Re: [PATCH] x86: let userspace inject interrupts into the local APIC

From: Paolo Bonzini
Date: Tue Mar 19 2013 - 14:39:31 EST


Il 19/03/2013 19:13, Gleb Natapov ha scritto:
>> > There is no way for userspace to inject interrupts into a VCPU's
>> > local APIC, which is important in order to inject INITs coming from
>> > the chipset. KVM_INTERRUPT is currently disabled when the in-kernel
>> > local APIC is used, so we can repurpose it. The shorthand destination
>> > field must contain APIC_DEST_SELF, which has a double effect: first,
>> > the ICR2 register is not used and the 32-bit field of KVM_INTERRUPT is
>> > enough; second, it ensures that the valid range of the irq field is
>> > distinct in the userspace-APIC and kernel-APIC cases.
>> >
> Init coming from triggering INIT# line should not be modeled as INIT coming from
> APIC.

Then Jan's patch was wrong, and INIT should not have been an apic event
(perhaps SIPI should).

> In fact INIT cannot be send using SELF shorthand.

Where does the SDM say that?

Paolo

> If APIC code will be fixed to check for that this code will break.
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