[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Int
From: |
Radim Krčmář |
Subject: |
Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU |
Date: |
Fri, 19 Feb 2016 17:22:33 +0100 |
2016-02-19 12:43+0100, Jan Kiszka:
> On 2016-02-19 12:34, Peter Xu wrote:
>> On Fri, Feb 19, 2016 at 10:58:12AM +0100, Paolo Bonzini wrote:
>>>
>>> The source ID can be passed to the IOMMU using the MemTxAttrs mechanism.
>>
>> I see that MemTxAttrs is not enabled yet? It's dropped in all the
>> accessors like memory_region_write_accessor()?
>
> That would be a pity. How much work remains to fix that? Putting Peter
> Maydell on CC who apparently started this extension.
memory_region_dispatch_write() uses write_with_attrs, so I think we only
need to use one for MSI region and add attributes to direct writers
(like HPET and IOAPIC, because normal PCI devices should be passing
correct attributes).
> ...
>>> FWIW, Radim was thinking of interrupt remapping in the kvm-ioapic, which
>>> we have decided to set aside.
>
>> Does it mean that we are planning not to support kernel_irqchip for
>> IR? Any quick reason?
>
> The reason to split up the kernel irqchip is to reduce code complexity
> and, thus, attack surface of the kernel-side interface towards the
> guest. So, extending the "classic" in-kernel support with yet another
> feature is not really supporting that goal.
A fear of regressions after forcing people to switch from kernel ioapic
to qemu ioapic is the only argument for in-kernel support.
We'd like to use split irqchip even without IR.
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, (continued)
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Peter Xu, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Peter Xu, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Paolo Bonzini, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Peter Xu, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Peter Xu, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/19
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU,
Radim Krčmář <=
- Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Jan Kiszka, 2016/02/20
Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU, Radim Krčmář, 2016/02/19