[PATCH v3 15/36] KVM: arm64: gic-v5: Implement GICv5 load/put and save/restore

[Sascha Bischoff]

On Mon, 2026-01-12 at 15:49 +0000, Jonathan Cameron wrote:
> On Fri, 9 Jan 2026 17:04:44 +0000
> Sascha Bischoff <Sascha.Bischoff at arm.com> wrote:
> 
> > This change introduces GICv5 load/put. Additionally, it plumbs in
> > save/restore for:
> > 
> > * PPIs (ICH_PPI_x_EL2 regs)
> > * ICH_VMCR_EL2
> > * ICH_APR_EL2
> > * ICC_ICSR_EL1
> > 
> > A GICv5-specific enable bit is added to struct vgic_vmcr as this
> > differs from previous GICs. On GICv5-native systems, the VMCR only
> > contains the enable bit (driven by the guest via ICC_CR0_EL1.EN)
> > and
> > the priority mask (PCR).
> > 
> > A struct gicv5_vpe is also introduced. This currently only contains
> > a
> > single field - bool resident - which is used to track if a VPE is
> > currently running or not, and is used to avoid a case of double
> > load
> > or double put on the WFI path for a vCPU. This struct will be
> > extended
> > as additional GICv5 support is merged, specifically for VPE
> > doorbells.
> > 
> > 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>
> 
> One comment below.
> 
> > ---
> >  arch/arm64/kvm/hyp/nvhe/switch.c   | 12 +++++
> >  arch/arm64/kvm/vgic/vgic-mmio.c    | 28 +++++++----
> >  arch/arm64/kvm/vgic/vgic-v5.c      | 74
> > ++++++++++++++++++++++++++++++
> >  arch/arm64/kvm/vgic/vgic.c         | 32 ++++++++-----
> >  arch/arm64/kvm/vgic/vgic.h         |  7 +++
> >  include/kvm/arm_vgic.h             |  2 +
> >  include/linux/irqchip/arm-gic-v5.h |  5 ++
> >  7 files changed, 141 insertions(+), 19 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c
> > b/arch/arm64/kvm/hyp/nvhe/switch.c
> > index c23e22ffac080..bc446a5d94d68 100644
> > --- a/arch/arm64/kvm/hyp/nvhe/switch.c
> > +++ b/arch/arm64/kvm/hyp/nvhe/switch.c
> > @@ -113,6 +113,12 @@ static void __deactivate_traps(struct kvm_vcpu
> > *vcpu)
> >  /* Save VGICv3 state on non-VHE systems */
> >  static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
> >  {
> > +	if (kern_hyp_va(vcpu->kvm)->arch.vgic.vgic_model ==
> > KVM_DEV_TYPE_ARM_VGIC_V5) {
> 
> Why can't you use the helper? e.g
> 
> 	if (vgic_is_v5(kern_hyp_va(vcpu->kvm))) {
> Whilst kvm/arm_vgic.h isn't directly included here other stuff from
> that header
> is in use like kvm_vgic_global_state.

I can and have now - as part of the one of the previous sets of
reviews, the header file containing the vgic_is_v5() helper changed (I
think v1->v2). Previously, it was not trivially usable here, but now it
is.

Thanks,
Sascha

> 
> 
> > +		__vgic_v5_save_state(&vcpu-
> > >arch.vgic_cpu.vgic_v5);
> > +		__vgic_v5_save_ppi_state(&vcpu-
> > >arch.vgic_cpu.vgic_v5);
> > +		return;
> > +	}
> > +
> >  	if
> > (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
> >  		__vgic_v3_save_state(&vcpu-
> > >arch.vgic_cpu.vgic_v3);
> >  		__vgic_v3_deactivate_traps(&vcpu-
> > >arch.vgic_cpu.vgic_v3);
> > @@ -122,6 +128,12 @@ static void __hyp_vgic_save_state(struct
> > kvm_vcpu *vcpu)
> >  /* Restore VGICv3 state on non-VHE systems */
> >  static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
> >  {
> > +	if (kern_hyp_va(vcpu->kvm)->arch.vgic.vgic_model ==
> > KVM_DEV_TYPE_ARM_VGIC_V5) {
> > +		__vgic_v5_restore_state(&vcpu-
> > >arch.vgic_cpu.vgic_v5);
> > +		__vgic_v5_restore_ppi_state(&vcpu-
> > >arch.vgic_cpu.vgic_v5);
> > +		return;
> > +	}
> > +
> 
> 
>