[Qemu-devel] [RFC 4/9] Add MMIO based virtio transport

[Evgeny Voevodin]

From: Peter Maydell <address@hidden>

        Add support for the generic MMIO based virtio transport.

        This patch is a modyfied patch of
        Peter Maydell <address@hidden>. Changes are to have
        virtio-mmio bridge device which provides virtio-mmio bus. To this bus
        virtio-mmio-transport device is connected and in turn provides
        virtio-transport bus. Then virtio backends could be connected to this
        bus.

        Also this patch includes some fixes for bugs spotted by
        Ying-Shiuan Pan <address@hidden>.

Signed-off-by: Evgeny Voevodin <address@hidden>
---
 Makefile.objs    |    1 +
 hw/virtio-mmio.c |  480 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio-mmio.h |   31 ++++
 3 files changed, 512 insertions(+), 0 deletions(-)
 create mode 100644 hw/virtio-mmio.c
 create mode 100644 hw/virtio-mmio.h

diff --git a/Makefile.objs b/Makefile.objs
index 5a648bc..fe95bdd 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -213,6 +213,7 @@ hw-obj-$(CONFIG_VIRTIO) += virtio-console.o
 hw-obj-y += usb/libhw.o
 hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 hw-obj-$(CONFIG_VIRTIO) += virtio-transport.o
+hw-obj-$(CONFIG_VIRTIO) += virtio-mmio.o
 hw-obj-y += fw_cfg.o
 hw-obj-$(CONFIG_PCI) += pci.o pci_bridge.o pci_bridge_dev.o
 hw-obj-$(CONFIG_PCI) += msix.o msi.o
diff --git a/hw/virtio-mmio.c b/hw/virtio-mmio.c
new file mode 100644
index 0000000..932b3f3
--- /dev/null
+++ b/hw/virtio-mmio.c
@@ -0,0 +1,480 @@
+/*
+ * Virtio MMIO bindings
+ *
+ * Copyright (c) 2011 Linaro Limited
+ *
+ * Authors:
+ *  Peter Maydell <address@hidden>
+ *  Evgeny Voevodin <address@hidden>
+ *
+ * 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/>.
+ */
+
+/* TODO:
+ *  * save/load support
+ *  * test net, serial, balloon
+ */
+
+#include "sysbus.h"
+#include "virtio.h"
+#include "virtio-transport.h"
+#include "virtio-blk.h"
+#include "virtio-net.h"
+#include "virtio-serial.h"
+#include "host-utils.h"
+#include "virtio-mmio.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
+
+/* 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' */
+
+#define VIRTIO_MMIO_BRIDGE "virtio-mmio-bridge"
+#define VIRTIO_MMIO_TRANSPORT "virtio-mmio-transport"
+#define VIRTIO_MMIO "virtio-mmio"
+#define VIRTIO_MMIO_BUS "virtio-mmio-bus"
+
+struct BusInfo virtio_mmio_bus_info = {
+    .name = VIRTIO_MMIO_BUS,
+    .size = sizeof(BusState),
+};
+
+enum VIRTIO_MMIO_MAPPINGS {
+    VIRTIO_MMIO_IOMAP,
+    VIRTIO_MMIO_IOMEM,
+};
+
+typedef struct {
+    SysBusDevice busdev;
+    VirtIODevice *vdev;
+    MemoryRegion iomap; /* hold base address */
+    MemoryRegion iomem; /* hold io funcs */
+    MemoryRegion alias;
+    qemu_irq irq;
+    uint32_t int_enable;
+    uint32_t host_features;
+    uint32_t host_features_sel;
+    uint32_t guest_features_sel;
+    uint32_t guest_page_shift;
+} VirtIOMMIOTransportState;
+
+BusState *virtio_mmio_bus_init(void)
+{
+    DeviceState *dev;
+
+    /* Create bridge device */
+    dev = qdev_create(NULL, VIRTIO_MMIO_BRIDGE);
+    qdev_init_nofail(dev);
+
+    return qbus_create(&virtio_mmio_bus_info, dev, virtio_mmio_bus_info.name);
+}
+
+void virtio_mmio_create_transport(BusState *bus, target_phys_addr_t addr,
+        qemu_irq irq)
+{
+    DeviceState *dev;
+    SysBusDevice *busdev;
+
+    dev = qdev_create(bus, VIRTIO_MMIO_TRANSPORT);
+    qdev_init_nofail(dev);
+    busdev = sysbus_from_qdev(dev);
+    sysbus_connect_irq(busdev, 0, irq);
+    sysbus_mmio_map(busdev, VIRTIO_MMIO_IOMAP, addr);
+}
+
+static uint64_t virtio_mmio_read(void *opaque, target_phys_addr_t offset,
+                                 unsigned size)
+{
+    VirtIOMMIOTransportState *transport = (VirtIOMMIOTransportState *)opaque;
+    VirtIODevice *vdev = transport->vdev;
+    DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
+    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 (transport->host_features_sel) {
+            return 0;
+        }
+        return transport->host_features;
+    case VIRTIO_MMIO_QUEUENUMMAX:
+        return VIRTQUEUE_MAX_SIZE;
+    case VIRTIO_MMIO_QUEUEPFN:
+        return virtio_queue_get_addr(vdev, vdev->queue_sel)
+            >> transport->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, target_phys_addr_t offset,
+                              uint64_t value, unsigned size)
+{
+    VirtIOMMIOTransportState *transport = (VirtIOMMIOTransportState *)opaque;
+    VirtIODevice *vdev = transport->vdev;
+    DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
+            (int)offset, value);
+    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:
+        transport->host_features_sel = value;
+        break;
+    case VIRTIO_MMIO_GUESTFEATURES:
+        if (!transport->guest_features_sel) {
+            virtio_set_features(vdev, value);
+        }
+        break;
+    case VIRTIO_MMIO_GUESTFEATURESSEL:
+        transport->guest_features_sel = value;
+        break;
+    case VIRTIO_MMIO_GUESTPAGESIZE:
+        transport->guest_page_shift = ctz32(value);
+        if (transport->guest_page_shift > 31) {
+            transport->guest_page_shift = 0;
+        }
+        DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
+                transport->guest_page_shift);
+        break;
+    case VIRTIO_MMIO_QUEUESEL:
+        if (value < VIRTIO_PCI_QUEUE_MAX) {
+            vdev->queue_sel = value;
+        }
+        break;
+    case VIRTIO_MMIO_QUEUENUM:
+        DPRINTF("mmio_queue write %d max %d\n", (int)value, 
VIRTQUEUE_MAX_SIZE);
+        if (value <= VIRTQUEUE_MAX_SIZE) {
+            DPRINTF("calling virtio_queue_set_num\n");
+            virtio_queue_set_num(vdev, vdev->queue_sel, value);
+        }
+        break;
+    case VIRTIO_MMIO_QUEUEALIGN:
+        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 << transport->guest_page_shift);
+        }
+        break;
+    case VIRTIO_MMIO_QUEUENOTIFY:
+        if (value < VIRTIO_PCI_QUEUE_MAX) {
+            virtio_queue_notify(vdev, value);
+        }
+        break;
+    case VIRTIO_MMIO_INTERRUPTACK:
+        vdev->isr &= ~value;
+        virtio_update_irq(vdev);
+        break;
+    case VIRTIO_MMIO_STATUS:
+        virtio_set_status(vdev, value & 0xff);
+        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(void *opaque, uint16_t vector)
+{
+    VirtIOMMIOTransportState *transport = opaque;
+    int level = (transport->vdev->isr != 0);
+    DPRINTF("virtio_mmio setting IRQ %d\n", level);
+    qemu_set_irq(transport->irq, level);
+}
+
+static unsigned int virtio_mmio_get_features(void *opaque)
+{
+    VirtIOMMIOTransportState *transport = opaque;
+    return transport->host_features;
+}
+
+static int virtio_mmio_load_config(void *opaque, QEMUFile *f)
+{
+    VirtIOMMIOTransportState *transport = opaque;
+    transport->int_enable = qemu_get_be32(f);
+    transport->host_features = qemu_get_be32(f);
+    transport->host_features_sel = qemu_get_be32(f);
+    transport->guest_features_sel = qemu_get_be32(f);
+    transport->guest_page_shift = qemu_get_be32(f);
+    return 0;
+}
+
+static void virtio_mmio_save_config(void *opaque, QEMUFile *f)
+{
+    VirtIOMMIOTransportState *transport = opaque;
+    qemu_put_be32(f, transport->int_enable);
+    qemu_put_be32(f, transport->host_features);
+    qemu_put_be32(f, transport->host_features_sel);
+    qemu_put_be32(f, transport->guest_features_sel);
+    qemu_put_be32(f, transport->guest_page_shift);
+}
+
+static VirtIOBindings virtio_mmio_bindings = {
+    .notify = virtio_mmio_update_irq,
+    .get_features = virtio_mmio_get_features,
+    .save_config = virtio_mmio_save_config,
+    .load_config = virtio_mmio_load_config,
+};
+
+static void virtio_mmio_attach_to_transport(DeviceState *dev)
+{
+    DeviceState *transport_dev = qdev_get_parent_bus(dev)->parent;
+    SysBusDevice *transport_sysbus = sysbus_from_qdev(transport_dev);
+    VirtIOMMIOTransportState *transport =
+            FROM_SYSBUS(VirtIOMMIOTransportState, transport_sysbus);
+
+    /* Create alias and add it as subregion to transport iomem */
+    memory_region_init_alias(&transport->alias,
+                             "virtio-mmio-alias",
+                             &transport->iomem,
+                             0,
+                             0x1000);
+    /* add alias as subregion to transport iomap */
+    memory_region_add_subregion(&transport->iomap,
+                                0,
+                                &transport->alias);
+}
+
+static int virtio_init_mmio_transport(DeviceState *dev, VirtIODevice *vdev)
+{
+    DeviceState *transport_dev = qdev_get_parent_bus(dev)->parent;
+    SysBusDevice *transport_sysbus = sysbus_from_qdev(transport_dev);
+    VirtIOMMIOTransportState *transport =
+            FROM_SYSBUS(VirtIOMMIOTransportState, transport_sysbus);
+
+    transport->vdev = vdev;
+    transport->vdev->nvectors = 0;
+    sysbus_init_irq(&transport->busdev, &transport->irq);
+    memory_region_init_io(&transport->iomem, &virtio_mem_ops, transport,
+                          "virtio-mmio", 0x1000);
+    sysbus_init_mmio(&transport->busdev, &transport->iomem);
+    virtio_bind_device(vdev, &virtio_mmio_bindings, transport);
+    transport->host_features |= (0x1 << VIRTIO_F_NOTIFY_ON_EMPTY);
+    transport->host_features =
+            vdev->get_features(vdev, transport->host_features);
+
+    virtio_mmio_attach_to_transport(dev);
+    return 0;
+}
+
+static void virtio_mmio_transport_handler(void *opaque, int irq, int level)
+{
+    VirtIOMMIOTransportState *s = (VirtIOMMIOTransportState *)opaque;
+
+    qemu_set_irq(s->irq, level);
+
+    return;
+}
+
+static int virtio_mmio_transport_device_init(SysBusDevice *busdev)
+{
+    VirtIOMMIOTransportState *s =
+            DO_UPCAST(VirtIOMMIOTransportState, busdev, busdev);
+    BusState *mmio_bus = qdev_get_parent_bus(&busdev->qdev);
+    BusState *transport_bus;
+    VirtIOTransportBusState *virtio_transport_bus;
+    DeviceState *dev;
+    char *buf;
+    int len;
+    uint32_t i = 0;
+
+    /* Count siblings */
+    QTAILQ_FOREACH(dev, &mmio_bus->children, sibling) {
+        i++;
+    }
+
+    len = strlen(VIRTIO_MMIO) + 16;
+    buf = g_malloc(len);
+    snprintf(buf, len, "%s.%d", VIRTIO_MMIO, i - 1);
+    transport_bus = qbus_create(&virtio_transport_bus_info, &busdev->qdev, 
buf);
+
+    /* Populate mmio init transport function */
+    virtio_transport_bus =
+            DO_UPCAST(VirtIOTransportBusState, bus, transport_bus);
+    virtio_transport_bus->init_fn = virtio_init_mmio_transport;
+
+    qdev_init_gpio_in(&s->busdev.qdev, virtio_mmio_transport_handler, 1);
+
+    sysbus_init_irq(busdev, &s->irq);
+    memory_region_init(&s->iomap, "virtio-mmio-bridge", 0x1000);
+    sysbus_init_mmio(busdev, &s->iomap);
+    return 0;
+}
+
+static void virtio_mmio_reset(DeviceState *d)
+{
+    VirtIOMMIOTransportState *transport =
+            FROM_SYSBUS(VirtIOMMIOTransportState, sysbus_from_qdev(d));
+    if (transport->vdev) {
+        virtio_reset(transport->vdev);
+    }
+}
+
+static void virtio_mmio_transport_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    k->init = virtio_mmio_transport_device_init;
+    dc->reset = virtio_mmio_reset;
+}
+
+static TypeInfo virtio_mmio_transport_info = {
+    .name = VIRTIO_MMIO_TRANSPORT,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(VirtIOMMIOTransportState),
+    .class_init = virtio_mmio_transport_class_init,
+};
+
+/******************** VirtIOMMIO Bus Bridge Device **********************/
+/* Only required to have the virtio-mmio bus as child in the system bus.
+ * Borrowed from s390. */
+
+static int virtio_mmio_bridge_init(SysBusDevice *dev)
+{
+    /* nothing */
+    return 0;
+}
+
+static void virtio_mmio_bridge_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = virtio_mmio_bridge_init;
+    dc->no_user = 1;
+}
+
+static TypeInfo virtio_mmio_bridge_info = {
+    .name          = VIRTIO_MMIO_BRIDGE,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SysBusDevice),
+    .class_init    = virtio_mmio_bridge_class_init,
+};
+
+static void virtio_mmio_register_types(void)
+{
+    type_register_static(&virtio_mmio_bridge_info);
+    type_register_static(&virtio_mmio_transport_info);
+}
+
+type_init(virtio_mmio_register_types)
diff --git a/hw/virtio-mmio.h b/hw/virtio-mmio.h
new file mode 100644
index 0000000..9a08371
--- /dev/null
+++ b/hw/virtio-mmio.h
@@ -0,0 +1,31 @@
+/*
+ * Virtio MMIO header
+ *
+ * Copyright (c) 2011 - 2012 Samsung Electronics Co., Ltd.
+ *
+ * Author:
+ *  Evgeny Voevodin <address@hidden>
+ *
+ * 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/>.
+ */
+
+#ifndef VIRTIO_MMIO_H_
+#define VIRTIO_MMIO_H_
+
+#include "sysbus.h"
+
+BusState *virtio_mmio_bus_init(void);
+void virtio_mmio_create_transport(BusState *bus, target_phys_addr_t addr,
+        qemu_irq irq);
+
+#endif /* VIRTIO_MMIO_H_ */
-- 
1.7.5.4