Re: [Qemu-devel] Bug#688964: qemu-kvm: Fedora 17 guest hangs on boot with soft lockup in udevd

[Michael Tokarev <mjt@tls.msk.ru>]

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On 27.09.2012 22:28, Jan Kiszka wrote:
[]
>> --- a/hw/intel-hda.c
>> +++ b/hw/intel-hda.c
>> @@ -1107,6 +1107,9 @@ static void intel_hda_reset(DeviceState *dev)
>>      DeviceState *qdev;
>>      HDACodecDevice *cdev;
>>
>> +    if (d->msi) {
>> +        msi_reset(&d->pci);
>> +    }
>>      intel_hda_regs_reset(d);
>>      d->wall_base_ns = qemu_get_clock_ns(vm_clock);
>>
>> which is exactly about this hda thing.  I'm CC'ing relevant
>> people here.
> 
> I suppose we are resetting the MSI configuration also in cases here
> where only the HDA internals are supposed to be reset (when called from
> intel_hda_set_g_ctl).

Hmm.  I was looking at this code already (but i don't know the machinery
anyway).  Here it is (I addedd two printfs in obvious places):

in intel_hda_reset
calling intel_hda_reset from intel_hda_set_g_ctl
in intel_hda_reset
(at this time it hangs in guest).

The following patch fixes it.  Is it correct? :)

/mjt

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diff --git a/hw/intel-hda.c b/hw/intel-hda.c
index e38861e..fdd7eeb 100644
--- a/hw/intel-hda.c
+++ b/hw/intel-hda.c
@@ -199,7 +199,7 @@ struct IntelHDAReg {
     void       (*rhandler)(IntelHDAState *d, const IntelHDAReg *reg);
 };
 
-static void intel_hda_reset(DeviceState *dev);
+static void intel_hda_reset_dev(DeviceState *dev);
 
 /* --------------------------------------------------------------------- */
 
@@ -500,7 +500,7 @@ static void intel_hda_notify_codecs(IntelHDAState *d, uint32_t stream, bool runn
 static void intel_hda_set_g_ctl(IntelHDAState *d, const IntelHDAReg *reg, uint32_t old)
 {
     if ((d->g_ctl & ICH6_GCTL_RESET) == 0) {
-        intel_hda_reset(&d->pci.qdev);
+        intel_hda_reset_dev(&d->pci.qdev);
     }
 }
 
@@ -1101,15 +1101,12 @@ static const MemoryRegionOps intel_hda_mmio_ops = {
 
 /* --------------------------------------------------------------------- */
 
-static void intel_hda_reset(DeviceState *dev)
+static void intel_hda_reset_dev(DeviceState *dev)
 {
     IntelHDAState *d = DO_UPCAST(IntelHDAState, pci.qdev, dev);
     DeviceState *qdev;
     HDACodecDevice *cdev;
 
-    if (d->msi) {
-        msi_reset(&d->pci);
-    }
     intel_hda_regs_reset(d);
     d->wall_base_ns = qemu_get_clock_ns(vm_clock);
 
@@ -1122,6 +1119,15 @@ static void intel_hda_reset(DeviceState *dev)
     intel_hda_update_irq(d);
 }
 
+static void intel_hda_reset(DeviceState *dev)
+{
+    IntelHDAState *d = DO_UPCAST(IntelHDAState, pci.qdev, dev);
+    if (d->msi) {
+        msi_reset(&d->pci);
+    }
+    intel_hda_reset_dev(dev);
+}
+
 static int intel_hda_init(PCIDevice *pci)
 {
     IntelHDAState *d = DO_UPCAST(IntelHDAState, pci, pci);