Xen PV Device

Introduces a new Xen PV PCI device which will act as a binding point for
PV drivers for Xen.
The device has parameterized vendor-id, device-id and revision to allow to
be configured as a binding point for any vendor's PV drivers.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>

4 files changed, 139 insertions, 3 deletions

diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs
index 2017560..ce640c6 100644
--- a/hw/xen/Makefile.objs
+++ b/hw/xen/Makefile.objs
@@ -1,6 +1,6 @@
 # xen backend driver support
 common-obj-$(CONFIG_XEN_BACKEND) += xen_backend.o xen_devconfig.o
 
-obj-$(CONFIG_XEN_I386) += xen_platform.o xen_apic.o
+obj-$(CONFIG_XEN_I386) += xen_platform.o xen_apic.o xen_pvdevice.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_msi.o
diff --git a/hw/xen/xen_pvdevice.c b/hw/xen/xen_pvdevice.c
new file mode 100644
index 0000000..1132c89
--- /dev/null
+++ b/hw/xen/xen_pvdevice.c
@@ -0,0 +1,131 @@
+/* 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 "hw/hw.h"
+#include "hw/pci/pci.h"
+#include "trace.h"
+
+#define TYPE_XEN_PV_DEVICE  "xen-pvdevice"
+
+#define XEN_PV_DEVICE(obj) \
+     OBJECT_CHECK(XenPVDevice, (obj), TYPE_XEN_PV_DEVICE)
+
+typedef struct XenPVDevice {
+    /*< private >*/
+    PCIDevice       parent_obj;
+    /*< public >*/
+    uint16_t        vendor_id;
+    uint16_t        device_id;
+    uint8_t         revision;
+    uint32_t        size;
+    MemoryRegion    mmio;
+} XenPVDevice;
+
+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 int xen_pv_init(PCIDevice *pci_dev)
+{
+    XenPVDevice *d = XEN_PV_DEVICE(pci_dev);
+    uint8_t *pci_conf;
+
+    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);
+
+    return 0;
+}
+
+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, PCI_DEVICE_ID_XEN_PVDEVICE),
+    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->init = xen_pv_init;
+    k->class_id = PCI_CLASS_SYSTEM_OTHER;
+    dc->desc = "Xen PV Device";
+    dc->props = xen_pv_props;
+}
+
+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,
+};
+
+static void xen_pv_register_types(void)
+{
+    type_register_static(&xen_pv_type_info);
+}
+
+type_init(xen_pv_register_types)
diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
index d7933bf..3ddaf6a 100644
--- a/include/hw/pci/pci_ids.h
+++ b/include/hw/pci/pci_ids.h
@@ -143,8 +143,9 @@
 
 #define PCI_DEVICE_ID_INTEL_Q35_MCH      0x29c0
 
-#define PCI_VENDOR_ID_XEN               0x5853
-#define PCI_DEVICE_ID_XEN_PLATFORM      0x0001
+#define PCI_VENDOR_ID_XEN                0x5853
+#define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
+#define PCI_DEVICE_ID_XEN_PVDEVICE       0x0002
 
 #define PCI_VENDOR_ID_NEC                0x1033
 #define PCI_DEVICE_ID_NEC_UPD720200      0x0194
diff --git a/trace-events b/trace-events
index 002df83..0f7c8b4 100644
--- a/trace-events
+++ b/trace-events
@@ -1168,3 +1168,7 @@ kvm_run_exit(int cpu_index, uint32_t reason) "cpu_index %d, reason %d"
 # qom/object.c
 object_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
 object_class_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
+
+# hw/xen/xen_pvdevice.c
+xen_pv_mmio_read(uint64_t addr) "WARNING: read from Xen PV Device MMIO space (address %"PRIx64")"
+xen_pv_mmio_write(uint64_t addr) "WARNING: write to Xen PV Device MMIO space (address %"PRIx64")"