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, 519 insertions, 0 deletions

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
new file mode 100644
index 000000000..72028449b
--- /dev/null
+++ b/hw/i386/xen/xen_platform.c
@@ -0,0 +1,519 @@
+/*
+ * XEN platform pci device, formerly known as the event channel device
+ *
+ * Copyright (c) 2003-2004 Intel Corp.
+ * Copyright (c) 2006 XenSource
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/ide.h"
+#include "hw/pci/pci.h"
+#include "hw/xen/xen_common.h"
+#include "migration/vmstate.h"
+#include "hw/xen/xen-legacy-backend.h"
+#include "trace.h"
+#include "sysemu/xen.h"
+#include "sysemu/block-backend.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "qom/object.h"
+
+//#define DEBUG_PLATFORM
+
+#ifdef DEBUG_PLATFORM
+#define DPRINTF(fmt, ...) do { \
+    fprintf(stderr, "xen_platform: " fmt, ## __VA_ARGS__); \
+} while (0)
+#else
+#define DPRINTF(fmt, ...) do { } while (0)
+#endif
+
+#define PFFLAG_ROM_LOCK 1 /* Sets whether ROM memory area is RW or RO */
+
+struct PCIXenPlatformState {
+    /*< private >*/
+    PCIDevice parent_obj;
+    /*< public >*/
+
+    MemoryRegion fixed_io;
+    MemoryRegion bar;
+    MemoryRegion mmio_bar;
+    uint8_t flags; /* used only for version_id == 2 */
+    uint16_t driver_product_version;
+
+    /* Log from guest drivers */
+    char log_buffer[4096];
+    int log_buffer_off;
+};
+
+#define TYPE_XEN_PLATFORM "xen-platform"
+OBJECT_DECLARE_SIMPLE_TYPE(PCIXenPlatformState, XEN_PLATFORM)
+
+#define XEN_PLATFORM_IOPORT 0x10
+
+/* Send bytes to syslog */
+static void log_writeb(PCIXenPlatformState *s, char val)
+{
+    if (val == '\n' || s->log_buffer_off == sizeof(s->log_buffer) - 1) {
+        /* Flush buffer */
+        s->log_buffer[s->log_buffer_off] = 0;
+        trace_xen_platform_log(s->log_buffer);
+        s->log_buffer_off = 0;
+    } else {
+        s->log_buffer[s->log_buffer_off++] = val;
+    }
+}
+
+/*
+ * Unplug device flags.
+ *
+ * The logic got a little confused at some point in the past but this is
+ * what they do now.
+ *
+ * bit 0: Unplug all IDE and SCSI disks.
+ * bit 1: Unplug all NICs.
+ * bit 2: Unplug IDE disks except primary master. This is overridden if
+ *        bit 0 is also present in the mask.
+ * bit 3: Unplug all NVMe disks.
+ *
+ */
+#define _UNPLUG_IDE_SCSI_DISKS 0
+#define UNPLUG_IDE_SCSI_DISKS (1u << _UNPLUG_IDE_SCSI_DISKS)
+
+#define _UNPLUG_ALL_NICS 1
+#define UNPLUG_ALL_NICS (1u << _UNPLUG_ALL_NICS)
+
+#define _UNPLUG_AUX_IDE_DISKS 2
+#define UNPLUG_AUX_IDE_DISKS (1u << _UNPLUG_AUX_IDE_DISKS)
+
+#define _UNPLUG_NVME_DISKS 3
+#define UNPLUG_NVME_DISKS (1u << _UNPLUG_NVME_DISKS)
+
+static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
+{
+    /* We have to ignore passthrough devices */
+    if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
+            PCI_CLASS_NETWORK_ETHERNET
+            && strcmp(d->name, "xen-pci-passthrough") != 0) {
+        object_unparent(OBJECT(d));
+    }
+}
+
+/* Remove the peer of the NIC device. Normally, this would be a tap device. */
+static void del_nic_peer(NICState *nic, void *opaque)
+{
+    NetClientState *nc;
+
+    nc = qemu_get_queue(nic);
+    if (nc->peer)
+        qemu_del_net_client(nc->peer);
+}
+
+static void pci_unplug_nics(PCIBus *bus)
+{
+    qemu_foreach_nic(del_nic_peer, NULL);
+    pci_for_each_device(bus, 0, unplug_nic, NULL);
+}
+
+static void unplug_disks(PCIBus *b, PCIDevice *d, void *opaque)
+{
+    uint32_t flags = *(uint32_t *)opaque;
+    bool aux = (flags & UNPLUG_AUX_IDE_DISKS) &&
+        !(flags & UNPLUG_IDE_SCSI_DISKS);
+
+    /* We have to ignore passthrough devices */
+    if (!strcmp(d->name, "xen-pci-passthrough")) {
+        return;
+    }
+
+    switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
+    case PCI_CLASS_STORAGE_IDE:
+        pci_piix3_xen_ide_unplug(DEVICE(d), aux);
+        break;
+
+    case PCI_CLASS_STORAGE_SCSI:
+        if (!aux) {
+            object_unparent(OBJECT(d));
+        }
+        break;
+
+    case PCI_CLASS_STORAGE_EXPRESS:
+        if (flags & UNPLUG_NVME_DISKS) {
+            object_unparent(OBJECT(d));
+        }
+
+    default:
+        break;
+    }
+}
+
+static void pci_unplug_disks(PCIBus *bus, uint32_t flags)
+{
+    pci_for_each_device(bus, 0, unplug_disks, &flags);
+}
+
+static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIXenPlatformState *s = opaque;
+
+    switch (addr) {
+    case 0: {
+        PCIDevice *pci_dev = PCI_DEVICE(s);
+        /* Unplug devices. See comment above flag definitions */
+        if (val & (UNPLUG_IDE_SCSI_DISKS | UNPLUG_AUX_IDE_DISKS |
+                   UNPLUG_NVME_DISKS)) {
+            DPRINTF("unplug disks\n");
+            pci_unplug_disks(pci_get_bus(pci_dev), val);
+        }
+        if (val & UNPLUG_ALL_NICS) {
+            DPRINTF("unplug nics\n");
+            pci_unplug_nics(pci_get_bus(pci_dev));
+        }
+        break;
+    }
+    case 2:
+        switch (val) {
+        case 1:
+            DPRINTF("Citrix Windows PV drivers loaded in guest\n");
+            break;
+        case 0:
+            DPRINTF("Guest claimed to be running PV product 0?\n");
+            break;
+        default:
+            DPRINTF("Unknown PV product %d loaded in guest\n", val);
+            break;
+        }
+        s->driver_product_version = val;
+        break;
+    }
+}
+
+static void platform_fixed_ioport_writel(void *opaque, uint32_t addr,
+                                         uint32_t val)
+{
+    switch (addr) {
+    case 0:
+        /* PV driver version */
+        break;
+    }
+}
+
+static void platform_fixed_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIXenPlatformState *s = opaque;
+
+    switch (addr) {
+    case 0: /* Platform flags */ {
+        hvmmem_type_t mem_type = (val & PFFLAG_ROM_LOCK) ?
+            HVMMEM_ram_ro : HVMMEM_ram_rw;
+        if (xen_set_mem_type(xen_domid, mem_type, 0xc0, 0x40)) {
+            DPRINTF("unable to change ro/rw state of ROM memory area!\n");
+        } else {
+            s->flags = val & PFFLAG_ROM_LOCK;
+            DPRINTF("changed ro/rw state of ROM memory area. now is %s state.\n",
+                    (mem_type == HVMMEM_ram_ro ? "ro":"rw"));
+        }
+        break;
+    }
+    case 2:
+        log_writeb(s, val);
+        break;
+    }
+}
+
+static uint32_t platform_fixed_ioport_readw(void *opaque, uint32_t addr)
+{
+    switch (addr) {
+    case 0:
+        /* Magic value so that you can identify the interface. */
+        return 0x49d2;
+    default:
+        return 0xffff;
+    }
+}
+
+static uint32_t platform_fixed_ioport_readb(void *opaque, uint32_t addr)
+{
+    PCIXenPlatformState *s = opaque;
+
+    switch (addr) {
+    case 0:
+        /* Platform flags */
+        return s->flags;
+    case 2:
+        /* Version number */
+        return 1;
+    default:
+        return 0xff;
+    }
+}
+
+static void platform_fixed_ioport_reset(void *opaque)
+{
+    PCIXenPlatformState *s = opaque;
+
+    platform_fixed_ioport_writeb(s, 0, 0);
+}
+
+static uint64_t platform_fixed_ioport_read(void *opaque,
+                                           hwaddr addr,
+                                           unsigned size)
+{
+    switch (size) {
+    case 1:
+        return platform_fixed_ioport_readb(opaque, addr);
+    case 2:
+        return platform_fixed_ioport_readw(opaque, addr);
+    default:
+        return -1;
+    }
+}
+
+static void platform_fixed_ioport_write(void *opaque, hwaddr addr,
+
+                                        uint64_t val, unsigned size)
+{
+    switch (size) {
+    case 1:
+        platform_fixed_ioport_writeb(opaque, addr, val);
+        break;
+    case 2:
+        platform_fixed_ioport_writew(opaque, addr, val);
+        break;
+    case 4:
+        platform_fixed_ioport_writel(opaque, addr, val);
+        break;
+    }
+}
+
+
+static const MemoryRegionOps platform_fixed_io_ops = {
+    .read = platform_fixed_ioport_read,
+    .write = platform_fixed_ioport_write,
+    .valid = {
+        .unaligned = true,
+    },
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+        .unaligned = true,
+    },
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void platform_fixed_ioport_init(PCIXenPlatformState* s)
+{
+    memory_region_init_io(&s->fixed_io, OBJECT(s), &platform_fixed_io_ops, s,
+                          "xen-fixed", 16);
+    memory_region_add_subregion(get_system_io(), XEN_PLATFORM_IOPORT,
+                                &s->fixed_io);
+}
+
+/* Xen Platform PCI Device */
+
+static uint64_t xen_platform_ioport_readb(void *opaque, hwaddr addr,
+                                          unsigned int size)
+{
+    if (addr == 0) {
+        return platform_fixed_ioport_readb(opaque, 0);
+    } else {
+        return ~0u;
+    }
+}
+
+static void xen_platform_ioport_writeb(void *opaque, hwaddr addr,
+                                       uint64_t val, unsigned int size)
+{
+    PCIXenPlatformState *s = opaque;
+    PCIDevice *pci_dev = PCI_DEVICE(s);
+
+    switch (addr) {
+    case 0: /* Platform flags */
+        platform_fixed_ioport_writeb(opaque, 0, (uint32_t)val);
+        break;
+    case 4:
+        if (val == 1) {
+            /*
+             * SUSE unplug for Xenlinux
+             * xen-kmp used this since xen-3.0.4, instead the official protocol
+             * from xen-3.3+ It did an unconditional "outl(1, (ioaddr + 4));"
+             * Pre VMDP 1.7 used 4 and 8 depending on how VMDP was configured.
+             * If VMDP was to control both disk and LAN it would use 4.
+             * If it controlled just disk or just LAN, it would use 8 below.
+             */
+            pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
+            pci_unplug_nics(pci_get_bus(pci_dev));
+        }
+        break;
+    case 8:
+        switch (val) {
+        case 1:
+            pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
+            break;
+        case 2:
+            pci_unplug_nics(pci_get_bus(pci_dev));
+            break;
+        default:
+            log_writeb(s, (uint32_t)val);
+            break;
+        }
+        break;
+    default:
+        break;
+    }
+}
+
+static const MemoryRegionOps xen_pci_io_ops = {
+    .read  = xen_platform_ioport_readb,
+    .write = xen_platform_ioport_writeb,
+    .impl.min_access_size = 1,
+    .impl.max_access_size = 1,
+};
+
+static void platform_ioport_bar_setup(PCIXenPlatformState *d)
+{
+    memory_region_init_io(&d->bar, OBJECT(d), &xen_pci_io_ops, d,
+                          "xen-pci", 0x100);
+}
+
+static uint64_t platform_mmio_read(void *opaque, hwaddr addr,
+                                   unsigned size)
+{
+    DPRINTF("Warning: attempted read from physical address "
+            "0x" TARGET_FMT_plx " in xen platform mmio space\n", addr);
+
+    return 0;
+}
+
+static void platform_mmio_write(void *opaque, hwaddr addr,
+                                uint64_t val, unsigned size)
+{
+    DPRINTF("Warning: attempted write of 0x%"PRIx64" to physical "
+            "address 0x" TARGET_FMT_plx " in xen platform mmio space\n",
+            val, addr);
+}
+
+static const MemoryRegionOps platform_mmio_handler = {
+    .read = &platform_mmio_read,
+    .write = &platform_mmio_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void platform_mmio_setup(PCIXenPlatformState *d)
+{
+    memory_region_init_io(&d->mmio_bar, OBJECT(d), &platform_mmio_handler, d,
+                          "xen-mmio", 0x1000000);
+}
+
+static int xen_platform_post_load(void *opaque, int version_id)
+{
+    PCIXenPlatformState *s = opaque;
+
+    platform_fixed_ioport_writeb(s, 0, s->flags);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_xen_platform = {
+    .name = "platform",
+    .version_id = 4,
+    .minimum_version_id = 4,
+    .post_load = xen_platform_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_PCI_DEVICE(parent_obj, PCIXenPlatformState),
+        VMSTATE_UINT8(flags, PCIXenPlatformState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void xen_platform_realize(PCIDevice *dev, Error **errp)
+{
+    PCIXenPlatformState *d = XEN_PLATFORM(dev);
+    uint8_t *pci_conf;
+
+    /* Device will crash on reset if xen is not initialized */
+    if (!xen_enabled()) {
+        error_setg(errp, "xen-platform device requires the Xen accelerator");
+        return;
+    }
+
+    pci_conf = dev->config;
+
+    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+
+    pci_config_set_prog_interface(pci_conf, 0);
+
+    pci_conf[PCI_INTERRUPT_PIN] = 1;
+
+    platform_ioport_bar_setup(d);
+    pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_IO, &d->bar);
+
+    /* reserve 16MB mmio address for share memory*/
+    platform_mmio_setup(d);
+    pci_register_bar(dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
+                     &d->mmio_bar);
+
+    platform_fixed_ioport_init(d);
+}
+
+static void platform_reset(DeviceState *dev)
+{
+    PCIXenPlatformState *s = XEN_PLATFORM(dev);
+
+    platform_fixed_ioport_reset(s);
+}
+
+static void xen_platform_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->realize = xen_platform_realize;
+    k->vendor_id = PCI_VENDOR_ID_XEN;
+    k->device_id = PCI_DEVICE_ID_XEN_PLATFORM;
+    k->class_id = PCI_CLASS_OTHERS << 8 | 0x80;
+    k->subsystem_vendor_id = PCI_VENDOR_ID_XEN;
+    k->subsystem_id = PCI_DEVICE_ID_XEN_PLATFORM;
+    k->revision = 1;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    dc->desc = "XEN platform pci device";
+    dc->reset = platform_reset;
+    dc->vmsd = &vmstate_xen_platform;
+}
+
+static const TypeInfo xen_platform_info = {
+    .name          = TYPE_XEN_PLATFORM,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIXenPlatformState),
+    .class_init    = xen_platform_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { },
+    },
+};
+
+static void xen_platform_register_types(void)
+{
+    type_register_static(&xen_platform_info);
+}
+
+type_init(xen_platform_register_types)