Re: pvops: AHCI problems with SB600

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Sep 22, 2009 at 11:00:23AM +0200, Patrick Scharrenberg wrote:
> Konrad Rzeszutek Wilk wrote:
> > Ooooh. Can you give some more details on the hardware flavor? CPU? Memory?
> Its an AMD system on an ASUS M2A-VM mainboard with an Athlon 64 X2 CPU
> and 8GB of memory.
> 
> > What happens if you use dom0_mem=max:512MB or pass in 'irqpoll' to the
> > Linux kernel?
> irqpoll does not change anything but the memory limit does the trick.
> The system then boots fine, I attached the dmesg log.

Patrick,

Lets try a couple of more options, if this isn't too much of a trouble?
Mainly change the dom0_mem=max:512MB to dom0_mem=max:4GB and then dom0_mem=max:6GB.

You ought to have no trouble at 4GB. 6GB will fail if this is a DMA related
issue.

> Since the netconsole now also works, I assume some kind of IRQ problem
> which is strengthened by the fact, that the keyboard didn't work either
> (for scrolling and searching for problems) without the memory limit option.

The log says:
> [    2.209240] ehci_hcd 0000:00:13.5: applying AMD SB600/SB700 USB freeze workaround

That might be the reason your keyboard didn't work. Unless your keyboard is PS/2?

> 
> > OK. I need the kernel boot log to figure out what might be a potential problem.
> > Let's try to get your netconsole working or your serial console? Does this
> > machine even have a serial port? Maybe you can use that to capture the kernel
> > output?
> 
> I attached the bootlog with the 512 memory-limit enabled and the xen dmesg.

Thank you.
> 
> Unfortunately I have to drive 200km to install a serial cable to the
> system. So if there is an IRQ problem would the serial console really
> help or would it suffer from the same irq problem?
>

If it is an IRQ problem it would probably mess up the serial console right as it
is happening. But there are ways to make Xen not do IRQs for serial console.

Here is what I have:
xen.gz  com1=115200,8n1,0xcf00,0  console=com1,vga guest_loglvl=all  dom0_mem=max:512MB

The last argument defines the IRQ. If it is set to '0' it will poll the device instead of
depending on the PCI card to provide the output. The 0xcf00 is the non-standard location
of the COM1 (most systems have that on 0x3f8 or so).

Looking at NewEgg for your motherboard it looks to _not_ have any serial output.
You would need to get a PCI Serial card for this thought.