Re: [Xen-devel] [PATCH 2/4] VMX: Turn on posted interrupt bit in vmcs

["Zhang, Yang Z" <yang.z.zhang@xxxxxxxxx>]

Jan Beulich wrote on 2013-04-09:
>>>> On 09.04.13 at 08:01, Yang Zhang <yang.z.zhang@xxxxxxxxx> wrote:
>> --- a/xen/include/asm-x86/hvm/vmx/vmcs.h
>> +++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
>> @@ -73,6 +73,12 @@ struct vmx_domain {
>>      unsigned long apic_access_mfn;
>>  };
>> +struct pi_desc {
>> +    u32 pir[8];
>> +    u32 control;
>> +    u32 rsvd[7];
>> +} __attribute__ ((packed, aligned (64)));
> 
> The "packed" part is pointless here afaict.
Right. I used bit field to define control and then I found it is not necessary. 
So I removed the bit field but forget to remove packed.

>> --- a/xen/include/asm-x86/mach-default/irq_vectors.h
>> +++ b/xen/include/asm-x86/mach-default/irq_vectors.h
>> @@ -9,12 +9,13 @@
>>  #define CALL_FUNCTION_VECTOR        0xfb
>>  #define LOCAL_TIMER_VECTOR  0xfa
>>  #define PMU_APIC_VECTOR     0xf9
>> +#define POSTED_INTERRUPT_VECTOR     0xf8
> 
> Is it really necessary to use a static, high priority vector here?
There is an corner case. During vmenty, cpu will not respond external 
interrupt. And it is possible that posted interrupt and another interrupt are 
pending in IRR. We hope posted interrupt have high priority and it can be 
consumed immediately after vmentry finished. Or else, there may two separate 
interrupt arrived in hypervisor.

Best regards,
Yang



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel