[PATCH v2] device-assignment: Better fd tracking

[Alex Williamson <alex.williamson@redhat.com>]

Commit 909bfdba fixed a hole with not closing resource file descriptors
but we need to be more careful about tracking which are real fds,
otherwise we might close fd 0, which doesn't work out so well for stdio.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

 v2: fix qemu style braces

 hw/device-assignment.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 48ac73c..de9470c 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -694,6 +694,7 @@ again:
 
         rp = dev->regions + r;
         rp->valid = 0;
+        rp->resource_fd = -1;
         size = end - start + 1;
         flags &= IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
         if (size == 0 || (flags & ~IORESOURCE_PREFETCH) == 0)
@@ -785,7 +786,9 @@ static void free_assigned_device(AssignedDevice *dev)
                         fprintf(stderr,
 				"Failed to unmap assigned device region: %s\n",
 				strerror(errno));
-                    close(pci_region->resource_fd);
+                    if (pci_region->resource_fd >= 0) {
+                        close(pci_region->resource_fd);
+                    }
                 }
 	    }
         }
@@ -793,9 +796,8 @@ static void free_assigned_device(AssignedDevice *dev)
         if (dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX)
             assigned_dev_unregister_msix_mmio(dev);
 
-        if (dev->real_device.config_fd) {
+        if (dev->real_device.config_fd >= 0) {
             close(dev->real_device.config_fd);
-            dev->real_device.config_fd = 0;
         }
 
 #ifdef KVM_CAP_IRQ_ROUTING
@@ -1415,7 +1417,7 @@ static int assigned_initfn(struct PCIDevice *pci_dev)
 
     if (!dev->host.seg && !dev->host.bus && !dev->host.dev && !dev->host.func) {
         error_report("pci-assign: error: no host device specified");
-        goto out;
+        return -1;
     }
 
     if (get_real_device(dev, dev->host.seg, dev->host.bus,