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Re: [Qemu-devel] [PATCH v11 00/28] IOMMU: Enable interrupt remapping for
From: |
Radim Krčmář |
Subject: |
Re: [Qemu-devel] [PATCH v11 00/28] IOMMU: Enable interrupt remapping for Intel IOMMU |
Date: |
Fri, 8 Jul 2016 20:06:12 +0200 |
2016-07-08 18:36+0200, Paolo Bonzini:
> On 08/07/2016 18:01, Radim Krčmář wrote:
>> The patchset doesn't work with if you have 16 APICs with IDs 0-15 and
>> then some more, because KVM has hacked x2APIC support that translates
>> logical interrupt with destination 0xff (first cluster of 16 VCPUs) into
>> a broadcast (also works with lowest-priority) and then picks VCPU > 16
>> as the destination, leading to messages like
>>
>> do_IRQ: 17.209 No irq handler for vector
>>
>> The fun part is that this is how KVM wanted to behave, when it allowed
>> x2apic with unremapped ioapic. :(
>> KVM could either finally remove x2apic without IR or add a way in which
>> userspace could say whether an interrupt is x2APIC or not.
>>
>> QEMU cannot do anything to work around the bug, so I think it would be
>> best to disable EIM for now.
>
> What's the state of QEMU support for KVM_CAP_X2APIC_API? If it can make
> it for hard freeze, it's not a showstopper for Peter's patch.
It works and is of postable quality, but the series bases on outdated
Igor's ACPI patches. Rebasing KVM_CAP_X2APIC_API on top of IOMMU would
not complicate the situation too much and has good chances of getting in
before the hard freeze. I'll coordinate with Igor on Monday.
- [Qemu-devel] [PATCH v11 21/28] intel_iommu: add SID validation for IR, (continued)
- [Qemu-devel] [PATCH v11 21/28] intel_iommu: add SID validation for IR, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 22/28] kvm-irqchip: simplify kvm_irqchip_add_msi_route, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 23/28] kvm-irqchip: i386: add hook for add/remove virq, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 24/28] kvm-irqchip: x86: add msi route notify fn, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 25/28] kvm-irqchip: do explicit commit when update irq, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 26/28] intel_iommu: support all masks in interrupt entry cache invalidation, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 27/28] kvm-all: add trace events for kvm irqchip ops, Peter Xu, 2016/07/05
- [Qemu-devel] [PATCH v11 28/28] intel_iommu: disallow kernel-irqchip=on with IR, Peter Xu, 2016/07/05
- Re: [Qemu-devel] [PATCH v11 00/28] IOMMU: Enable interrupt remapping for Intel IOMMU, Radim Krčmář, 2016/07/08