vfio-user: find and init PCI device

Find the PCI device with specified id. Initialize the device context
with the QEMU PCI device

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 7798dbd730099b33fdd00c4c202cfe79e5c5c151.1655151679.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

hw/remote/vfio-user-obj.c

@@ -43,6 +43,8 @@
 #include "qemu/notify.h"
 #include "sysemu/sysemu.h"
 #include "libvfio-user.h"
+#include "hw/qdev-core.h"
+#include "hw/pci/pci.h"
 
 #define TYPE_VFU_OBJECT "x-vfio-user-server"
 OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
@@ -80,6 +82,10 @@ struct VfuObject {
     Notifier machine_done;
 
     vfu_ctx_t *vfu_ctx;
+
+    PCIDevice *pci_dev;
+
+    Error *unplug_blocker;
 };
 
 static void vfu_object_init_ctx(VfuObject *o, Error **errp);
@@ -181,6 +187,9 @@ static void vfu_object_machine_done(Notifier *notifier, void *data)
 static void vfu_object_init_ctx(VfuObject *o, Error **errp)
 {
     ERRP_GUARD();
+    DeviceState *dev = NULL;
+    vfu_pci_type_t pci_type = VFU_PCI_TYPE_CONVENTIONAL;
+    int ret;
 
     if (o->vfu_ctx || !o->socket || !o->device ||
             !phase_check(PHASE_MACHINE_READY)) {
@@ -199,6 +208,53 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp)
         error_setg(errp, "vfu: Failed to create context - %s", strerror(errno));
         return;
     }
+
+    dev = qdev_find_recursive(sysbus_get_default(), o->device);
+    if (dev == NULL) {
+        error_setg(errp, "vfu: Device %s not found", o->device);
+        goto fail;
+    }
+
+    if (!object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        error_setg(errp, "vfu: %s not a PCI device", o->device);
+        goto fail;
+    }
+
+    o->pci_dev = PCI_DEVICE(dev);
+
+    object_ref(OBJECT(o->pci_dev));
+
+    if (pci_is_express(o->pci_dev)) {
+        pci_type = VFU_PCI_TYPE_EXPRESS;
+    }
+
+    ret = vfu_pci_init(o->vfu_ctx, pci_type, PCI_HEADER_TYPE_NORMAL, 0);
+    if (ret < 0) {
+        error_setg(errp,
+                   "vfu: Failed to attach PCI device %s to context - %s",
+                   o->device, strerror(errno));
+        goto fail;
+    }
+
+    error_setg(&o->unplug_blocker,
+               "vfu: %s for %s must be deleted before unplugging",
+               TYPE_VFU_OBJECT, o->device);
+    qdev_add_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+
+    return;
+
+fail:
+    vfu_destroy_ctx(o->vfu_ctx);
+    if (o->unplug_blocker && o->pci_dev) {
+        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+        error_free(o->unplug_blocker);
+        o->unplug_blocker = NULL;
+    }
+    if (o->pci_dev) {
+        object_unref(OBJECT(o->pci_dev));
+        o->pci_dev = NULL;
+    }
+    o->vfu_ctx = NULL;
 }
 
 static void vfu_object_init(Object *obj)
@@ -241,6 +297,17 @@ static void vfu_object_finalize(Object *obj)
 
     o->device = NULL;
 
+    if (o->unplug_blocker && o->pci_dev) {
+        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+        error_free(o->unplug_blocker);
+        o->unplug_blocker = NULL;
+    }
+
+    if (o->pci_dev) {
+        object_unref(OBJECT(o->pci_dev));
+        o->pci_dev = NULL;
+    }
+
     if (!k->nr_devs && vfu_object_auto_shutdown()) {
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
     }