On Thu, 23 Oct 2025 at 11:06, Alex Bennée <[email protected]> wrote: > tangtao1634 <[email protected]> writes: > > From: Tao Tang <[email protected]> > > A key question is, "Why introduce a new smmu-testdev instead of using an > > existing PCIe or platform device?" > > I curious what the split between PCIe and platform devices that need an > SMMU are. I suspect there is a strong split between the virtualisation > case and the emulation case.
I don't think emulation vs virtualization matters much here. My impression is that SMMU is almost entirely for PCI/PCIe; the exception is that for Realm emulation we need to do granule checks for non-PCI devices like the GIC ITS, and the easy way to do that is to have the ITS accesses go through the SMMU as a "NoStreamID" client. (Linaro has a JIRA card for the Realm/GIC interaction: https://linaro.atlassian.net/browse/QEMU-606 ) thanks -- PMM
