Merge remote-tracking branch 'remotes/aperard/tags/pull-xen-20190114' into staging

Xen queue

* Xen PV backend 'qdevification'.
  Starting with xen_disk.
* Performance improvements for xen-block.
* Remove of the Xen PV domain builder.
* bug fixes.

# gpg: Signature made Mon 14 Jan 2019 13:46:33 GMT
# gpg:                using RSA key 0CF5572FD7FB55AF
# gpg: Good signature from "Anthony PERARD <anthony.perard@gmail.com>"
# gpg:                 aka "Anthony PERARD <anthony.perard@citrix.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5379 2F71 024C 600F 778A  7161 D8D5 7199 DF83 42C8
#      Subkey fingerprint: F80C 0063 08E2 2CFD 8A92  E798 0CF5 572F D7FB 55AF

* remotes/aperard/tags/pull-xen-20190114: (25 commits)
  xen-block: avoid repeated memory allocation
  xen-block: improve response latency
  xen-block: improve batching behaviour
  xen: Replace few mentions of xend by libxl
  Remove broken Xen PV domain builder
  xen: remove the legacy 'xen_disk' backend
  MAINTAINERS: add myself as a Xen maintainer
  xen: automatically create XenBlockDevice-s
  xen: add a mechanism to automatically create XenDevice-s...
  xen: add implementations of xen-block connect and disconnect functions...
  xen: purge 'blk' and 'ioreq' from function names in dataplane/xen-block.c
  xen: remove 'ioreq' struct/varable/field names from dataplane/xen-block.c
  xen: remove 'XenBlkDev' and 'blkdev' names from dataplane/xen-block
  xen: add header and build dataplane/xen-block.c
  xen: remove unnecessary code from dataplane/xen-block.c
  xen: duplicate xen_disk.c as basis of dataplane/xen-block.c
  xen: add event channel interface for XenDevice-s
  xen: add grant table interface for XenDevice-s
  xen: add xenstore watcher infrastructure
  xen: create xenstore areas for XenDevice-s
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

MAINTAINERS

@@ -407,6 +407,7 @@ Guest CPU Cores (Xen):
 X86
 M: Stefano Stabellini <sstabellini@kernel.org>
 M: Anthony Perard <anthony.perard@citrix.com>
+M: Paul Durrant <paul.durrant@citrix.com>
 L: xen-devel@lists.xenproject.org
 S: Supported
 F: */xen*
@@ -414,10 +415,12 @@ F: hw/9pfs/xen-9p-backend.c
 F: hw/char/xen_console.c
 F: hw/display/xenfb.c
 F: hw/net/xen_nic.c
-F: hw/block/xen_*
+F: hw/block/xen*
+F: hw/block/dataplane/xen*
 F: hw/xen/
 F: hw/xenpv/
 F: hw/i386/xen/
+F: include/hw/block/dataplane/xen*
 F: include/hw/xen/
 F: include/sysemu/xen-mapcache.h
 

configure

@@ -357,7 +357,6 @@ vnc_png=""
 xkbcommon=""
 xen=""
 xen_ctrl_version=""
-xen_pv_domain_build="no"
 xen_pci_passthrough=""
 linux_aio=""
 cap_ng=""
@@ -1119,10 +1118,6 @@ for opt do
   ;;
   --enable-xen-pci-passthrough) xen_pci_passthrough="yes"
   ;;
-  --disable-xen-pv-domain-build) xen_pv_domain_build="no"
-  ;;
-  --enable-xen-pv-domain-build) xen_pv_domain_build="yes"
-  ;;
   --disable-brlapi) brlapi="no"
   ;;
   --enable-brlapi) brlapi="yes"
@@ -1685,8 +1680,6 @@ Advanced options (experts only):
   --tls-priority           default TLS protocol/cipher priority string
   --enable-gprof           QEMU profiling with gprof
   --enable-profiler        profiler support
-  --enable-xen-pv-domain-build
-                           xen pv domain builder
   --enable-debug-stack-usage
                            track the maximum stack usage of stacks created by qemu_alloc_stack
 
@@ -2678,12 +2671,6 @@ if test "$xen_pci_passthrough" != "no"; then
   fi
 fi
 
-if test "$xen_pv_domain_build" = "yes" &&
-   test "$xen" != "yes"; then
-    error_exit "User requested Xen PV domain builder support" \
-	       "which requires Xen support."
-fi
-
 ##########################################
 # Windows Hypervisor Platform accelerator (WHPX) check
 if test "$whpx" != "no" ; then
@@ -6069,7 +6056,6 @@ fi
 echo "xen support       $xen"
 if test "$xen" = "yes" ; then
   echo "xen ctrl version  $xen_ctrl_version"
-  echo "pv dom build      $xen_pv_domain_build"
 fi
 echo "brlapi support    $brlapi"
 echo "bluez  support    $bluez"
@@ -6539,9 +6525,6 @@ fi
 if test "$xen" = "yes" ; then
   echo "CONFIG_XEN_BACKEND=y" >> $config_host_mak
   echo "CONFIG_XEN_CTRL_INTERFACE_VERSION=$xen_ctrl_version" >> $config_host_mak
-  if test "$xen_pv_domain_build" = "yes" ; then
-    echo "CONFIG_XEN_PV_DOMAIN_BUILD=y" >> $config_host_mak
-  fi
 fi
 if test "$linux_aio" = "yes" ; then
   echo "CONFIG_LINUX_AIO=y" >> $config_host_mak

hw/9pfs/xen-9p-backend.c

@@ -12,7 +12,7 @@
 
 #include "hw/hw.h"
 #include "hw/9pfs/9p.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 #include "hw/9pfs/xen-9pfs.h"
 #include "qapi/error.h"
 #include "qemu/config-file.h"
@@ -45,7 +45,7 @@ typedef struct Xen9pfsRing {
 } Xen9pfsRing;
 
 typedef struct Xen9pfsDev {
-    struct XenDevice xendev;  /* must be first */
+    struct XenLegacyDevice xendev;  /* must be first */
     V9fsState state;
     char *path;
     char *security_model;
@@ -56,7 +56,7 @@ typedef struct Xen9pfsDev {
     Xen9pfsRing *rings;
 } Xen9pfsDev;
 
-static void xen_9pfs_disconnect(struct XenDevice *xendev);
+static void xen_9pfs_disconnect(struct XenLegacyDevice *xendev);
 
 static void xen_9pfs_in_sg(Xen9pfsRing *ring,
                            struct iovec *in_sg,
@@ -243,7 +243,7 @@ static const V9fsTransport xen_9p_transport = {
     .push_and_notify = xen_9pfs_push_and_notify,
 };
 
-static int xen_9pfs_init(struct XenDevice *xendev)
+static int xen_9pfs_init(struct XenLegacyDevice *xendev)
 {
     return 0;
 }
@@ -305,7 +305,7 @@ static void xen_9pfs_evtchn_event(void *opaque)
     qemu_bh_schedule(ring->bh);
 }
 
-static void xen_9pfs_disconnect(struct XenDevice *xendev)
+static void xen_9pfs_disconnect(struct XenLegacyDevice *xendev)
 {
     Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
     int i;
@@ -321,7 +321,7 @@ static void xen_9pfs_disconnect(struct XenDevice *xendev)
     }
 }
 
-static int xen_9pfs_free(struct XenDevice *xendev)
+static int xen_9pfs_free(struct XenLegacyDevice *xendev)
 {
     Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
     int i;
@@ -354,7 +354,7 @@ static int xen_9pfs_free(struct XenDevice *xendev)
     return 0;
 }
 
-static int xen_9pfs_connect(struct XenDevice *xendev)
+static int xen_9pfs_connect(struct XenLegacyDevice *xendev)
 {
     Error *err = NULL;
     int i;
@@ -467,7 +467,7 @@ out:
     return -1;
 }
 
-static void xen_9pfs_alloc(struct XenDevice *xendev)
+static void xen_9pfs_alloc(struct XenLegacyDevice *xendev)
 {
     xenstore_write_be_str(xendev, "versions", VERSIONS);
     xenstore_write_be_int(xendev, "max-rings", MAX_RINGS);

hw/block/Makefile.objs

@@ -4,7 +4,7 @@ common-obj-$(CONFIG_SSI_M25P80) += m25p80.o
 common-obj-$(CONFIG_NAND) += nand.o
 common-obj-$(CONFIG_PFLASH_CFI01) += pflash_cfi01.o
 common-obj-$(CONFIG_PFLASH_CFI02) += pflash_cfi02.o
-common-obj-$(CONFIG_XEN) += xen_disk.o
+common-obj-$(CONFIG_XEN) += xen-block.o
 common-obj-$(CONFIG_ECC) += ecc.o
 common-obj-$(CONFIG_ONENAND) += onenand.o
 common-obj-$(CONFIG_NVME_PCI) += nvme.o

hw/block/dataplane/Makefile.objs

@@ -1 +1,2 @@
 obj-y += virtio-blk.o
+obj-$(CONFIG_XEN) += xen-block.o

hw/block/dataplane/xen-block.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018  Citrix Systems Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_BLOCK_DATAPLANE_XEN_BLOCK_H
+#define HW_BLOCK_DATAPLANE_XEN_BLOCK_H
+
+#include "hw/block/block.h"
+#include "hw/xen/xen-bus.h"
+#include "sysemu/iothread.h"
+
+typedef struct XenBlockDataPlane XenBlockDataPlane;
+
+XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev,
+                                              BlockConf *conf,
+                                              IOThread *iothread);
+void xen_block_dataplane_destroy(XenBlockDataPlane *dataplane);
+void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
+                               const unsigned int ring_ref[],
+                               unsigned int nr_ring_ref,
+                               unsigned int event_channel,
+                               unsigned int protocol,
+                               Error **errp);
+void xen_block_dataplane_stop(XenBlockDataPlane *dataplane);
+
+#endif /* HW_BLOCK_DATAPLANE_XEN_BLOCK_H */

hw/block/trace-events

@@ -127,3 +127,17 @@ xen_disk_init(char *name) "%s"
 xen_disk_connect(char *name) "%s"
 xen_disk_disconnect(char *name) "%s"
 xen_disk_free(char *name) "%s"
+
+# hw/block/xen-block.c
+xen_block_realize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_block_connect(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_block_disconnect(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_block_unrealize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_disk_realize(void) ""
+xen_disk_unrealize(void) ""
+xen_cdrom_realize(void) ""
+xen_cdrom_unrealize(void) ""
+xen_block_blockdev_add(char *str) "%s"
+xen_block_blockdev_del(const char *node_name) "%s"
+xen_block_device_create(unsigned int number) "%u"
+xen_block_device_destroy(unsigned int number) "%u"

hw/char/xen_console.c

@@ -26,7 +26,7 @@
 #include "qapi/error.h"
 #include "hw/hw.h"
 #include "chardev/char-fe.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 
 #include <xen/io/console.h>
 
@@ -39,7 +39,7 @@ struct buffer {
 };
 
 struct XenConsole {
-    struct XenDevice  xendev;  /* must be first */
+    struct XenLegacyDevice  xendev;  /* must be first */
     struct buffer     buffer;
     char              console[XEN_BUFSIZE];
     int               ring_ref;
@@ -173,7 +173,7 @@ static void xencons_send(struct XenConsole *con)
 
 /* -------------------------------------------------------------------- */
 
-static int con_init(struct XenDevice *xendev)
+static int con_init(struct XenLegacyDevice *xendev)
 {
     struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
     char *type, *dom, label[32];
@@ -222,7 +222,7 @@ out:
     return ret;
 }
 
-static int con_initialise(struct XenDevice *xendev)
+static int con_initialise(struct XenLegacyDevice *xendev)
 {
     struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
     int limit;
@@ -259,7 +259,7 @@ static int con_initialise(struct XenDevice *xendev)
     return 0;
 }
 
-static void con_disconnect(struct XenDevice *xendev)
+static void con_disconnect(struct XenLegacyDevice *xendev)
 {
     struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
 
@@ -276,7 +276,7 @@ static void con_disconnect(struct XenDevice *xendev)
     }
 }
 
-static void con_event(struct XenDevice *xendev)
+static void con_event(struct XenLegacyDevice *xendev)
 {
     struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
 

hw/display/xenfb.c

@@ -30,7 +30,7 @@
 #include "hw/hw.h"
 #include "ui/input.h"
 #include "ui/console.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 
 #include <xen/event_channel.h>
 #include <xen/io/fbif.h>
@@ -46,7 +46,7 @@
 /* -------------------------------------------------------------------- */
 
 struct common {
-    struct XenDevice  xendev;  /* must be first */
+    struct XenLegacyDevice  xendev;  /* must be first */
     void              *page;
 };
 
@@ -342,14 +342,14 @@ static QemuInputHandler xenfb_rel_mouse = {
     .sync  = xenfb_mouse_sync,
 };
 
-static int input_init(struct XenDevice *xendev)
+static int input_init(struct XenLegacyDevice *xendev)
 {
     xenstore_write_be_int(xendev, "feature-abs-pointer", 1);
     xenstore_write_be_int(xendev, "feature-raw-pointer", 1);
     return 0;
 }
 
-static int input_initialise(struct XenDevice *xendev)
+static int input_initialise(struct XenLegacyDevice *xendev)
 {
     struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
     int rc;
@@ -361,7 +361,7 @@ static int input_initialise(struct XenDevice *xendev)
     return 0;
 }
 
-static void input_connected(struct XenDevice *xendev)
+static void input_connected(struct XenLegacyDevice *xendev)
 {
     struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
 
@@ -395,7 +395,7 @@ static void input_connected(struct XenDevice *xendev)
     }
 }
 
-static void input_disconnect(struct XenDevice *xendev)
+static void input_disconnect(struct XenLegacyDevice *xendev)
 {
     struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
 
@@ -410,7 +410,7 @@ static void input_disconnect(struct XenDevice *xendev)
     common_unbind(&in->c);
 }
 
-static void input_event(struct XenDevice *xendev)
+static void input_event(struct XenLegacyDevice *xendev)
 {
     struct XenInput *xenfb = container_of(xendev, struct XenInput, c.xendev);
     struct xenkbd_page *page = xenfb->c.page;
@@ -867,7 +867,7 @@ static void xenfb_handle_events(struct XenFB *xenfb)
     page->out_cons = cons;
 }
 
-static int fb_init(struct XenDevice *xendev)
+static int fb_init(struct XenLegacyDevice *xendev)
 {
 #ifdef XENFB_TYPE_RESIZE
     xenstore_write_be_int(xendev, "feature-resize", 1);
@@ -875,7 +875,7 @@ static int fb_init(struct XenDevice *xendev)
     return 0;
 }
 
-static int fb_initialise(struct XenDevice *xendev)
+static int fb_initialise(struct XenLegacyDevice *xendev)
 {
     struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
     struct xenfb_page *fb_page;
@@ -912,7 +912,7 @@ static int fb_initialise(struct XenDevice *xendev)
     return 0;
 }
 
-static void fb_disconnect(struct XenDevice *xendev)
+static void fb_disconnect(struct XenLegacyDevice *xendev)
 {
     struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
 
@@ -935,7 +935,8 @@ static void fb_disconnect(struct XenDevice *xendev)
     fb->bug_trigger    = 0;
 }
 
-static void fb_frontend_changed(struct XenDevice *xendev, const char *node)
+static void fb_frontend_changed(struct XenLegacyDevice *xendev,
+                                const char *node)
 {
     struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
 
@@ -953,7 +954,7 @@ static void fb_frontend_changed(struct XenDevice *xendev, const char *node)
     }
 }
 
-static void fb_event(struct XenDevice *xendev)
+static void fb_event(struct XenLegacyDevice *xendev)
 {
     struct XenFB *xenfb = container_of(xendev, struct XenFB, c.xendev);
 

hw/i386/xen/xen-hvm.c

@@ -16,7 +16,8 @@
 #include "hw/i386/pc.h"
 #include "hw/i386/apic-msidef.h"
 #include "hw/xen/xen_common.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
+#include "hw/xen/xen-bus.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-misc.h"
 #include "qemu/error-report.h"
@@ -1484,6 +1485,8 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
     QLIST_INIT(&state->dev_list);
     device_listener_register(&state->device_listener);
 
+    xen_bus_init();
+
     /* Initialize backend core & drivers */
     if (xen_be_init() != 0) {
         error_report("xen backend core setup failed");

hw/i386/xen/xen-mapcache.c

@@ -14,7 +14,7 @@
 
 #include <sys/resource.h>
 
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 #include "qemu/bitmap.h"
 
 #include <xen/hvm/params.h>

hw/i386/xen/xen_platform.c

@@ -30,7 +30,7 @@
 #include "hw/pci/pci.h"
 #include "hw/irq.h"
 #include "hw/xen/xen_common.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 #include "trace.h"
 #include "exec/address-spaces.h"
 #include "sysemu/block-backend.h"

hw/net/xen_nic.c

@@ -28,14 +28,14 @@
 #include "net/net.h"
 #include "net/checksum.h"
 #include "net/util.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 
 #include <xen/io/netif.h>
 
 /* ------------------------------------------------------------- */
 
 struct XenNetDev {
-    struct XenDevice      xendev;  /* must be first */
+    struct XenLegacyDevice      xendev;  /* must be first */
     char                  *mac;
     int                   tx_work;
     int                   tx_ring_ref;
@@ -276,7 +276,7 @@ static NetClientInfo net_xen_info = {
     .receive = net_rx_packet,
 };
 
-static int net_init(struct XenDevice *xendev)
+static int net_init(struct XenLegacyDevice *xendev)
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
 
@@ -308,7 +308,7 @@ static int net_init(struct XenDevice *xendev)
     return 0;
 }
 
-static int net_connect(struct XenDevice *xendev)
+static int net_connect(struct XenLegacyDevice *xendev)
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
     int rx_copy;
@@ -363,7 +363,7 @@ static int net_connect(struct XenDevice *xendev)
     return 0;
 }
 
-static void net_disconnect(struct XenDevice *xendev)
+static void net_disconnect(struct XenLegacyDevice *xendev)
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
 
@@ -379,14 +379,14 @@ static void net_disconnect(struct XenDevice *xendev)
     }
 }
 
-static void net_event(struct XenDevice *xendev)
+static void net_event(struct XenLegacyDevice *xendev)
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
     net_tx_packets(netdev);
     qemu_flush_queued_packets(qemu_get_queue(netdev->nic));
 }
 
-static int net_free(struct XenDevice *xendev)
+static int net_free(struct XenLegacyDevice *xendev)
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
 

hw/usb/xen-usb.c

@@ -27,7 +27,7 @@
 #include "qemu/option.h"
 #include "hw/sysbus.h"
 #include "hw/usb.h"
-#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen-legacy-backend.h"
 #include "monitor/qdev.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
@@ -99,7 +99,7 @@ struct usbback_hotplug {
 };
 
 struct usbback_info {
-    struct XenDevice         xendev;  /* must be first */
+    struct XenLegacyDevice         xendev;  /* must be first */
     USBBus                   bus;
     void                     *urb_sring;
     void                     *conn_sring;
@@ -142,7 +142,7 @@ static int usbback_gnttab_map(struct usbback_req *usbback_req)
     unsigned int nr_segs, i, prot;
     uint32_t ref[USBIF_MAX_SEGMENTS_PER_REQUEST];
     struct usbback_info *usbif = usbback_req->usbif;
-    struct XenDevice *xendev = &usbif->xendev;
+    struct XenLegacyDevice *xendev = &usbif->xendev;
     struct usbif_request_segment *seg;
     void *addr;
 
@@ -220,7 +220,7 @@ static int usbback_gnttab_map(struct usbback_req *usbback_req)
 
 static int usbback_init_packet(struct usbback_req *usbback_req)
 {
-    struct XenDevice *xendev = &usbback_req->usbif->xendev;
+    struct XenLegacyDevice *xendev = &usbback_req->usbif->xendev;
     USBPacket *packet = &usbback_req->packet;
     USBDevice *dev = usbback_req->stub->dev;
     USBEndpoint *ep;
@@ -279,7 +279,7 @@ static void usbback_do_response(struct usbback_req *usbback_req, int32_t status,
 {
     struct usbback_info *usbif;
     struct usbif_urb_response *res;
-    struct XenDevice *xendev;
+    struct XenLegacyDevice *xendev;
     unsigned int notify;
 
     usbif = usbback_req->usbif;
@@ -824,7 +824,7 @@ static void usbback_process_port(struct usbback_info *usbif, unsigned port)
     g_free(busid);
 }
 
-static void usbback_disconnect(struct XenDevice *xendev)
+static void usbback_disconnect(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
     unsigned int i;
@@ -853,7 +853,7 @@ static void usbback_disconnect(struct XenDevice *xendev)
     TR_BUS(xendev, "finished\n");
 }
 
-static int usbback_connect(struct XenDevice *xendev)
+static int usbback_connect(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
     struct usbif_urb_sring *urb_sring;
@@ -913,7 +913,8 @@ static int usbback_connect(struct XenDevice *xendev)
     return 0;
 }
 
-static void usbback_backend_changed(struct XenDevice *xendev, const char *node)
+static void usbback_backend_changed(struct XenLegacyDevice *xendev,
+                                    const char *node)
 {
     struct usbback_info *usbif;
     unsigned int i;
@@ -926,7 +927,7 @@ static void usbback_backend_changed(struct XenDevice *xendev, const char *node)
     }
 }
 
-static int usbback_init(struct XenDevice *xendev)
+static int usbback_init(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
 
@@ -1005,7 +1006,7 @@ static USBPortOps xen_usb_port_ops = {
 static USBBusOps xen_usb_bus_ops = {
 };
 
-static void usbback_alloc(struct XenDevice *xendev)
+static void usbback_alloc(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
     USBPort *p;
@@ -1027,7 +1028,7 @@ static void usbback_alloc(struct XenDevice *xendev)
     usbif->bh = qemu_bh_new(usbback_bh, usbif);
 }
 
-static int usbback_free(struct XenDevice *xendev)
+static int usbback_free(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
     struct usbback_req *usbback_req;
@@ -1066,7 +1067,7 @@ static int usbback_free(struct XenDevice *xendev)
     return 0;
 }
 
-static void usbback_event(struct XenDevice *xendev)
+static void usbback_event(struct XenLegacyDevice *xendev)
 {
     struct usbback_info *usbif;
 

hw/xen/Makefile.objs

@@ -1,5 +1,5 @@
 # xen backend driver support
-common-obj-$(CONFIG_XEN) += xen_backend.o xen_devconfig.o xen_pvdev.o xen-common.o
+common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-common.o xen-bus.o xen-bus-helper.o xen-backend.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_graphics.o xen_pt_msi.o

hw/xen/trace-events

@@ -12,3 +12,29 @@ xen_unmap_portio_range(uint32_t id, uint64_t start_addr, uint64_t end_addr) "id:
 xen_map_pcidev(uint32_t id, uint8_t bus, uint8_t dev, uint8_t func) "id: %u bdf: %02x.%02x.%02x"
 xen_unmap_pcidev(uint32_t id, uint8_t bus, uint8_t dev, uint8_t func) "id: %u bdf: %02x.%02x.%02x"
 xen_domid_restrict(int err) "err: %u"
+
+# include/hw/xen/xen-bus.c
+xen_bus_realize(void) ""
+xen_bus_unrealize(void) ""
+xen_bus_enumerate(void) ""
+xen_bus_type_enumerate(const char *type) "type: %s"
+xen_bus_backend_create(const char *type, const char *path) "type: %s path: %s"
+xen_bus_add_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s"
+xen_bus_remove_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s"
+xen_bus_watch(const char *token) "token: %s"
+xen_device_realize(const char *type, char *name) "type: %s name: %s"
+xen_device_unrealize(const char *type, char *name) "type: %s name: %s"
+xen_device_backend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
+xen_device_backend_online(const char *type, char *name, bool online) "type: %s name: %s -> %u"
+xen_device_backend_changed(const char *type, char *name) "type: %s name: %s"
+xen_device_frontend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
+xen_device_frontend_changed(const char *type, char *name) "type: %s name: %s"
+xen_device_unplug(const char *type, char *name) "type: %s name: %s"
+
+# include/hw/xen/xen-bus-helper.c
+xs_node_create(const char *node) "%s"
+xs_node_destroy(const char *node) "%s"
+xs_node_vprintf(char *path, char *value) "%s %s"
+xs_node_vscanf(char *path, char *value) "%s %s"
+xs_node_watch(char *path) "%s"
+xs_node_unwatch(char *path) "%s"

hw/xen/xen-backend.c

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2018  Citrix Systems Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "hw/xen/xen-backend.h"
+#include "hw/xen/xen-bus.h"
+
+typedef struct XenBackendImpl {
+    const char *type;
+    XenBackendDeviceCreate create;
+    XenBackendDeviceDestroy destroy;
+} XenBackendImpl;
+
+struct XenBackendInstance {
+    QLIST_ENTRY(XenBackendInstance) entry;
+    const XenBackendImpl *impl;
+    XenBus *xenbus;
+    char *name;
+    XenDevice *xendev;
+};
+
+static GHashTable *xen_backend_table_get(void)
+{
+    static GHashTable *table;
+
+    if (table == NULL) {
+        table = g_hash_table_new(g_str_hash, g_str_equal);
+    }
+
+    return table;
+}
+
+static void xen_backend_table_add(XenBackendImpl *impl)
+{
+    g_hash_table_insert(xen_backend_table_get(), (void *)impl->type, impl);
+}
+
+static const XenBackendImpl *xen_backend_table_lookup(const char *type)
+{
+    return g_hash_table_lookup(xen_backend_table_get(), type);
+}
+
+void xen_backend_register(const XenBackendInfo *info)
+{
+    XenBackendImpl *impl = g_new0(XenBackendImpl, 1);
+
+    g_assert(info->type);
+
+    if (xen_backend_table_lookup(info->type)) {
+        error_report("attempt to register duplicate Xen backend type '%s'",
+                     info->type);
+        abort();
+    }
+
+    if (!info->create) {
+        error_report("backend type '%s' has no creator", info->type);
+        abort();
+    }
+
+    impl->type = info->type;
+    impl->create = info->create;
+    impl->destroy = info->destroy;
+
+    xen_backend_table_add(impl);
+}
+
+static QLIST_HEAD(, XenBackendInstance) backend_list;
+
+static void xen_backend_list_add(XenBackendInstance *backend)
+{
+    QLIST_INSERT_HEAD(&backend_list, backend, entry);
+}
+
+static XenBackendInstance *xen_backend_list_find(XenDevice *xendev)
+{
+    XenBackendInstance *backend;
+
+    QLIST_FOREACH(backend, &backend_list, entry) {
+        if (backend->xendev == xendev) {
+            return backend;
+        }
+    }
+
+    return NULL;
+}
+
+static void xen_backend_list_remove(XenBackendInstance *backend)
+{
+    QLIST_REMOVE(backend, entry);
+}
+
+void xen_backend_device_create(XenBus *xenbus, const char *type,
+                               const char *name, QDict *opts, Error **errp)
+{
+    const XenBackendImpl *impl = xen_backend_table_lookup(type);
+    XenBackendInstance *backend;
+    Error *local_error = NULL;
+
+    if (!impl) {
+        return;
+    }
+
+    backend = g_new0(XenBackendInstance, 1);
+    backend->xenbus = xenbus;
+    backend->name = g_strdup(name);
+
+    impl->create(backend, opts, &local_error);
+    if (local_error) {
+        error_propagate(errp, local_error);
+        g_free(backend->name);
+        g_free(backend);
+        return;
+    }
+
+    backend->impl = impl;
+    xen_backend_list_add(backend);
+}
+
+XenBus *xen_backend_get_bus(XenBackendInstance *backend)
+{
+    return backend->xenbus;
+}
+
+const char *xen_backend_get_name(XenBackendInstance *backend)
+{
+    return backend->name;
+}
+
+void xen_backend_set_device(XenBackendInstance *backend,
+                            XenDevice *xendev)
+{
+    g_assert(!backend->xendev);
+    backend->xendev = xendev;
+}
+
+XenDevice *xen_backend_get_device(XenBackendInstance *backend)
+{
+    return backend->xendev;
+}
+
+
+bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp)
+{
+    XenBackendInstance *backend = xen_backend_list_find(xendev);
+    const XenBackendImpl *impl;
+
+    if (!backend) {
+        return false;
+    }
+
+    impl = backend->impl;
+    impl->destroy(backend, errp);
+
+    xen_backend_list_remove(backend);
+    g_free(backend->name);
+    g_free(backend);
+
+    return true;
+}