[Lguest] Error inserting lg: Cannot allocate memory

[Stefan Hellermann]

Rusty Russell schrieb:
> On Monday 25 February 2008 09:05:49 Stefan Hellermann wrote:
>> Hello,
>>
>> I would like to try lguest, but I it doesn't work here. When I load lg it
>> says: FATAL: Error inserting lg
>> (/lib/modules/2.6.25-rc2-via/kernel/drivers/lguest/lg.ko): Cannot allocate
>> memory
>>
>> dmesg says:
>> allocation failed: out of vmalloc space - use vmalloc=<size> to increase
>> size. lguest: could not map switcher pages high
> 
> OK, I found this one (sorry for the delay, I was away).
> 
> Does this work for you?  It works for me...

I did some further testing, applying 3 patches I found in Ingo Molnars testing tree, I got
almost everything working.
To solve the TSC-problem I applied
bd860da53caf6971398fac152f21dfec56b087a4 x86: if we cannot calibrate the TSC, we panic.
86e1e14ab3cc75432806fe46dfd57f149c39e2b1 lguest: sanitize the clock

and to solve many segfaults I applied
265e3beb151ca18386281de5120552406c7920c2 x86/lguest: fix pgdir pmd index calculation

which all do what they are supposed to do :)

The only remaining problem is, that I can't get any network connection out of the guest.
This is similar to http://ozlabs.org/pipermail/lguest/2008-March/001011.html
I used a bridged networking, but the same problem.

But for the undermentioned patch I can give my first:

Tested-by: Stefan Hellermann

Thanks
Stefan
> 
> Thanks very much for your report!
> Rusty.
> ==
> Robert Bragg's 5dc331852848a38ca00a2817e5b98a1d0561b116 tightened
> (ie. fixed) the checking in __get_vm_area, and it broke lguest.
> 
> lguest should pass a valid "end" parameter, not some random constant.
> 
> Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
> Cc: Robert Bragg <robert at sixbynine.org>
> 
> diff -r f5dc1442dc61 drivers/lguest/core.c
> --- a/drivers/lguest/core.c	Tue Mar 04 14:21:38 2008 +1100
> +++ b/drivers/lguest/core.c	Tue Mar 04 21:06:41 2008 +1100
> @@ -71,9 +71,11 @@ static __init int map_switcher(void)
>  
>  	/* Now we reserve the "virtual memory area" we want: 0xFFC00000
>  	 * (SWITCHER_ADDR).  We might not get it in theory, but in practice
> -	 * it's worked so far. */
> +	 * it's worked so far.  The +1 is because __get_vm_area allocates a
> +	 * guard page, so we need space for that. */
>  	switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
> -				       VM_ALLOC, SWITCHER_ADDR, VMALLOC_END);
> +				     VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
> +				     + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
>  	if (!switcher_vma) {
>  		err = -ENOMEM;
>  		printk("lguest: could not map switcher pages high\n");