Re: [PATCH 1/3 v2] Add Directed EOI support to APIC emulation

[Gleb Natapov <gleb@redhat.com>]

On Mon, Jun 29, 2009 at 12:18:28PM +0300, Avi Kivity wrote:
> On 06/28/2009 03:15 PM, Gleb Natapov wrote:
>> Directed EOI is specified by x2APIC, but is available even when lapic is
>> in xAPIC mode.
>>
>>   #define APIC_LVT_NUM			6
>>   /* 14 is the version for Xeon and Pentium 8.4.8*/
>> -#define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1)<<  16))
>> +#define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1)<<  16) | \
>> +					 APIC_LVR_DIRECTED_EOI)
>>    
>
> Better make that depend on the x2apic cpuid bit.
>
Are you sure. It looks like this feature is independent from x2APIC. It just specified
by the same spec.

>>   static void apic_send_ipi(struct kvm_lapic *apic)
>> @@ -683,7 +686,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
>>   		break;
>>
>>   	case APIC_SPIV:
>> -		apic_set_reg(apic, APIC_SPIV, val&  0x3ff);
>> +		apic_set_reg(apic, APIC_SPIV, val&  0xfff);
>>   		if (!(val&  APIC_SPIV_APIC_ENABLED)) {
>>   			int i;
>>   			u32 lvt_val;
>>    
>
> Confused, you're adding bits 10 and 11 while APIC_SPIV_DIRECTED_EOI is  
> bit 12?
For well behaved guests it doesn't matter :) And Intel keep changing
what reserved bits are in this register. Older doc says bit 9 is a Focus
Processor bit, x2APIC doc says bit 9 is registered. So what should we do
for bit 9?

--
			Gleb.