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From: Paolo Bonzini <pbonzini@redhat.com>
To: "Yang Zhang" <yang.zhang.wz@gmail.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: "Lan, Tianyu" <tianyu.lan@intel.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Jan Kiszka <jan.kiszka@web.de>, Peter Xu <peterx@redhat.com>
Subject: Re: [PATCH v2 11/13] KVM: x86: add KVM_CAP_X2APIC_API
Date: Mon, 11 Jul 2016 12:40:02 +0200	[thread overview]
Message-ID: <1084e9f1-f461-8104-0c47-6e9dd3ac7787@redhat.com> (raw)
In-Reply-To: <813844d3-d644-a213-23b1-4d6648e8a8f4@gmail.com>



On 11/07/2016 12:33, Yang Zhang wrote:
> On 2016/7/11 17:17, Paolo Bonzini wrote:
>> On 11/07/2016 10:56, Yang Zhang wrote:
>>> On 2016/7/11 15:44, Paolo Bonzini wrote:
>>>> On 11/07/2016 08:06, Yang Zhang wrote:
>>>> If interrupt remapping is on, KVM_CAP_X2APIC_API is needed even with 8
>>>> VCPUs, I think.  Otherwise KVM will believe that 0xff is "broadcast"
>>>> rather than "cluster 0, CPUs 0-7".
>>>
>>> If interrupt remapping is using, what 0xff means is relying on which
>>> mode the destination CPU is in. I think there is no KVM_CAP_X2APIC_API
>>> needed since interrupt remapping table gives all the information.
>>
>> If you have EIM 0xff never means broadcast, but KVM sees a 0xff in the
>> interrupt route or KVM_SIGNAL_MSI argument and translates it into a
>> broadcast.
> 
> I see your point. I thought there would be a new irq router(like
> KVM_IRQ_ROUTING_IR) to handle all interrupts after turn on IR and
> KVM_CAP_X2APIC_API would be dropped.

KVM_CAP_X2APIC_API seems simpler to me than a new type of irq routing.

> So we will continue to use
> KVM_IRQ_ROUTING_IRQCHIP and KVM_IRQ_ROUTING_MSI for interrupt from IR,
> right?

Actually only KVM_IRQ_ROUTING_MSI, because that's the only one that is
available with split irqchip.

Paolo

  reply	other threads:[~2016-07-11 10:40 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-07 17:15 [PATCH v2 00/13] KVM: x86: break the xAPIC barrier Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 01/13] KVM: x86: bump KVM_SOFT_MAX_VCPUS to 240 Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 02/13] KVM: x86: add kvm_apic_map_get_dest_lapic Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 03/13] KVM: x86: use physical LAPIC array for logical x2APIC Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 04/13] KVM: x86: dynamic kvm_apic_map Radim Krčmář
2016-07-11  6:07   ` Yang Zhang
2016-07-11  7:43     ` Paolo Bonzini
2016-07-11 10:14       ` Yang Zhang
2016-07-11 13:48         ` Radim Krčmář
2016-07-11 14:14           ` Paolo Bonzini
2016-07-11 15:52             ` Radim Krčmář
2016-07-11 16:04               ` Paolo Bonzini
2016-07-12  3:27               ` Yang Zhang
2016-07-07 17:15 ` [PATCH v2 05/13] KVM: x86: use generic function for MSI parsing Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 06/13] KVM: x86: use hardware-compatible format for APIC ID register Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 07/13] KVM: x86: reset APIC ID when enabling LAPIC Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 08/13] KVM: VMX: optimize APIC ID read with APICv Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 09/13] KVM: x86: reset lapic base in kvm_lapic_reset Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 10/13] KVM: pass struct kvm to kvm_set_routing_entry Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 11/13] KVM: x86: add KVM_CAP_X2APIC_API Radim Krčmář
2016-07-11  6:06   ` Yang Zhang
2016-07-11  7:44     ` Paolo Bonzini
2016-07-11  8:56       ` Yang Zhang
2016-07-11  9:17         ` Paolo Bonzini
2016-07-11 10:33           ` Yang Zhang
2016-07-11 10:40             ` Paolo Bonzini [this message]
2016-07-07 17:15 ` [PATCH v2 12/13] KVM: x86: bump MAX_VCPUS to 288 Radim Krčmář
2016-07-07 17:15 ` [PATCH v2 13/13] KVM: x86: bump KVM_MAX_VCPU_ID to 1023 Radim Krčmář
2016-07-08 10:00 ` [PATCH v2 00/13] KVM: x86: break the xAPIC barrier Paolo Bonzini
2016-07-08 16:29 ` Radim Krčmář
2016-07-08 16:30   ` Paolo Bonzini

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