Re: [RFC PATCH v2 05/20] hw/arm/smmuv3-accel: Associate a pxb-pcie bus

[Nicolin Chen <nicolinc@nvidia.com>]

On Wed, Mar 19, 2025 at 09:26:29AM +0000, Shameerali Kolothum Thodi wrote:
> Having said that,  current code only allows pxb-pcie root complexes avoiding
> the pcie.0. The idea behind this was, user can use pcie.0 with a non accel SMMUv3
> for any emulated devices avoiding the performance bottlenecks we are
> discussing for emulated dev+smmuv3-accel cases. But based on the feedback from
> Eric and Daniel I will relax that restriction and will allow association with pcie.0.

Just want a clarification here..

If VM has a passthrough device only:
 attach it to PCIE.0 <=> vSMMU0 (accel=on)
If VM has an emulated device and a passthrough device:
 attach the emulated device to PCIE.0 <=> vSMMU bypass (or accel=off?)
 attach the passthrough device to pxb-pcie <=> vSMMU0 (accel=on)
?

Thanks
Nicolin