Bug 172406

I have duplicated this on my box, kernel-xen0-2.6.13-1.1532_FC4 &
kernel-xenU-2.6.13-1.1532_FC4.

2.6.12-1.1454_FC4.i686.rpm does boot, but networking is nonfunctional.  It seems
that although the box does transmit correctly and I can verify that by looking
at a tcpdump on another box, no packets are received.

My dmesg contains this:

e100: Intel(R) PRO/100 Network Driver, 3.4.8-k2-NAPI
e100: Copyright(c) 1999-2005 Intel Corporation
e100: eth0: e100_probe: addr 0xcfe00000, irq 16, MAC addr 00:90:27:8C:D8:19

...

e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex

...

eth0: no IPv6 routers present
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex
eth0: no IPv6 routers present
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex
eth0: no IPv6 routers present
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex
eth0: no IPv6 routers present
device eth0 entered promiscuous mode
NETDEV WATCHDOG: eth0: transmit timed out
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex

FWIW I was able to reproduce Andrew's situation and can confirm that:

kernel-xen0.i686                                         2.6.13-1.1532_FC4     
     updates-releasedkernel-xenU.i686                         2.6.13-1.1532_FC4
         updates-releasedxen.i386                                 2-20050823

... will fail to boot up with an error message of "Domain 0 allocation is too
small for kernel"

Following the advice on the Fedora Xen Quickstart
(http://www.fedoraproject.org/wiki/FedoraXenQuickstart#head-3a85df2e27189c12a2b8f045bfef3b2a759bb2ef)
I also installed:

kernel-xen0.i686                         2.6.12-1.1454_FC4      
kernel-xenU.i686                         2.6.12-1.1454_FC4      
xen.i386                                 3.0-0.20050912.fc4

... and I also have no networking, although in my case it doesn't seem to even
try to come up, and none of my prodding so far has gotten anything resembling a
network connection to come up.

I can also confirm this problem. Is there going to be an update on how to fix it?

Just like Tim I tried the kernel from the current yum repository as well as the
one suggested in the Fedora Xen Quickstart:
"2.6.12-1.1456_FC4xen0 has been known to work with the xen RPM available from
[WWW] Riel's homepage"
However, the kernel listed here is not 2.6.12-1.1456_FC4xen0 but 2.6.12-1.1454_FC4
Is somebody working on this issue?

Same problem here....
I tried the alternative kernels as in the advice of the FC Xen QS. But I had to
compile a kernelmodule for a Areca Sata controller. De building works without an
error (after fixed the asm linking). Also created a new initrd. But after a
reboot the new made kernelmodule fails. 

BTW no error for the memory problem.

*** Bug 172079 has been marked as a duplicate of this bug. ***

re comment #2: the networking issue is very different; if you can still
reproduce that, please open a separate bug for it.  (I suspect it may be the
issue described in bug 177794.)

There has been a significant rebasing of the kernel and HV images for fc5t2. 
Can you still reproduce the problem?

If so, then this sounds like a mismatch between the memory calculations in the
HV/bootloader and the kernel.  The full Xen logs would be really useful in
tracking this down; is it possible for you to capture that to a serial console?
 That, in conjunction with the normal non-xen boot logs, should let us examine
the memory maps being computed in both cases to see if there's a mismatch somewhere.

You _may_ be able to work around this by adding the "dom0_mem=...M" option to
the xen hypervisor line ("kernel=xen...") in /etc/grub.conf.  If you assign
(say) only half your physical memory to dom0 on boot, does that work?

*** Bug 170163 has been marked as a duplicate of this bug. ***

The FC5test* / rawhide kernels should fix this bug; please reopen if it recurs.