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, 186 insertions, 0 deletions

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
new file mode 100644
index 000000000..e0dd561e8
--- /dev/null
+++ b/hw/vfio/ap.c
@@ -0,0 +1,186 @@
+/*
+ * VFIO based AP matrix device assignment
+ *
+ * Copyright 2018 IBM Corp.
+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
+ *            Halil Pasic <pasic@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+#include <linux/vfio.h>
+#include <sys/ioctl.h>
+#include "qapi/error.h"
+#include "hw/vfio/vfio.h"
+#include "hw/vfio/vfio-common.h"
+#include "hw/s390x/ap-device.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "qemu/option.h"
+#include "qemu/config-file.h"
+#include "kvm/kvm_s390x.h"
+#include "migration/vmstate.h"
+#include "hw/qdev-properties.h"
+#include "hw/s390x/ap-bridge.h"
+#include "exec/address-spaces.h"
+#include "qom/object.h"
+
+#define TYPE_VFIO_AP_DEVICE      "vfio-ap"
+
+struct VFIOAPDevice {
+    APDevice apdev;
+    VFIODevice vdev;
+};
+
+OBJECT_DECLARE_SIMPLE_TYPE(VFIOAPDevice, VFIO_AP_DEVICE)
+
+static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
+{
+    vdev->needs_reset = false;
+}
+
+/*
+ * We don't need vfio_hot_reset_multi and vfio_eoi operations for
+ * vfio-ap device now.
+ */
+struct VFIODeviceOps vfio_ap_ops = {
+    .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
+};
+
+static void vfio_ap_put_device(VFIOAPDevice *vapdev)
+{
+    g_free(vapdev->vdev.name);
+    vfio_put_base_device(&vapdev->vdev);
+}
+
+static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
+{
+    GError *gerror = NULL;
+    char *symlink, *group_path;
+    int groupid;
+
+    symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
+    group_path = g_file_read_link(symlink, &gerror);
+    g_free(symlink);
+
+    if (!group_path) {
+        error_setg(errp, "%s: no iommu_group found for %s: %s",
+                   TYPE_VFIO_AP_DEVICE, vapdev->vdev.sysfsdev, gerror->message);
+        g_error_free(gerror);
+        return NULL;
+    }
+
+    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
+        error_setg(errp, "vfio: failed to read %s", group_path);
+        g_free(group_path);
+        return NULL;
+    }
+
+    g_free(group_path);
+
+    return vfio_get_group(groupid, &address_space_memory, errp);
+}
+
+static void vfio_ap_realize(DeviceState *dev, Error **errp)
+{
+    int ret;
+    char *mdevid;
+    VFIOGroup *vfio_group;
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+
+    vfio_group = vfio_ap_get_group(vapdev, errp);
+    if (!vfio_group) {
+        return;
+    }
+
+    vapdev->vdev.ops = &vfio_ap_ops;
+    vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
+    mdevid = basename(vapdev->vdev.sysfsdev);
+    vapdev->vdev.name = g_strdup_printf("%s", mdevid);
+    vapdev->vdev.dev = dev;
+
+    /*
+     * vfio-ap devices operate in a way compatible with discarding of
+     * memory in RAM blocks, as no pages are pinned in the host.
+     * This needs to be set before vfio_get_device() for vfio common to
+     * handle ram_block_discard_disable().
+     */
+    vapdev->vdev.ram_block_discard_allowed = true;
+
+    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
+    if (ret) {
+        goto out_get_dev_err;
+    }
+
+    return;
+
+out_get_dev_err:
+    vfio_ap_put_device(vapdev);
+    vfio_put_group(vfio_group);
+}
+
+static void vfio_ap_unrealize(DeviceState *dev)
+{
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+    VFIOGroup *group = vapdev->vdev.group;
+
+    vfio_ap_put_device(vapdev);
+    vfio_put_group(group);
+}
+
+static Property vfio_ap_properties[] = {
+    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vfio_ap_reset(DeviceState *dev)
+{
+    int ret;
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+
+    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
+    if (ret) {
+        error_report("%s: failed to reset %s device: %s", __func__,
+                     vapdev->vdev.name, strerror(errno));
+    }
+}
+
+static const VMStateDescription vfio_ap_vmstate = {
+    .name = "vfio-ap",
+    .unmigratable = 1,
+};
+
+static void vfio_ap_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    device_class_set_props(dc, vfio_ap_properties);
+    dc->vmsd = &vfio_ap_vmstate;
+    dc->desc = "VFIO-based AP device assignment";
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    dc->realize = vfio_ap_realize;
+    dc->unrealize = vfio_ap_unrealize;
+    dc->hotpluggable = true;
+    dc->reset = vfio_ap_reset;
+    dc->bus_type = TYPE_AP_BUS;
+}
+
+static const TypeInfo vfio_ap_info = {
+    .name = TYPE_VFIO_AP_DEVICE,
+    .parent = TYPE_AP_DEVICE,
+    .instance_size = sizeof(VFIOAPDevice),
+    .class_init = vfio_ap_class_init,
+};
+
+static void vfio_ap_type_init(void)
+{
+    type_register_static(&vfio_ap_info);
+}
+
+type_init(vfio_ap_type_init)