Re: [XTF 4/4] setup: Setup PV console for HVM guests on xen >4.2

["Wieczorkiewicz, Pawel" <wipawel@xxxxxxxxx>]

> On 16. Apr 2020, at 12:36, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
> 
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> On 16/04/2020 10:41, Pawel Wieczorkiewicz wrote:
>> @@ -272,9 +274,23 @@ void arch_setup(void)
>> 
>>     init_hypercalls();
>> 
>> -    if ( !is_initdomain() )
>> +    xen_version = hypercall_xen_version(XENVER_version, NULL);
>> +    if ( version )
>> +        *version = xen_version;
>> +
>> +    /*
>> +     * The setup_pv_console function registers a writing function
>> +     * that makes hvm guests crash on Xen 4.2
> 
> This comment in particular is rather concerning.  Even if there is a
> configuration issue in 4.2 stopping the PV console from being wired up
> properly, nothing involved in transmitting on the console should crash
> the guest.
> 

I am again a little short on details here. Maybe Paul could chime in.
But, I vagualy remember it was something about the init_pv_console()’s:

    if ( port >= (sizeof(shared_info.evtchn_pending) * CHAR_BIT) )
        panic("evtchn %u out of evtchn_pending[] range\n", port);

> ~Andrew


Best Regards,
Pawel Wieczorkiewicz
wipawel@xxxxxxxxxx



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