File 5d976da3-libxl-attach-PCI-device-to-qemu-only-after-setting-pciback-pcifront.patch of Package xen.16819

Subject: libxl: attach PCI device to qemu only after setting pciback/pcifront
From: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com Tue Oct 1 05:24:19 2019 +0100
Date: Fri Oct 4 17:04:51 2019 +0100:
Git: ac2726ecc156fdc7434ca0211022f3124ecfe50a

When qemu is running in stubdomain, handling "pci-ins" command will fail
if pcifront is not initialized already. Fix this by sending such command
only after confirming that pciback/front is running.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>

---
 tools/libxl/libxl_pci.c | 9 +++++++++
 1 file changed, 9 insertions(+)

--- xen-4.12.2-testing.orig/tools/libxl/libxl_pci.c
+++ xen-4.12.2-testing/tools/libxl/libxl_pci.c
@@ -1214,6 +1214,7 @@ int libxl__device_pci_add(libxl__gc *gc,
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
     unsigned int orig_vdev, pfunc_mask;
+    char *be_path;
     libxl_device_pci *assigned;
     int num_assigned, i, rc;
     int stubdomid = 0;
@@ -1268,6 +1269,14 @@ int libxl__device_pci_add(libxl__gc *gc,
         rc = do_pci_add(gc, stubdomid, &pcidev_s, 0);
         if ( rc )
             goto out;
+        /* wait for the device actually being connected, otherwise device model
+         * running there will fail to find the device */
+        be_path = libxl__sprintf(gc, "%s/backend/pci/%d/0",
+                libxl__xs_get_dompath(gc, 0), stubdomid);
+        rc = libxl__wait_for_backend(gc, be_path,
+                    GCSPRINTF("%d", XenbusStateConnected));
+        if ( rc )
+            goto out;
     }
 
     orig_vdev = pcidev->vdevfn & ~7U;