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Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to IOMMU A
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to IOMMU API |
Date: |
Tue, 22 May 2018 18:51:07 +0100 |
On 22 May 2018 at 18:42, Richard Henderson <address@hidden> wrote:
> On 05/21/2018 07:03 AM, Peter Maydell wrote:
>> + /* Return the IOMMU index to use for a given set of transaction
>> attributes.
>> + *
>> + * Optional method: if an IOMMU only supports a single IOMMU index then
>> + * the default implementation of memory_region_iommu_attrs_to_index()
>> + * will return 0.
>> + *
>> + * The indexes supported by an IOMMU must be contiguous, starting at 0.
>> + *
>> + * @iommu: the IOMMUMemoryRegion
>> + * @attrs: memory transaction attributes
>> + */
>> + int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs);
>> +
>> + /* Return the number of IOMMU indexes this IOMMU supports.
>> + *
>> + * Optional method: if this method is not provided, then
>> + * memory_region_iommu_num_indexes() will return 1, indicating that
>> + * only a single IOMMU index is supported.
>> + */
>
> The mispatched callback has been discussed, but would it be equally useful to
> simply have a variable here instead of a callback? Perhaps max_index instead
> of num_indexes so that zero-initialization of the structure does the right
> thing for existing iommu's.
That wouldn't allow for multiple instances of the same class where the
answer is different (eg "my_iommu->has_trustzone_support ? 2 : 1" where
the answer depends on how the instance is configured via QOM properties).
thanks
-- PMM
- Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to IOMMU API, (continued)
Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to IOMMU API, Auger Eric, 2018/05/22
Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to IOMMU API, Richard Henderson, 2018/05/22
[Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/05/21
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Paolo Bonzini, 2018/05/21
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/05/21
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Paolo Bonzini, 2018/05/30
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/05/30
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Paolo Bonzini, 2018/05/31
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/05/31
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Paolo Bonzini, 2018/05/31
- Re: [Qemu-devel] [PATCH 23/27] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/05/31