Re: [Qemu-devel] [PATCH 3/3] pci: add reserved slot check to do_pci_register_device()

[Marcel Apfelbaum]

On 07/07/2017 10:44, Mark Cave-Ayland wrote:

Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---
  hw/pci/pci.c |   21 ++++++++++++++++++---
  1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 239161e..9dece2a 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -961,6 +961,15 @@ static bool pci_bus_devfn_available(PCIBus *bus, int devfn)
      }
  }

Hi Mark,

+static bool pci_bus_devfn_reserved(PCIBus *bus, int devfn)
+{
+    if (bus->dev_reserved_mask & (1UL << PCI_SLOT(devfn))) {

Looking at this code maybe we should rename the field to
"slot_mask"? Only a suggestion.

+        return true;
+    } else {
+        return false;
+    }
+}
+ >   /* -1 for devfn means auto assign */
  static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
                                           const char *name, int devfn,
@@ -984,14 +993,20 @@ static PCIDevice *do_pci_register_device(PCIDevice 
*pci_dev, PCIBus *bus,
      if (devfn < 0) {
          for(devfn = bus->devfn_min ; devfn < ARRAY_SIZE(bus->devices);
              devfn += PCI_FUNC_MAX) {
-            if (pci_bus_devfn_available(bus, devfn)) {
+            if (pci_bus_devfn_available(bus, devfn) &&
+                   !pci_bus_devfn_reserved(bus, devfn)) {
                  goto found;
              }
          }
-        error_setg(errp, "PCI: no slot/function available for %s, all in use",
-                   name);
+        error_setg(errp, "PCI: no slot/function available for %s, all in use "
+                   "or reserved", name);

I wouldn't combine slot available/reserved, maybe check for reserved
before "available"?

          return NULL;
      found: ;
+    } else if (pci_bus_devfn_reserved(bus, devfn)) {
+        error_setg(errp, "PCI: slot %d function %d not available for %s,"
+                   " reserved",
+                   PCI_SLOT(devfn), PCI_FUNC(devfn), name);
+        return NULL;
      } else if (!pci_bus_devfn_available(bus, devfn)) {
          error_setg(errp, "PCI: slot %d function %d not available for %s,"
                     " in use by %s",

Thanks for the patches!
Marcel