pci_find_primary_bus() only has one user, in pc_xen_hvm_init().  That's
inside the machine construction code, so it already has easy access to the
machine's primary PCI bus.

Get it directly, and thereby remove pci_find_primary_bus().  This removes
one of only a handful of users of the ugly pci_host_bridges global.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/i386/pc_piix.c    |  8 ++------
 hw/pci/pci.c         | 16 ----------------
 include/hw/pci/pci.h |  1 -
 3 files changed, 2 insertions(+), 23 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 5e47528993..2febd0e136 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -394,7 +394,7 @@ static void pc_xen_hvm_init_pci(MachineState *machine)
 
 static void pc_xen_hvm_init(MachineState *machine)
 {
-    PCIBus *bus;
+    PCMachineState *pcms = PC_MACHINE(machine);
 
     if (!xen_enabled()) {
         error_report("xenfv machine requires the xen accelerator");
@@ -402,11 +402,7 @@ static void pc_xen_hvm_init(MachineState *machine)
     }
 
     pc_xen_hvm_init_pci(machine);
-
-    bus = pci_find_primary_bus();
-    if (bus != NULL) {
-        pci_create_simple(bus, -1, "xen-platform");
-    }
+    pci_create_simple(pcms->bus, -1, "xen-platform");
 }
 #endif
 
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index cd4d9d7ecd..ab76c4f3f1 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -324,22 +324,6 @@ static void pci_host_bus_register(DeviceState *host)
     QLIST_INSERT_HEAD(&pci_host_bridges, host_bridge, next);
 }
 
-PCIBus *pci_find_primary_bus(void)
-{
-    PCIBus *primary_bus = NULL;
-    PCIHostState *host;
-
-    QLIST_FOREACH(host, &pci_host_bridges, next) {
-        if (primary_bus) {
-            /* We have multiple root buses, refuse to select a primary */
-            return NULL;
-        }
-        primary_bus = host->bus;
-    }
-
-    return primary_bus;
-}
-
 PCIBus *pci_device_root_bus(const PCIDevice *d)
 {
     PCIBus *bus = pci_get_bus(d);
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 50034157fd..867b1ee175 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -519,7 +519,6 @@ void pci_for_each_bus(PCIBus *bus,
     pci_for_each_bus_depth_first(bus, NULL, fn, opaque);
 }
 
-PCIBus *pci_find_primary_bus(void);
 PCIBus *pci_device_root_bus(const PCIDevice *d);
 const char *pci_root_bus_path(PCIDevice *dev);
 PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn);
-- 
2.14.3

On 29/11/2017 10:46, David Gibson wrote:
> pci_find_primary_bus() only has one user, in pc_xen_hvm_init().  That's
> inside the machine construction code, so it already has easy access to the
> machine's primary PCI bus.
> 
> Get it directly, and thereby remove pci_find_primary_bus().  This removes
> one of only a handful of users of the ugly pci_host_bridges global.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>   hw/i386/pc_piix.c    |  8 ++------
>   hw/pci/pci.c         | 16 ----------------
>   include/hw/pci/pci.h |  1 -
>   3 files changed, 2 insertions(+), 23 deletions(-)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 5e47528993..2febd0e136 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -394,7 +394,7 @@ static void pc_xen_hvm_init_pci(MachineState *machine)
>   
>   static void pc_xen_hvm_init(MachineState *machine)
>   {
> -    PCIBus *bus;
> +    PCMachineState *pcms = PC_MACHINE(machine);
>   
>       if (!xen_enabled()) {
>           error_report("xenfv machine requires the xen accelerator");
> @@ -402,11 +402,7 @@ static void pc_xen_hvm_init(MachineState *machine)
>       }
>   
>       pc_xen_hvm_init_pci(machine);
> -
> -    bus = pci_find_primary_bus();
> -    if (bus != NULL) {
> -        pci_create_simple(bus, -1, "xen-platform");
> -    }
> +    pci_create_simple(pcms->bus, -1, "xen-platform");
>   }
>   #endif
>   
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index cd4d9d7ecd..ab76c4f3f1 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -324,22 +324,6 @@ static void pci_host_bus_register(DeviceState *host)
>       QLIST_INSERT_HEAD(&pci_host_bridges, host_bridge, next);
>   }
>   
> -PCIBus *pci_find_primary_bus(void)
> -{
> -    PCIBus *primary_bus = NULL;
> -    PCIHostState *host;
> -
> -    QLIST_FOREACH(host, &pci_host_bridges, next) {
> -        if (primary_bus) {
> -            /* We have multiple root buses, refuse to select a primary */
> -            return NULL;
> -        }
> -        primary_bus = host->bus;
> -    }
> -
> -    return primary_bus;
> -}
> -
>   PCIBus *pci_device_root_bus(const PCIDevice *d)
>   {
>       PCIBus *bus = pci_get_bus(d);
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 50034157fd..867b1ee175 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -519,7 +519,6 @@ void pci_for_each_bus(PCIBus *bus,
>       pci_for_each_bus_depth_first(bus, NULL, fn, opaque);
>   }
>   
> -PCIBus *pci_find_primary_bus(void);
>   PCIBus *pci_device_root_bus(const PCIDevice *d);
>   const char *pci_root_bus_path(PCIDevice *dev);
>   PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn);
> 

Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>

Thanks,
Marcel

On Wed, Nov 29, 2017 at 07:46:28PM +1100, David Gibson wrote:
> pci_find_primary_bus() only has one user, in pc_xen_hvm_init().  That's
> inside the machine construction code, so it already has easy access to the
> machine's primary PCI bus.
> 
> Get it directly, and thereby remove pci_find_primary_bus().  This removes
> one of only a handful of users of the ugly pci_host_bridges global.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu