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From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 22 May 2018 15:19:38 +0100
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Content-Type: text/plain; charset="UTF-8"
Subject: Re: [Qemu-devel] [PATCH 14/27] iommu: Add IOMMU index concept to
 IOMMU API
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To: Auger Eric <eric.auger@redhat.com>
Cc: "patches@linaro.org" <patches@linaro.org>, QEMU Developers <qemu-devel@nongnu.org>, qemu-arm <qemu-arm@nongnu.org>, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>, Richard Henderson <rth@twiddle.net>

On 22 May 2018 at 15:11, Auger Eric <eric.auger@redhat.com> wrote:
> Hi Peter,
>
> On 05/22/2018 03:22 PM, Peter Maydell wrote:
>> How many substream IDs do we expect to see in practice?
>
> Spec says max 20 bits, matching the max size of the PASID

Right, but do we actually expect to see transactions from
devices that use the whole 2^20 possible values, or will
they in practice mostly use 1..5, or somethnig else?

thanks
-- PMM