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Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs fo
From: |
David Kiarie |
Subject: |
Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR |
Date: |
Mon, 30 May 2016 12:25:55 +0300 |
On Mon, May 30, 2016 at 12:16 PM, Peter Xu <address@hidden> wrote:
> On Mon, May 30, 2016 at 11:54:52AM +0300, David Kiarie wrote:
>> On Mon, May 30, 2016 at 11:14 AM, Peter Xu <address@hidden> wrote:
>> > On Mon, May 30, 2016 at 07:56:16AM +0200, Jan Kiszka wrote:
>> >> On 2016-05-30 07:45, Peter Xu wrote:
> [...]
>> >> >
>> >> > I assume you mean when host cpu is big endian. x86 was little endian,
>> >> > and I was testing on x86.
>> >> >
>> >> > I think you are right. I should do conditional byte swap for all
>> >> > uint{16/32/64} cases within the fields. For example, index_l field in
>> >> > above VTD_IR_MSIAddress. And there are several other cases that need
>> >> > special treatment in the patchset. Will go over and fix corresponding
>> >> > issues in next version.
>> >>
>> >> You actually need bit-swap with bit fields, see e.g. hw/net/vmxnet3.h.
>> >
>> > Not noticed about bit-field ordering before... So maybe I need both?
>>
>> Yes, I think we will need both though, I think, byte swapping the
>> whole struct will break the code but swapping individual fields is
>> what we need.
>>
>> Myself, I'm defining bitfields as below:
>>
>> struct CMDCompletionWait {
>>
>> #ifdef __BIG_ENDIAN_BITFIELD
>> uint32_t type:4; /* command type */
>> uint32_t reserved:8;
>> uint64_t store_addr:49; /* addr to write */
>> uint32_t completion_flush:1; /* allow more executions */
>> uint32_t completion_int:1; /* set MMIOWAITINT */
>> uint32_t completion_store:1; /* write data to address */
>
> I guess what we need might be this one:
>
> uint64_t type:4; /* command type */
> uint64_t reserved:8;
> uint64_t store_addr:49; /* addr to write */
> uint64_t completion_flush:1; /* allow more executions */
> uint64_t completion_int:1; /* set MMIOWAITINT */
> uint64_t completion_store:1; /* write data to address */
>
> IIUC, if we define type:4 as uint32_t rather than uint64_t, it should
> be bits [29:32] of the struct on big endian machines, not bits
> [61:64].
Yes, you're right.
>
> Thanks,
>
> -- peterx
- Re: [Qemu-devel] [PATCH v7 08/25] x86-iommu: introduce parent class, (continued)
[Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, Peter Xu, 2016/05/17
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, David Kiarie, 2016/05/29
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, David Kiarie, 2016/05/29
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, Peter Xu, 2016/05/30
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, Jan Kiszka, 2016/05/30
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, Peter Xu, 2016/05/30
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, David Kiarie, 2016/05/30
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR, Peter Xu, 2016/05/30
- Re: [Qemu-devel] [PATCH v7 07/25] intel_iommu: define several structs for IOMMU IR,
David Kiarie <=
[Qemu-devel] [PATCH v7 10/25] x86-iommu: q35: generalize find_add_as(), Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 09/25] x86-iommu: provide x86_iommu_get_default, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 11/25] intel_iommu: add IR translation faults defines, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 12/25] intel_iommu: Add support for PCI MSI remap, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 13/25] q35: ioapic: add support for emulated IOAPIC IR, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 14/25] ioapic: introduce ioapic_entry_parse() helper, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 15/25] intel_iommu: add support for split irqchip, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 17/25] x86-iommu: introduce IEC notifiers, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 16/25] q35: add "intremap" parameter to enable IR, Peter Xu, 2016/05/17
[Qemu-devel] [PATCH v7 19/25] intel_iommu: Add support for Extended Interrupt Mode, Peter Xu, 2016/05/17