diff options
Diffstat (limited to 'qemu/hw/virtio/virtio-mmio.c')
| -rw-r--r-- | qemu/hw/virtio/virtio-mmio.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/qemu/hw/virtio/virtio-mmio.c b/qemu/hw/virtio/virtio-mmio.c new file mode 100644 index 000000000..18660b07b --- /dev/null +++ b/qemu/hw/virtio/virtio-mmio.c @@ -0,0 +1,579 @@ +/* + * Virtio MMIO bindings + * + * Copyright (c) 2011 Linaro Limited + * + * Author: + * Peter Maydell <peter.maydell@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "hw/sysbus.h" +#include "hw/virtio/virtio.h" +#include "qemu/host-utils.h" +#include "sysemu/kvm.h" +#include "hw/virtio/virtio-bus.h" +#include "qemu/error-report.h" + +/* #define DEBUG_VIRTIO_MMIO */ + +#ifdef DEBUG_VIRTIO_MMIO + +#define DPRINTF(fmt, ...) \ +do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) do {} while (0) +#endif + +/* QOM macros */ +/* virtio-mmio-bus */ +#define TYPE_VIRTIO_MMIO_BUS "virtio-mmio-bus" +#define VIRTIO_MMIO_BUS(obj) \ + OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_MMIO_BUS) +#define VIRTIO_MMIO_BUS_GET_CLASS(obj) \ + OBJECT_GET_CLASS(VirtioBusClass, (obj), TYPE_VIRTIO_MMIO_BUS) +#define VIRTIO_MMIO_BUS_CLASS(klass) \ + OBJECT_CLASS_CHECK(VirtioBusClass, (klass), TYPE_VIRTIO_MMIO_BUS) + +/* virtio-mmio */ +#define TYPE_VIRTIO_MMIO "virtio-mmio" +#define VIRTIO_MMIO(obj) \ + OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO) + +/* Memory mapped register offsets */ +#define VIRTIO_MMIO_MAGIC 0x0 +#define VIRTIO_MMIO_VERSION 0x4 +#define VIRTIO_MMIO_DEVICEID 0x8 +#define VIRTIO_MMIO_VENDORID 0xc +#define VIRTIO_MMIO_HOSTFEATURES 0x10 +#define VIRTIO_MMIO_HOSTFEATURESSEL 0x14 +#define VIRTIO_MMIO_GUESTFEATURES 0x20 +#define VIRTIO_MMIO_GUESTFEATURESSEL 0x24 +#define VIRTIO_MMIO_GUESTPAGESIZE 0x28 +#define VIRTIO_MMIO_QUEUESEL 0x30 +#define VIRTIO_MMIO_QUEUENUMMAX 0x34 +#define VIRTIO_MMIO_QUEUENUM 0x38 +#define VIRTIO_MMIO_QUEUEALIGN 0x3c +#define VIRTIO_MMIO_QUEUEPFN 0x40 +#define VIRTIO_MMIO_QUEUENOTIFY 0x50 +#define VIRTIO_MMIO_INTERRUPTSTATUS 0x60 +#define VIRTIO_MMIO_INTERRUPTACK 0x64 +#define VIRTIO_MMIO_STATUS 0x70 +/* Device specific config space starts here */ +#define VIRTIO_MMIO_CONFIG 0x100 + +#define VIRT_MAGIC 0x74726976 /* 'virt' */ +#define VIRT_VERSION 1 +#define VIRT_VENDOR 0x554D4551 /* 'QEMU' */ + +typedef struct { + /* Generic */ + SysBusDevice parent_obj; + MemoryRegion iomem; + qemu_irq irq; + /* Guest accessible state needing migration and reset */ + uint32_t host_features_sel; + uint32_t guest_features_sel; + uint32_t guest_page_shift; + /* virtio-bus */ + VirtioBusState bus; + bool ioeventfd_disabled; + bool ioeventfd_started; +} VirtIOMMIOProxy; + +static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy, + int n, bool assign, + bool set_handler) +{ + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + VirtQueue *vq = virtio_get_queue(vdev, n); + EventNotifier *notifier = virtio_queue_get_host_notifier(vq); + int r = 0; + + if (assign) { + r = event_notifier_init(notifier, 1); + if (r < 0) { + error_report("%s: unable to init event notifier: %d", + __func__, r); + return r; + } + virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler); + memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4, + true, n, notifier); + } else { + memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4, + true, n, notifier); + virtio_queue_set_host_notifier_fd_handler(vq, false, false); + event_notifier_cleanup(notifier); + } + return r; +} + +static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy) +{ + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + int n, r; + + if (!kvm_eventfds_enabled() || + proxy->ioeventfd_disabled || + proxy->ioeventfd_started) { + return; + } + + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + + r = virtio_mmio_set_host_notifier_internal(proxy, n, true, true); + if (r < 0) { + goto assign_error; + } + } + proxy->ioeventfd_started = true; + return; + +assign_error: + while (--n >= 0) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + + r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false); + assert(r >= 0); + } + proxy->ioeventfd_started = false; + error_report("%s: failed. Fallback to a userspace (slower).", __func__); +} + +static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy) +{ + int r; + int n; + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + + if (!proxy->ioeventfd_started) { + return; + } + + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + + r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false); + assert(r >= 0); + } + proxy->ioeventfd_started = false; +} + +static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size) +{ + VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque; + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + + DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset); + + if (!vdev) { + /* If no backend is present, we treat most registers as + * read-as-zero, except for the magic number, version and + * vendor ID. This is not strictly sanctioned by the virtio + * spec, but it allows us to provide transports with no backend + * plugged in which don't confuse Linux's virtio code: the + * probe won't complain about the bad magic number, but the + * device ID of zero means no backend will claim it. + */ + switch (offset) { + case VIRTIO_MMIO_MAGIC: + return VIRT_MAGIC; + case VIRTIO_MMIO_VERSION: + return VIRT_VERSION; + case VIRTIO_MMIO_VENDORID: + return VIRT_VENDOR; + default: + return 0; + } + } + + if (offset >= VIRTIO_MMIO_CONFIG) { + offset -= VIRTIO_MMIO_CONFIG; + switch (size) { + case 1: + return virtio_config_readb(vdev, offset); + case 2: + return virtio_config_readw(vdev, offset); + case 4: + return virtio_config_readl(vdev, offset); + default: + abort(); + } + } + if (size != 4) { + DPRINTF("wrong size access to register!\n"); + return 0; + } + switch (offset) { + case VIRTIO_MMIO_MAGIC: + return VIRT_MAGIC; + case VIRTIO_MMIO_VERSION: + return VIRT_VERSION; + case VIRTIO_MMIO_DEVICEID: + return vdev->device_id; + case VIRTIO_MMIO_VENDORID: + return VIRT_VENDOR; + case VIRTIO_MMIO_HOSTFEATURES: + if (proxy->host_features_sel) { + return 0; + } + return vdev->host_features; + case VIRTIO_MMIO_QUEUENUMMAX: + if (!virtio_queue_get_num(vdev, vdev->queue_sel)) { + return 0; + } + return VIRTQUEUE_MAX_SIZE; + case VIRTIO_MMIO_QUEUEPFN: + return virtio_queue_get_addr(vdev, vdev->queue_sel) + >> proxy->guest_page_shift; + case VIRTIO_MMIO_INTERRUPTSTATUS: + return vdev->isr; + case VIRTIO_MMIO_STATUS: + return vdev->status; + case VIRTIO_MMIO_HOSTFEATURESSEL: + case VIRTIO_MMIO_GUESTFEATURES: + case VIRTIO_MMIO_GUESTFEATURESSEL: + case VIRTIO_MMIO_GUESTPAGESIZE: + case VIRTIO_MMIO_QUEUESEL: + case VIRTIO_MMIO_QUEUENUM: + case VIRTIO_MMIO_QUEUEALIGN: + case VIRTIO_MMIO_QUEUENOTIFY: + case VIRTIO_MMIO_INTERRUPTACK: + DPRINTF("read of write-only register\n"); + return 0; + default: + DPRINTF("bad register offset\n"); + return 0; + } + return 0; +} + +static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque; + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + + DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n", + (int)offset, value); + + if (!vdev) { + /* If no backend is present, we just make all registers + * write-ignored. This allows us to provide transports with + * no backend plugged in. + */ + return; + } + + if (offset >= VIRTIO_MMIO_CONFIG) { + offset -= VIRTIO_MMIO_CONFIG; + switch (size) { + case 1: + virtio_config_writeb(vdev, offset, value); + break; + case 2: + virtio_config_writew(vdev, offset, value); + break; + case 4: + virtio_config_writel(vdev, offset, value); + break; + default: + abort(); + } + return; + } + if (size != 4) { + DPRINTF("wrong size access to register!\n"); + return; + } + switch (offset) { + case VIRTIO_MMIO_HOSTFEATURESSEL: + proxy->host_features_sel = value; + break; + case VIRTIO_MMIO_GUESTFEATURES: + if (!proxy->guest_features_sel) { + virtio_set_features(vdev, value); + } + break; + case VIRTIO_MMIO_GUESTFEATURESSEL: + proxy->guest_features_sel = value; + break; + case VIRTIO_MMIO_GUESTPAGESIZE: + proxy->guest_page_shift = ctz32(value); + if (proxy->guest_page_shift > 31) { + proxy->guest_page_shift = 0; + } + DPRINTF("guest page size %" PRIx64 " shift %d\n", value, + proxy->guest_page_shift); + break; + case VIRTIO_MMIO_QUEUESEL: + if (value < VIRTIO_QUEUE_MAX) { + vdev->queue_sel = value; + } + break; + case VIRTIO_MMIO_QUEUENUM: + DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE); + virtio_queue_set_num(vdev, vdev->queue_sel, value); + /* Note: only call this function for legacy devices */ + virtio_queue_update_rings(vdev, vdev->queue_sel); + break; + case VIRTIO_MMIO_QUEUEALIGN: + /* Note: this is only valid for legacy devices */ + virtio_queue_set_align(vdev, vdev->queue_sel, value); + break; + case VIRTIO_MMIO_QUEUEPFN: + if (value == 0) { + virtio_reset(vdev); + } else { + virtio_queue_set_addr(vdev, vdev->queue_sel, + value << proxy->guest_page_shift); + } + break; + case VIRTIO_MMIO_QUEUENOTIFY: + if (value < VIRTIO_QUEUE_MAX) { + virtio_queue_notify(vdev, value); + } + break; + case VIRTIO_MMIO_INTERRUPTACK: + vdev->isr &= ~value; + virtio_update_irq(vdev); + break; + case VIRTIO_MMIO_STATUS: + if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) { + virtio_mmio_stop_ioeventfd(proxy); + } + + virtio_set_status(vdev, value & 0xff); + + if (value & VIRTIO_CONFIG_S_DRIVER_OK) { + virtio_mmio_start_ioeventfd(proxy); + } + + if (vdev->status == 0) { + virtio_reset(vdev); + } + break; + case VIRTIO_MMIO_MAGIC: + case VIRTIO_MMIO_VERSION: + case VIRTIO_MMIO_DEVICEID: + case VIRTIO_MMIO_VENDORID: + case VIRTIO_MMIO_HOSTFEATURES: + case VIRTIO_MMIO_QUEUENUMMAX: + case VIRTIO_MMIO_INTERRUPTSTATUS: + DPRINTF("write to readonly register\n"); + break; + + default: + DPRINTF("bad register offset\n"); + } +} + +static const MemoryRegionOps virtio_mem_ops = { + .read = virtio_mmio_read, + .write = virtio_mmio_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + int level; + + if (!vdev) { + return; + } + level = (vdev->isr != 0); + DPRINTF("virtio_mmio setting IRQ %d\n", level); + qemu_set_irq(proxy->irq, level); +} + +static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); + + proxy->host_features_sel = qemu_get_be32(f); + proxy->guest_features_sel = qemu_get_be32(f); + proxy->guest_page_shift = qemu_get_be32(f); + return 0; +} + +static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); + + qemu_put_be32(f, proxy->host_features_sel); + qemu_put_be32(f, proxy->guest_features_sel); + qemu_put_be32(f, proxy->guest_page_shift); +} + +static void virtio_mmio_reset(DeviceState *d) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); + + virtio_mmio_stop_ioeventfd(proxy); + virtio_bus_reset(&proxy->bus); + proxy->host_features_sel = 0; + proxy->guest_features_sel = 0; + proxy->guest_page_shift = 0; +} + +static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign, + bool with_irqfd) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); + VirtQueue *vq = virtio_get_queue(vdev, n); + EventNotifier *notifier = virtio_queue_get_guest_notifier(vq); + + if (assign) { + int r = event_notifier_init(notifier, 0); + if (r < 0) { + return r; + } + virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd); + } else { + virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd); + event_notifier_cleanup(notifier); + } + + if (vdc->guest_notifier_mask) { + vdc->guest_notifier_mask(vdev, n, !assign); + } + + return 0; +} + +static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs, + bool assign) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); + /* TODO: need to check if kvm-arm supports irqfd */ + bool with_irqfd = false; + int r, n; + + nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX); + + for (n = 0; n < nvqs; n++) { + if (!virtio_queue_get_num(vdev, n)) { + break; + } + + r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd); + if (r < 0) { + goto assign_error; + } + } + + return 0; + +assign_error: + /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */ + assert(assign); + while (--n >= 0) { + virtio_mmio_set_guest_notifier(d, n, !assign, false); + } + return r; +} + +static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n, + bool assign) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); + + /* Stop using ioeventfd for virtqueue kick if the device starts using host + * notifiers. This makes it easy to avoid stepping on each others' toes. + */ + proxy->ioeventfd_disabled = assign; + if (assign) { + virtio_mmio_stop_ioeventfd(proxy); + } + /* We don't need to start here: it's not needed because backend + * currently only stops on status change away from ok, + * reset, vmstop and such. If we do add code to start here, + * need to check vmstate, device state etc. */ + return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false); +} + +/* virtio-mmio device */ + +static void virtio_mmio_realizefn(DeviceState *d, Error **errp) +{ + VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); + SysBusDevice *sbd = SYS_BUS_DEVICE(d); + + qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS, + d, NULL); + sysbus_init_irq(sbd, &proxy->irq); + memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy, + TYPE_VIRTIO_MMIO, 0x200); + sysbus_init_mmio(sbd, &proxy->iomem); +} + +static void virtio_mmio_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = virtio_mmio_realizefn; + dc->reset = virtio_mmio_reset; + set_bit(DEVICE_CATEGORY_MISC, dc->categories); +} + +static const TypeInfo virtio_mmio_info = { + .name = TYPE_VIRTIO_MMIO, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(VirtIOMMIOProxy), + .class_init = virtio_mmio_class_init, +}; + +/* virtio-mmio-bus. */ + +static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data) +{ + BusClass *bus_class = BUS_CLASS(klass); + VirtioBusClass *k = VIRTIO_BUS_CLASS(klass); + + k->notify = virtio_mmio_update_irq; + k->save_config = virtio_mmio_save_config; + k->load_config = virtio_mmio_load_config; + k->set_host_notifier = virtio_mmio_set_host_notifier; + k->set_guest_notifiers = virtio_mmio_set_guest_notifiers; + k->has_variable_vring_alignment = true; + bus_class->max_dev = 1; +} + +static const TypeInfo virtio_mmio_bus_info = { + .name = TYPE_VIRTIO_MMIO_BUS, + .parent = TYPE_VIRTIO_BUS, + .instance_size = sizeof(VirtioBusState), + .class_init = virtio_mmio_bus_class_init, +}; + +static void virtio_mmio_register_types(void) +{ + type_register_static(&virtio_mmio_bus_info); + type_register_static(&virtio_mmio_info); +} + +type_init(virtio_mmio_register_types) |