Re: Multiple issues with event channel on Xen on ARM

[Julien Grall <julien.grall@linaro.org>]

On 05/02/14 10:09, David Vrabel wrote:
> On 04/02/14 23:18, Julien Grall wrote:
>>
>> Now, if I'm using Linux 3.14-rc1 as guest and trying to destroy the domain,
>> I get this following Xen trace:
>>
>> (XEN) Assertion 'slot >= 0 && slot < DOMHEAP_ENTRIES' failed, line 334, file mm.c
> [...]
>> (XEN) Xen call trace:
>> (XEN)    [<0023f7d0>] __bug+0x28/0x44 (PC)
>> (XEN)    [<0023f7d0>] __bug+0x28/0x44 (LR)
>> (XEN)    [<00247d6c>] domain_page_map_to_mfn+0x50/0xb4
>> (XEN)    [<0020b17c>] unmap_guest_page+0x20/0x54
>> (XEN)    [<0020b1d0>] cleanup_control_block+0x20/0x34
>> (XEN)    [<0020bd3c>] evtchn_fifo_destroy+0x2c/0x6c
>> (XEN)    [<0020b024>] evtchn_destroy+0x1a8/0x1b0
>> (XEN)    [<00207f80>] domain_kill+0x60/0x128
>> (XEN)    [<00206050>] do_domctl+0xa7c/0x1104
>> (XEN)    [<0024cee0>] do_trap_hypervisor+0xad8/0xd78
>> (XEN)    [<0024f6d0>] return_from_trap+0/0x4
>
> This is because ARM's domain_page_map_to_mfn() doesn't work with pages
> mapped with map_domain_page_global() which uses vmap().
>
> x86's implementation has
>
>      if ( va >= VMAP_VIRT_START && va < VMAP_VIRT_END )
>      {
>          pl1e = virt_to_xen_l1e(va);
>          BUG_ON(!pl1e);
>      }
>      // ...
>      return l1e_get_pfn(*pl1e);
>
> So I think ARM's needs something similar.

Thanks David, I will take a look on it. For the first bug (in Linux) do 
you have any input?

Regards,

-- 
Julien Grall