[PATCH v2 33/36] KVM: arm64: gic-v5: Probe for GICv5 device

[Jonathan Cameron]

On Fri, 19 Dec 2025 15:52:47 +0000
Sascha Bischoff <Sascha.Bischoff at arm.com> wrote:

> The basic GICv5 PPI support is now complete. Allow probing for a
> native GICv5 rather than just the legacy support.
> 
> The implementation doesn't support protected VMs with GICv5 at this
> time. Therefore, if KVM has protected mode enabled the native GICv5
> init is skipped, but legacy VMs are allowed if the hardware supports
> it.
> 
> At this stage the GICv5 KVM implementation only supports PPIs, and
> doesn't interact with the host IRS at all. This means that there is no
> need to check how many concurrent VMs or vCPUs per VM are supported by
> the IRS - the PPI support only requires the CPUIF. The support is
> artificially limited to VGIC_V5_MAX_CPUS, i.e. 512, vCPUs per VM.
> 
> With this change it becomes possible to run basic GICv5-based VMs,
> provided that they only use PPIs.
> 
> Co-authored-by: Timothy Hayes <timothy.hayes at arm.com>
> Signed-off-by: Timothy Hayes <timothy.hayes at arm.com>
> Signed-off-by: Sascha Bischoff <sascha.bischoff at arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>