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Message-ID: <20251217101125.91098-15-steven.price@arm.com>
Date: Wed, 17 Dec 2025 10:10:51 +0000
From: Steven Price <steven.price@....com>
To: kvm@...r.kernel.org,
kvmarm@...ts.linux.dev
Cc: Steven Price <steven.price@....com>,
Catalin Marinas <catalin.marinas@....com>,
Marc Zyngier <maz@...nel.org>,
Will Deacon <will@...nel.org>,
James Morse <james.morse@....com>,
Oliver Upton <oliver.upton@...ux.dev>,
Suzuki K Poulose <suzuki.poulose@....com>,
Zenghui Yu <yuzenghui@...wei.com>,
linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org,
Joey Gouly <joey.gouly@....com>,
Alexandru Elisei <alexandru.elisei@....com>,
Christoffer Dall <christoffer.dall@....com>,
Fuad Tabba <tabba@...gle.com>,
linux-coco@...ts.linux.dev,
Ganapatrao Kulkarni <gankulkarni@...amperecomputing.com>,
Gavin Shan <gshan@...hat.com>,
Shanker Donthineni <sdonthineni@...dia.com>,
Alper Gun <alpergun@...gle.com>,
"Aneesh Kumar K . V" <aneesh.kumar@...nel.org>,
Emi Kisanuki <fj0570is@...itsu.com>,
Vishal Annapurve <vannapurve@...gle.com>
Subject: [PATCH v12 14/46] arm64: RMI: Support for the VGIC in realms
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@....com>
---
Changes from v11:
* Minor changes to align with the previous patches. Note that the VGIC
handling will change with RMM v2.0.
Changes from v10:
* Make sure we sync the VGIC v4 state, and only populate valid lrs from
the list.
Changes from v9:
* Copy gicv3_vmcr from the RMM at the same time as gicv3_hcr rather
than having to handle that as a special case.
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_rmi.h | 1 +
arch/arm64/kvm/arm.c | 11 +++++--
arch/arm64/kvm/rmi.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 +++++++++++++++++++++++++++++---
arch/arm64/kvm/vgic/vgic.h | 2 ++
7 files changed, 65 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index dbb4b97d5d42..6190d75cc615 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -87,6 +87,7 @@ struct realm_rec {
void kvm_init_rmi(void);
u32 kvm_realm_ipa_limit(void);
+u32 kvm_realm_vgic_nr_lr(void);
int kvm_init_realm_vm(struct kvm *kvm);
int kvm_activate_realm(struct kvm *kvm);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 512d0ec9de60..66f23b8b3144 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -723,19 +723,24 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
kvm_call_hyp_nvhe(__pkvm_vcpu_put);
}
+ kvm_timer_vcpu_put(vcpu);
+ kvm_vgic_put(vcpu);
+
+ vcpu->cpu = -1;
+
+ if (vcpu_is_rec(vcpu))
+ return;
+
kvm_vcpu_put_debug(vcpu);
kvm_arch_vcpu_put_fp(vcpu);
if (has_vhe())
kvm_vcpu_put_vhe(vcpu);
- kvm_timer_vcpu_put(vcpu);
- kvm_vgic_put(vcpu);
kvm_vcpu_pmu_restore_host(vcpu);
if (vcpu_has_nv(vcpu))
kvm_vcpu_put_hw_mmu(vcpu);
kvm_arm_vmid_clear_active();
vcpu_clear_on_unsupported_cpu(vcpu);
- vcpu->cpu = -1;
}
static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 27ecd7d9f757..275b266c6614 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -77,6 +77,11 @@ u32 kvm_realm_ipa_limit(void)
return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ);
}
+u32 kvm_realm_vgic_nr_lr(void)
+{
+ return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS);
+}
+
static int get_start_level(struct realm *realm)
{
/*
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index dc9f9db31026..bb1a876bf298 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -82,7 +82,7 @@ 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 c9ff4f90c975..f01dd30330e3 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -982,10 +982,10 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
return;
}
- if (likely(!is_protected_kvm_enabled()))
+ if (likely(!is_protected_kvm_enabled()) && !vcpu_is_rec(vcpu))
kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if);
- if (has_vhe())
+ if (has_vhe() && !vcpu_is_rec(vcpu))
__vgic_v3_activate_traps(cpu_if);
WARN_ON(vgic_v4_load(vcpu));
@@ -1004,6 +1004,6 @@ void vgic_v3_put(struct kvm_vcpu *vcpu)
kvm_call_hyp(__vgic_v3_save_aprs, cpu_if);
WARN_ON(vgic_v4_put(vcpu));
- if (has_vhe())
+ if (has_vhe() && !vcpu_is_rec(vcpu))
__vgic_v3_deactivate_traps(cpu_if);
}
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 2fdcef3d28d1..b317b2a9815f 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -10,6 +10,7 @@
#include <linux/list_sort.h>
#include <linux/nospec.h>
+#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include "vgic.h"
@@ -994,10 +995,26 @@ static inline bool can_access_vgic_from_kernel(void)
return !static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) || has_vhe();
}
+static inline void vgic_rmm_save_state(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+ int i;
+
+ for (i = 0; i < kvm_vcpu_vgic_nr_lr(vcpu); i++) {
+ cpu_if->vgic_lr[i] = vcpu->arch.rec.run->exit.gicv3_lrs[i];
+ vcpu->arch.rec.run->enter.gicv3_lrs[i] = 0;
+ }
+
+ cpu_if->vgic_hcr = vcpu->arch.rec.run->exit.gicv3_hcr;
+ cpu_if->vgic_vmcr = vcpu->arch.rec.run->exit.gicv3_vmcr;
+}
+
static inline void vgic_save_state(struct kvm_vcpu *vcpu)
{
if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
vgic_v2_save_state(vcpu);
+ else if (vcpu_is_rec(vcpu))
+ vgic_rmm_save_state(vcpu);
else
__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
}
@@ -1032,10 +1049,30 @@ void kvm_vgic_process_async_update(struct kvm_vcpu *vcpu)
local_irq_restore(flags);
}
+static inline void vgic_rmm_restore_state(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+ int i;
+
+ for (i = 0; i < cpu_if->used_lrs; i++) {
+ vcpu->arch.rec.run->enter.gicv3_lrs[i] = cpu_if->vgic_lr[i];
+ /*
+ * Also populate the rec.run->exit copies so that a late
+ * decision to back out from entering the realm doesn't cause
+ * the state to be lost
+ */
+ vcpu->arch.rec.run->exit.gicv3_lrs[i] = cpu_if->vgic_lr[i];
+ }
+
+ vcpu->arch.rec.run->enter.gicv3_hcr = cpu_if->vgic_hcr & RMI_PERMITTED_GICV3_HCR_BITS;
+}
+
static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
vgic_v2_restore_state(vcpu);
+ else if (vcpu_is_rec(vcpu))
+ vgic_rmm_restore_state(vcpu);
else
__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
}
@@ -1088,8 +1125,10 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
void kvm_vgic_load(struct kvm_vcpu *vcpu)
{
- if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
- if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm) ||
+ !vgic_initialized(vcpu->kvm))) {
+ if (has_vhe() && !vcpu_is_rec(vcpu) &&
+ static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
return;
}
@@ -1102,8 +1141,10 @@ void kvm_vgic_load(struct kvm_vcpu *vcpu)
void kvm_vgic_put(struct kvm_vcpu *vcpu)
{
- if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
- if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm) ||
+ !vgic_initialized(vcpu->kvm))) {
+ if (has_vhe() && !vcpu_is_rec(vcpu) &&
+ static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
return;
}
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 55a1142efc6f..282a9701dea6 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -245,6 +245,8 @@ struct ap_list_summary {
static inline int kvm_vcpu_vgic_nr_lr(struct kvm_vcpu *vcpu)
{
+ if (unlikely(vcpu_is_rec(vcpu)))
+ return kvm_realm_vgic_nr_lr();
return kvm_vgic_global_state.nr_lr;
}
--
2.43.0
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