[PATCH v9 13/43] arm64: RME: Support for the VGIC in realms
Steven Price
steven.price at arm.com
Wed Jul 9 07:42:57 PDT 2025
On 03/07/2025 14:22, Suzuki K Poulose wrote:
> On 11/06/2025 11:48, Steven Price wrote:
>> The RMM provides emulation of a VGIC to the realm guest but delegates
>> much of the handling to the host. Implement support in KVM for
>> saving/restoring state to/from the REC structure.
>>
>> Signed-off-by: Steven Price <steven.price at arm.com>
>> ---
>> Changes from v8:
>> * Propagate gicv3_hcr to from the RMM.
>> Changes from v5:
>> * Handle RMM providing fewer GIC LRs than the hardware supports.
>> ---
>> arch/arm64/include/asm/kvm_rme.h | 1 +
>> arch/arm64/kvm/arm.c | 16 +++++++++--
>> arch/arm64/kvm/rme.c | 5 ++++
>> arch/arm64/kvm/vgic/vgic-init.c | 2 +-
>> arch/arm64/kvm/vgic/vgic-v3.c | 6 +++-
>> arch/arm64/kvm/vgic/vgic.c | 49 ++++++++++++++++++++++++++++++--
>> 6 files changed, 72 insertions(+), 7 deletions(-)
>>
>
> ...
>
>> diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/
>> vgic-init.c
>> index eb1205654ac8..77b4962ebfb6 100644
>> --- a/arch/arm64/kvm/vgic/vgic-init.c
>> +++ b/arch/arm64/kvm/vgic/vgic-init.c
>> @@ -81,7 +81,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
>> * the proper checks already.
>> */
>> if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
>> - !kvm_vgic_global_state.can_emulate_gicv2)
>> + (!kvm_vgic_global_state.can_emulate_gicv2 || kvm_is_realm(kvm)))
>> return -ENODEV;
>> /*
>> diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-
>> v3.c
>> index b9ad7c42c5b0..c10ad817030d 100644
>> --- a/arch/arm64/kvm/vgic/vgic-v3.c
>> +++ b/arch/arm64/kvm/vgic/vgic-v3.c
>> @@ -8,9 +8,11 @@
>> #include <linux/kvm_host.h>
>> #include <linux/string_choices.h>
>> #include <kvm/arm_vgic.h>
>> +#include <asm/kvm_emulate.h>
>> #include <asm/kvm_hyp.h>
>> #include <asm/kvm_mmu.h>
>> #include <asm/kvm_asm.h>
>> +#include <asm/rmi_smc.h>
>> #include "vgic.h"
>> @@ -758,7 +760,9 @@ void vgic_v3_put(struct kvm_vcpu *vcpu)
>> return;
>> }
>> - if (likely(!is_protected_kvm_enabled()))
>> + if (vcpu_is_rec(vcpu))
>> + cpu_if->vgic_vmcr = vcpu->arch.rec.run->exit.gicv3_vmcr;
>> + else if (likely(!is_protected_kvm_enabled()))
>
> This function is never reached for Realms, this should be folded in
> vgic_rmm_save_state(). See below.
Good catch - I can drop the changes in this file and handle VMCR in
vgic_rmm_save_state().
Thanks,
Steve
>
>> kvm_call_hyp(__vgic_v3_save_vmcr_aprs, cpu_if);
>> WARN_ON(vgic_v4_put(vcpu));
>> diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
>> index c7aed48c5668..2908b4610c4e 100644
>> --- a/arch/arm64/kvm/vgic/vgic.c
>> +++ b/arch/arm64/kvm/vgic/vgic.c
>
> ...
>
>> void kvm_vgic_put(struct kvm_vcpu *vcpu)
>> {
>> - if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !
>> vgic_initialized(vcpu->kvm))) {
>> + if (unlikely(vcpu_is_rec(vcpu)))
>> + return;
>
> ^^^
>
>> + if (unlikely(!irqchip_in_kernel(vcpu->kvm) ||
>> + !vgic_initialized(vcpu->kvm))) {
>> if (has_vhe() &&
>> static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
>> __vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
>> return;
>
> Suzuki
More information about the linux-arm-kernel
mailing list