--- /dev/null
+/*
+ * 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)
Code Review / kvmfornfv.git / blobdiff