg); } static void vfio_ccw_compute_needs_reset(VFIODevice *vdev) { vdev->needs_reset = false; } /* * We don't need vfio_hot_reset_multi and vfio_eoi operations for * vfio_ccw device now. */ struct VFIODeviceOps vfio_ccw_ops = { .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset, }; static IOInstEnding vfio_ccw_handle_request(SubchDev *sch) { S390CCWDevice *cdev = sch->driver_data; VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); struct ccw_io_region *region = vcdev->io_region; int ret; if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) { sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH; warn_once_pfch(vcdev, sch, "PFCH flag forced"); } QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB)); QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW)); QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB)); memset(region, 0, sizeof(*region)); memcpy(region->orb_area, &sch->orb, sizeof(ORB)); memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW)); again: ret = pwrite(vcdev->vdev.fd, region, vcdev->io_region_size, vcdev->io_region_offset); if (ret != vcdev->io_region_size) { if (errno == EAGAIN) { goto again; } error_report("vfio-ccw: write I/O region failed with errno=%d", errno); ret = -errno; } else { ret = region->ret_code; } switch (ret) { case 0: return IOINST_CC_EXPECTED; case -EBUSY: return IOINST_CC_BUSY; case -ENODEV: case -EACCES: return IOINST_CC_NOT_OPERATIONAL; case -EFAULT: default: sch_gen_unit_exception(sch); css_inject_io_interrupt(sch); return IOINST_CC_EXPECTED; } } static IOInstEnding vfio_ccw_handle_store(SubchDev *sch) { S390CCWDevice *cdev = sch->driver_data; VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); SCHIB *schib = &sch->curr_status; struct ccw_schib_region *region = vcdev->schib_region; SCHIB *s; int ret; /* schib region not available so nothing else to do */ if (!region) { return IOINST_CC_EXPECTED; } memset(region, 0, sizeof(*region)); ret = pread(vcdev->vdev.fd, region, vcdev->schib_region_size, vcdev->schib_region_offset); if (ret == -1) { /* * Device is probably damaged, but store subchannel does not * have a nonzero cc defined for this scenario. Log an error, * and presume things are otherwise fine. */ error_report("vfio-ccw: store region read failed with errno=%d", errno); return IOINST_CC_EXPECTED; } /* * Selectively copy path-related bits of the SCHIB, * rather than copying the entire struct. */ s = (SCHIB *)region->schib_area; schib->pmcw.pnom = s->pmcw.pnom; schib->pmcw.lpum = s->pmcw.lpum; schib->pmcw.pam = s->pmcw.pam; schib->pmcw.pom = s->pmcw.pom; if (s->scsw.flags & SCSW_FLAGS_MASK_PNO) { schib->scsw.flags |= SCSW_FLAGS_MASK_PNO; } return IOINST_CC_EXPECTED; } static int vfio_ccw_handle_clear(SubchDev *sch) { S390CCWDevice *cdev = sch->driver_data; VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); struct ccw_cmd_region *region = vcdev->async_cmd_region; int ret; if (!vcdev->async_cmd_region) { /* Async command region not available, fall back to emulation */ return -ENOSYS; } memset(region, 0, sizeof(*region)); region->command = VFIO_CCW_ASYNC_CMD_CSCH; again: ret = pwrite(vcdev->vdev.fd, region, vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset); if (ret != vcdev->async_cmd_region_size) { if (errno == EAGAIN) { goto again; } error_report("vfio-ccw: write cmd region failed with errno=%d", errno); ret = -errno; } else { ret = region->ret_code; } switch (ret) { case 0: case -ENODEV: case -EACCES: return 0; case -EFAULT: default: sch_gen_unit_exception(sch); css_inject_io_interrupt(sch); return 0; } } static int vfio_ccw_handle_halt(SubchDev *sch) { S390CCWDevice *cdev = sch->driver_data; VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); struct ccw_cmd_region *region = vcdev->async_cmd_region; int ret; if (!vcdev->async_cmd_region) { /* Async command region not available, fall back to emulation */ return -ENOSYS; } memset(region, 0, sizeof(*region)); region->command = VFIO_CCW_ASYNC_CMD_HSCH; again: ret = pwrite(vcdev->vdev.fd, region, vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset); if (ret != vcdev->async_cmd_region_size) { if (errno == EAGAIN) { goto again; } error_report("vfio-ccw: write cmd region failed with errno=%d", errno); ret = -errno; } else { ret = region->ret_code; } switch (ret) { case 0: case -EBUSY: case -ENODEV: case -EACCES: return 0; case -EFAULT: default: sch_gen_unit_exception(sch); css_inject_io_interrupt(sch); return 0; } } static void vfio_ccw_reset(DeviceState *dev) { CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET); } static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev) { struct ccw_crw_region *region = vcdev->crw_region; CRW crw; int size; /* Keep reading CRWs as long as data is returned */ do { memset(region, 0, sizeof(*region)); size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size, vcdev->crw_region_offset); if (size == -1) { error_report("vfio-ccw: Read crw region failed with errno=%d", errno); break; } if (region->crw == 0) { /* No more CRWs to queue */ break; } memcpy(&crw, ®ion->crw, sizeof(CRW)); css_crw_add_to_queue(crw); } while (1); } static void vfio_ccw_crw_notifier_handler(void *opaque) { VFIOCCWDevice *vcdev = opaque; while (event_notifier_test_and_clear(&vcdev->crw_notifier)) { vfio_ccw_crw_read(vcdev); } } static void vfio_ccw_io_notifier_handler(void *opaque) { VFIOCCWDevice *vcdev = opaque; struct ccw_io_region *region = vcdev->io_region; S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev); CcwDevice *ccw_dev = CCW_DEVICE(cdev); SubchDev *sch = ccw_dev->sch; SCHIB *schib = &sch->curr_status; SCSW s; IRB irb; int size; if (!event_notifier_test_and_clear(&vcdev->io_notifier)) { return; } size = pread(vcdev->vdev.fd, region, vcdev->io_region_size, vcdev->io_region_offset); if (size == -1) { switch (errno) { case ENODEV: /* Generate a deferred cc 3 condition. */ schib->scsw.flags |= SCSW_FLAGS_MASK_CC; schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND); goto read_err; case EFAULT: /* Memory problem, generate channel data check. */ schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK; schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; goto read_err; default: /* Error, generate channel program check. */ schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK; schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; goto read_err; } } else if (size != vcdev->io_region_size) { /* Information transfer error, generate channel-control check. */ schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK; schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; goto read_err; } memcpy(&irb, region->irb_area, sizeof(IRB)); /* Update control block via irb. */ s = schib->scsw; copy_scsw_to_guest(&s, &irb.scsw); schib->scsw = s; /* If a uint check is pending, copy sense data. */ if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) && (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) { memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw)); } read_err: css_inject_io_interrupt(sch); } static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev, unsigned int irq, Error **errp) { VFIODevice *vdev = &vcdev->vdev; struct vfio_irq_info *irq_info; size_t argsz; int fd; EventNotifier *notifier; IOHandler *fd_read; switch (irq) { case VFIO_CCW_IO_IRQ_INDEX: notifier = &vcdev->io_notifier; fd_read = vfio_ccw_io_notifier_handler; break; case VFIO_CCW_CRW_IRQ_INDEX: notifier = &vcdev->crw_notifier; fd_read = vfio_ccw_crw_notifier_handler; break; default: error_setg(errp, "vfio: Unsupported device irq(%d)", irq); return; } if (vdev->num_irqs < irq + 1) { error_setg(errp, "vfio: unexpected number of irqs %u", vdev->num_irqs); return; } argsz = sizeof(*irq_info); irq_info = g_malloc0(argsz); irq_info->index = irq; irq_info->argsz = argsz; if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info) < 0 || irq_info->count < 1) { error_setg_errno(errp, errno, "vfio: Error getting irq info"); goto out_free_info; } if (event_notifier_init(notifier, 0)) { error_setg_errno(errp, errno, "vfio: Unable to init event notifier for irq (%d)", irq); goto out_free_info; } fd = event_notifier_get_fd(notifier); qemu_set_fd_handler(fd, fd_read, NULL, vcdev); if (vfio_set_irq_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) { qemu_set_fd_handler(fd, NULL, NULL, vcdev); event_notifier_cleanup(notifier); } out_free_info: g_free(irq_info); } static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev, unsigned int irq) { Error *err = NULL; EventNotifier *notifier; switch (irq) { case VFIO_CCW_IO_IRQ_INDEX: notifier = &vcdev->io_notifier; break; case VFIO_CCW_CRW_IRQ_INDEX: notifier = &vcdev->crw_notifier; break; default: error_report("vfio: Unsupported device irq(%d)", irq); return; } if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) { error_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name); } qemu_set_fd_handler(event_notifier_get_fd(notifier), NULL, NULL, vcdev); event_notifier_cleanup(notifier); } static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp) { VFIODevice *vdev = &vcdev->vdev; struct vfio_region_info *info; int ret; /* Sanity check device */ if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) { error_setg(errp, "vfio: Um, this isn't a vfio-ccw device"); return; } /* * We always expect at least the I/O region to be present. We also * may have a variable number of regions governed by capabilities. */ if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) { error_setg(errp, "vfio: too few regions (%u), expected at least %u", vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1); return; } ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info); if (ret) { error_setg_errno(errp, -ret, "vfio: Error getting config info"); return; } vcdev->io_region_size = info->size; if (sizeof(*vcdev->io_region) != vcdev->io_region_size) { error_setg(errp, "vfio: Unexpected size of the I/O region"); goto out_err; } vcdev->io_region_offset = info->offset; vcdev->io_region = g_malloc0(info->size); /* check for the optional async command region */ ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW, VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info); if (!ret) { vcdev->async_cmd_region_size = info->size; if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) { error_setg(errp, "vfio: Unexpected size of the async cmd region"); goto out_err; } vcdev->async_cmd_region_offset = info->offset; vcdev->async_cmd_region = g_malloc0(info->size); } ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW, VFIO_REGION_SUBTYPE_CCW_SCHIB, &info); if (!ret) { vcdev->schib_region_size = info->size; if (sizeof(*vcdev->schib_region) != vcdev->schib_region_size) { error_setg(errp, "vfio: Unexpected size of the schib region"); goto out_err; } vcdev->schib_region_offset = info->offset; vcdev->schib_region = g_malloc(info->size); } ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW, VFIO_REGION_SUBTYPE_CCW_CRW, &info); if (!ret) { vcdev->crw_region_size = info->size; if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) { error_setg(errp, "vfio: Unexpected size of the CRW region"); goto out_err; } vcdev->crw_region_offset = info->offset; vcdev->crw_region = g_malloc(info->size); } g_free(info); return; out_err: g_free(vcdev->crw_region); g_free(vcdev->schib_region); g_free(vcdev->async_cmd_region); g_free(vcdev->io_region); g_free(info); return; } static void vfio_ccw_put_region(VFIOCCWDevice *vcdev) { g_free(vcdev->crw_region); g_free(vcdev->schib_region); g_free(vcdev->async_cmd_region); g_free(vcdev->io_region); } static void vfio_ccw_put_device(VFIOCCWDevice *vcdev) { g_free(vcdev->vdev.name); vfio_put_base_device(&vcdev->vdev); } static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev, Error **errp) { char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid, vcdev->cdev.hostid.ssid, vcdev->cdev.hostid.devid); VFIODevice *vbasedev; QLIST_FOREACH(vbasedev, &group->device_list, next) { if (strcmp(vbasedev->name, name) == 0) { error_setg(errp, "vfio: subchannel %s has already been attached", name); goto out_err; } } /* * All vfio-ccw devices are believed to operate in a way compatible with * discarding of memory in RAM blocks, ie. pages pinned in the host are * in the current working set of the guest driver and therefore never * overlap e.g., with pages available to the guest balloon driver. This * needs to be set before vfio_get_device() for vfio common to handle * ram_block_discard_disable(). */ vcdev->vdev.ram_block_discard_allowed = true; if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) { goto out_err; } vcdev->vdev.ops = &vfio_ccw_ops; vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW; vcdev->vdev.name = name; vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj; return; out_err: g_free(name); } static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp) { char *tmp, group_path[PATH_MAX]; ssize_t len; int groupid; tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group", cdev->hostid.cssid, cdev->hostid.ssid, cdev->hostid.devid, cdev->mdevid); len = readlink(tmp, group_path, sizeof(group_path)); g_free(tmp); if (len <= 0 || len >= sizeof(group_path)) { error_setg(errp, "vfio: no iommu_group found"); return NULL; } group_path[len] = 0; if (sscanf(basename(group_path), "%d", &groupid) != 1) { error_setg(errp, "vfio: failed to read %s", group_path); return NULL; } return vfio_get_group(groupid, &address_space_memory, errp); } static void vfio_ccw_realize(DeviceState *dev, Error **errp) { VFIOGroup *group; CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); Error *err = NULL; /* Call the class init function for subchannel. */ if (cdc->realize) { cdc->realize(cdev, vcdev->vdev.sysfsdev, &err); if (err) { goto out_err_propagate; } } group = vfio_ccw_get_group(cdev, &err); if (!group) { goto out_group_err; } vfio_ccw_get_device(group, vcdev, &err); if (err) { goto out_device_err; } vfio_ccw_get_region(vcdev, &err); if (err) { goto out_region_err; } vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err); if (err) { goto out_notifier_err; } if (vcdev->crw_region) { vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err); if (err) { vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX); goto out_notifier_err; } } return; out_notifier_err: vfio_ccw_put_region(vcdev); out_region_err: vfio_ccw_put_device(vcdev); out_device_err: vfio_put_group(group); out_group_err: if (cdc->unrealize) { cdc->unrealize(cdev); } out_err_propagate: error_propagate(errp, err); } static void vfio_ccw_unrealize(DeviceState *dev) { CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); VFIOGroup *group = vcdev->vdev.group; vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX); vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX); vfio_ccw_put_region(vcdev); vfio_ccw_put_device(vcdev); vfio_put_group(group); if (cdc->unrealize) { cdc->unrealize(cdev); } } static Property vfio_ccw_properties[] = { DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev), DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false), DEFINE_PROP_END_OF_LIST(), }; static const VMStateDescription vfio_ccw_vmstate = { .name = "vfio-ccw", .unmigratable = 1, }; static void vfio_ccw_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass); device_class_set_props(dc, vfio_ccw_properties); dc->vmsd = &vfio_ccw_vmstate; dc->desc = "VFIO-based subchannel assignment"; set_bit(DEVICE_CATEGORY_MISC, dc->categories); dc->realize = vfio_ccw_realize; dc->unrealize = vfio_ccw_unrealize; dc->reset = vfio_ccw_reset; cdc->handle_request = vfio_ccw_handle_request; cdc->handle_halt = vfio_ccw_handle_halt; cdc->handle_clear = vfio_ccw_handle_clear; cdc->handle_store = vfio_ccw_handle_store; } static const TypeInfo vfio_ccw_info = { .name = TYPE_VFIO_CCW, .parent = TYPE_S390_CCW, .instance_size = sizeof(VFIOCCWDevice), .class_init = vfio_ccw_class_init, }; static void register_vfio_ccw_type(void) { type_register_static(&vfio_ccw_info); } type_init(register_vfio_ccw_type)