From d5f89735e06e4033abdb04a62d713860742d43f8 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@suse.com>
Date: Tue, 29 Mar 2016 07:29:19 +0200
Subject: [PATCH] libxl: check for dynamic device model start required

Add a service routine checking whether a device model must be started
after adding a device to a domain.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
 tools/libxl/libxl.c          | 12 ++++++++++++
 tools/libxl/libxl_dm.c       | 22 ++++++++++++++++++++++
 tools/libxl/libxl_internal.h |  3 +++
 tools/libxl/libxl_pci.c      |  3 +++
 tools/libxl/libxl_pvusb.c    |  6 ++++++
 5 files changed, 46 insertions(+)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 1ac7848677..56179008bf 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2104,6 +2104,9 @@ void libxl__device_vtpm_add(libxl__egc *egc, uint32_t domid,
         if (rc) goto out;
 
         DEVICE_ADD(vtpm, vtpms, domid, &vtpm_saved, COMPARE_DEVID, &d_config);
+
+        rc = libxl__dm_check_start(gc, &d_config, domid);
+        if (rc) goto out;
     }
 
     for (;;) {
@@ -2410,6 +2413,9 @@ static void device_disk_add(libxl__egc *egc, uint32_t domid,
         if (rc) goto out;
 
         DEVICE_ADD(disk, disks, domid, &disk_saved, COMPARE_DISK, &d_config);
+
+        rc = libxl__dm_check_start(gc, &d_config, domid);
+        if (rc) goto out;
     }
 
     for (;;) {
@@ -2982,6 +2988,9 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid, libxl_device_disk *disk,
 
     DEVICE_ADD(disk, disks, domid, &disk_saved, COMPARE_DISK, &d_config);
 
+    rc = libxl__dm_check_start(gc, &d_config, domid);
+    if (rc) goto out;
+
     if (dm_ver == LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN) {
         rc = libxl__qmp_insert_cdrom(gc, domid, disk);
         if (rc) goto out;
@@ -3484,6 +3493,9 @@ void libxl__device_nic_add(libxl__egc *egc, uint32_t domid,
         if (rc) goto out;
 
         DEVICE_ADD(nic, nics, domid, &nic_saved, COMPARE_DEVID, &d_config);
+
+        rc = libxl__dm_check_start(gc, &d_config, domid);
+        if (rc) goto out;
     }
 
     for (;;) {
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index bc043fe9fc..ba45ba5a4f 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -2387,6 +2387,28 @@ int libxl__dm_active(libxl__gc *gc, uint32_t domid)
     return pid != NULL;
 }
 
+int libxl__dm_check_start(libxl__gc *gc, libxl_domain_config *d_config,
+                          uint32_t domid)
+{
+    int rc;
+
+    if (libxl__dm_active(gc, domid))
+        return 0;
+
+    rc = libxl__need_xenpv_qemu(gc, d_config);
+    if (rc < 0)
+        goto out;
+
+    if (!rc)
+        return 0;
+
+    LOG(ERROR, "device model required but not running");
+    rc = ERROR_FAIL;
+
+out:
+    return rc;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index eaa150d5ea..fb4d225944 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1626,6 +1626,9 @@ _hidden bool libxl__query_qemu_backend(libxl__gc *gc,
                                        const char *type,
                                        bool def);
 _hidden int libxl__dm_active(libxl__gc *gc, uint32_t domid);
+_hidden int libxl__dm_check_start(libxl__gc *gc,
+                                  libxl_domain_config *d_config,
+                                  uint32_t domid);
 
 /*
  * This function will fix reserved device memory conflict
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index dc10cb7668..300fd4dbac 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -169,6 +169,9 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, uint32_t domid, libxl_d
 
     DEVICE_ADD(pci, pcidevs, domid, &pcidev_saved, COMPARE_PCI, &d_config);
 
+    rc = libxl__dm_check_start(gc, &d_config, domid);
+    if (rc) goto out;
+
     for (;;) {
         rc = libxl__xs_transaction_start(gc, &t);
         if (rc) goto out;
diff --git a/tools/libxl/libxl_pvusb.c b/tools/libxl/libxl_pvusb.c
index 68e5673c51..c9b7c4a799 100644
--- a/tools/libxl/libxl_pvusb.c
+++ b/tools/libxl/libxl_pvusb.c
@@ -145,6 +145,9 @@ static int libxl__device_usbctrl_add_xenstore(libxl__gc *gc, uint32_t domid,
         DEVICE_ADD(usbctrl, usbctrls, domid, &usbctrl_saved,
                    COMPARE_USBCTRL, &d_config);
 
+        rc = libxl__dm_check_start(gc, &d_config, domid);
+        if (rc) goto out;
+
         if (usbctrl->type == LIBXL_USBCTRL_TYPE_QUSB) {
             if (!libxl__query_qemu_backend(gc, domid, usbctrl->backend_domid,
                                            "qusb", false)) {
@@ -969,6 +972,9 @@ static int libxl__device_usbdev_add_xenstore(libxl__gc *gc, uint32_t domid,
 
         DEVICE_ADD(usbdev, usbdevs, domid, &usbdev_saved,
                    COMPARE_USB, &d_config);
+
+        rc = libxl__dm_check_start(gc, &d_config, domid);
+        if (rc) goto out;
     }
 
     for (;;) {
-- 
2.30.2