[1.0 release work] Fix regressions found on recent KVM autotest qemu master 'sanity' jobs

[Lucas Meneghel Rodrigues <lmr@redhat.com>]

Hi guys,

As we understand that qemu is approaching 1.0, we think it's a good idea 
to share the issues we have been seeing on recent qemu.git sanity jobs:

1) Some condition is consistently making a RHEL 6.1 linux guest not able 
to bring up the network interface, causing login failures for all linux 
guest tests. This very same guest install works perfectly on qemu-kvm, 
RHEL 5 and RHEL 6.

2) The floppy regression problem which was reported some days ago on 
this mailing list still happens, Kevin did post a patch that resolves it

diff --git a/hw/dma.c b/hw/dma.c
index 8a7302a..1d3b6f1 100644
--- a/hw/dma.c
+++ b/hw/dma.c
@@ -358,6 +358,13 @@ static void DMA_run (void)
      struct dma_cont *d;
      int icont, ichan;
      int rearm = 0;
+    static int running = 0;
+
+    if (running) {
+        goto out;
+    } else {
+        running = 1;
+    }

      d = dma_controllers;

@@ -374,6 +381,8 @@ static void DMA_run (void)
          }
      }

+out:
+    running = 0;
      if (rearm)
          qemu_bh_schedule_idle(dma_bh);
  }

But still wasn't integrated upstream. As I understand, there are doubts 
whether this is a proper fix. Works with qemu-kvm.git. RHEL 5 and RHEL 6.

3) With Kevin's patch applied, windows install goes on until the first 
reboot. When it gets there, it gets stuck on the BIOS screen. The bios 
being used is the bin shipped on qemu.git's repo. So the install does 
not complete. Works with qemu-kvm.git, RHEL 5 and RHEL 6.

Those were the issues found on our 'sanity' job, which is the closest to 
a smoke test we have with KVM autotest. It simply installs one stable 
and recent linux guest, boot, simple migration, reboot, shutdown, rinse 
and repeat with the latest windows guest available. All guests use 
virtio disks and virtio network cards. It has 100% PASS rate, or very 
close to it for the other branches mentioned.

So qemu.git current state is not good, and those bugs need some work 
before 1.0 is out.

Please feel free to approach myself and Cleber on irc or email, as we 
can give you the details we have available, in case you need them.

Lucas