Re: [PATCH v7 3/5] hw/arm/smmuv3-accel: Allocate vEVENTQ for accelerated SMMUv3 devices

[Jonathan Cameron via <qemu-arm@nongnu.org>]

On Thu, 19 Feb 2026 09:01:01 +0000
Shameer Kolothum <skolothumtho@nvidia.com> wrote:

> From: Nicolin Chen <nicolinc@nvidia.com>
> 
> When the guest enables the Event Queue and a vIOMMU is present, allocate a
> vEVENTQ object so that host-side events related to the vIOMMU can be
> received and propagated back to the guest.
> 
> For cold-plugged devices using SMMUv3 acceleration, the vIOMMU is created
> before the guest boots. In this case, the vEVENTQ is allocated when the
> guest writes to SMMU_CR0 and sets EVENTQEN = 1.
> 
> If no cold-plugged device exists at boot (i.e. no vIOMMU initially), the
> vEVENTQ is allocated when a vIOMMU is created, i.e. during the first
> device hot-plug.

Why do it differently?

> 
> Errors from command queue consumption and vEVENTQ allocation are reported
> independently as the two operations are unrelated.
> 
> Event read and propagation will be added in a later patch.
> 
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>