Re: [Qemu-devel] [PATCH 00/15] qdev: make reset semantics more clear and consistent, reset qbuses under virtio devices

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jan 09, 2013 at 12:12:55PM +0100, Paolo Bonzini wrote:
> Il 09/01/2013 12:09, Michael S. Tsirkin ha scritto:
> > On Wed, Jan 09, 2013 at 11:53:00AM +0100, Paolo Bonzini wrote:
> >> Il 09/01/2013 11:22, Michael S. Tsirkin ha scritto:
> >>>> It's possible.  I'll move the SCSI bus away from qdev reset.
> >>>> Anthony/Michael, can you help doing the same with PCIDevice?  And
> >>>> perhaps Peter and Andreas with sysbus?
> >>>
> >>> I'm not sure what would you like to change with PCIDevice.
> >>
> >> Replace the DeviceState reset method with one in PCIDevice, and call it
> >> from the PCI bus reset.
> >>
> >> Paolo
> > 
> > You are talking about the call to qdev_reset_all(&dev->qdev)
> > in pci_device_reset
> 
> Yes.
> 
> > , and you want to detect, there, that device is a bridge
> > and replace qdev_reset_all(&dev->qdev) with cast and call to pci_bus_reset
> > for the secondary bus?
> 
> The bridge would call pci_bus_reset for its secondary bus in the
> PCIDevice reset method.
> 
> I.e. all bus navigation would have to be explicit in the reset
> callbacks.  I'm going to do that for the SCSI HBAs.
> 
> Paolo

OK you mean like this this? Completely untested - if you
and Anthony think we need this change please let me know
and I'll test and repost.

-->

pci: make secondary bus reset explicit

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

---

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 94840c4..ad81040 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -172,7 +172,7 @@ void pci_device_reset(PCIDevice *dev)
 {
     int r;
 
-    qdev_reset_all(&dev->qdev);
+    device_reset(&dev->qdev);
 
     dev->irq_state = 0;
     pci_update_irq_status(dev);
diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
index 995842a..a08b479 100644
--- a/hw/pci/pci_bridge.c
+++ b/hw/pci/pci_bridge.c
@@ -258,10 +258,12 @@ void pci_bridge_disable_base_limit(PCIDevice *dev)
     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
 }
 
-/* reset bridge specific configuration registers */
+/* reset bridge specific configuration registers.
+ * Propagate reset on the secondary bus. */
 void pci_bridge_reset(DeviceState *qdev)
 {
     PCIDevice *dev = PCI_DEVICE(qdev);
+    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
     uint8_t *conf = dev->config;
 
     conf[PCI_PRIMARY_BUS] = 0;
@@ -295,6 +297,8 @@ void pci_bridge_reset(DeviceState *qdev)
     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
 
     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
+
+    pci_bus_reset(&br->sec_bus);
 }
 
 /* default qdev initialization function for PCI-to-PCI bridge */