Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 154 insertions, 0 deletions

diff --git a/hw/i386/xen/xen_pvdevice.c b/hw/i386/xen/xen_pvdevice.c
new file mode 100644
index 000000000..1ea95fa60
--- /dev/null
+++ b/hw/i386/xen/xen_pvdevice.c
@@ -0,0 +1,154 @@
+/* Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms,
+ * with or without modification, are permitted provided
+ * that the following conditions are met:
+ *
+ * *   Redistributions of source code must retain the above
+ *     copyright notice, this list of conditions and the
+ *     following disclaimer.
+ * *   Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the
+ *     following disclaimer in the documentation and/or other
+ *     materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "hw/pci/pci.h"
+#include "hw/qdev-properties.h"
+#include "migration/vmstate.h"
+#include "trace.h"
+#include "qom/object.h"
+
+#define TYPE_XEN_PV_DEVICE  "xen-pvdevice"
+
+OBJECT_DECLARE_SIMPLE_TYPE(XenPVDevice, XEN_PV_DEVICE)
+
+struct XenPVDevice {
+    /*< private >*/
+    PCIDevice       parent_obj;
+    /*< public >*/
+    uint16_t        vendor_id;
+    uint16_t        device_id;
+    uint8_t         revision;
+    uint32_t        size;
+    MemoryRegion    mmio;
+};
+
+static uint64_t xen_pv_mmio_read(void *opaque, hwaddr addr,
+                                 unsigned size)
+{
+    trace_xen_pv_mmio_read(addr);
+
+    return ~(uint64_t)0;
+}
+
+static void xen_pv_mmio_write(void *opaque, hwaddr addr,
+                              uint64_t val, unsigned size)
+{
+    trace_xen_pv_mmio_write(addr);
+}
+
+static const MemoryRegionOps xen_pv_mmio_ops = {
+    .read = &xen_pv_mmio_read,
+    .write = &xen_pv_mmio_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_xen_pvdevice = {
+    .name = "xen-pvdevice",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_PCI_DEVICE(parent_obj, XenPVDevice),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void xen_pv_realize(PCIDevice *pci_dev, Error **errp)
+{
+    XenPVDevice *d = XEN_PV_DEVICE(pci_dev);
+    uint8_t *pci_conf;
+
+    /* device-id property must always be supplied */
+    if (d->device_id == 0xffff) {
+        error_setg(errp, "Device ID invalid, it must always be supplied");
+        return;
+    }
+
+    pci_conf = pci_dev->config;
+
+    pci_set_word(pci_conf + PCI_VENDOR_ID, d->vendor_id);
+    pci_set_word(pci_conf + PCI_SUBSYSTEM_VENDOR_ID, d->vendor_id);
+    pci_set_word(pci_conf + PCI_DEVICE_ID, d->device_id);
+    pci_set_word(pci_conf + PCI_SUBSYSTEM_ID, d->device_id);
+    pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
+
+    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
+
+    pci_config_set_prog_interface(pci_conf, 0);
+
+    pci_conf[PCI_INTERRUPT_PIN] = 1;
+
+    memory_region_init_io(&d->mmio, NULL, &xen_pv_mmio_ops, d,
+                          "mmio", d->size);
+
+    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
+                     &d->mmio);
+}
+
+static Property xen_pv_props[] = {
+    DEFINE_PROP_UINT16("vendor-id", XenPVDevice, vendor_id, PCI_VENDOR_ID_XEN),
+    DEFINE_PROP_UINT16("device-id", XenPVDevice, device_id, 0xffff),
+    DEFINE_PROP_UINT8("revision", XenPVDevice, revision, 0x01),
+    DEFINE_PROP_UINT32("size", XenPVDevice, size, 0x400000),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void xen_pv_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->realize = xen_pv_realize;
+    k->class_id = PCI_CLASS_SYSTEM_OTHER;
+    dc->desc = "Xen PV Device";
+    device_class_set_props(dc, xen_pv_props);
+    dc->vmsd = &vmstate_xen_pvdevice;
+}
+
+static const TypeInfo xen_pv_type_info = {
+    .name          = TYPE_XEN_PV_DEVICE,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(XenPVDevice),
+    .class_init    = xen_pv_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { },
+    },
+};
+
+static void xen_pv_register_types(void)
+{
+    type_register_static(&xen_pv_type_info);
+}
+
+type_init(xen_pv_register_types)