[PATCH v19 07/20] KVM: arm64: Add vcpu load/put call backs for flavors
Suzuki K Poulose
suzuki.poulose at arm.com
Sun Sep 20 14:28:32 PDT 2026
Add VM flavor specific handlers for VCPU load/put, in an effort to make it
easier to follow the code. pauth traps were removed from VMs running PKVM
as it is a no-op for them.
Based on a patch by Marc Zyngier
Suggested-by: Marc Zyngier <maz at kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
---
Changes since v17:
- Use macro to initialize the per-flavor ops
- Add a wrapper to initialise ops in the vcpu structure.
- Add BUILD_BUG_ON for the array size
- Remove irrelevant comment about the order of timer loading for !VHE
- Use the explicti kvm_call_hyp_nvhe for nVHE flavor
- Don't call nvhe_vcpu_put from pkvm_vcpu_put, open code them
- Drop cpu argument for vcpu_load() callback. We set the cpu
before the callbacks are invoked
---
arch/arm64/include/asm/kvm_host.h | 6 ++
arch/arm64/kvm/arm.c | 134 ++++++++++++++++++++++++------
2 files changed, 114 insertions(+), 26 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 9b1cf9c59e81f..149f4582c8b6a 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -150,6 +150,11 @@ struct kvm_vmid {
atomic64_t id;
};
+struct kvm_vcpu_ops {
+ void (*vcpu_load)(struct kvm_vcpu *vcpu);
+ void (*vcpu_put)(struct kvm_vcpu *vcpu);
+};
+
struct kvm_s2_mmu {
struct kvm_vmid vmid;
@@ -855,6 +860,7 @@ struct vncr_tlb;
struct kvm_vcpu_arch {
struct kvm_cpu_context ctxt;
+ const struct kvm_vcpu_ops *vcpu_ops;
/*
* Guest floating point state
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c74706ed9a531..9b977dc734220 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -93,6 +93,7 @@ static const struct kvm_ioctl_cap_map vm_ioctl_caps[] = {
{ KVM_ARM_PREFERRED_TARGET, KVM_CAP_ARM_BASIC },
};
+static void kvm_init_vcpu_ops(struct kvm_vcpu *vcpu);
/*
* Set *ext to the capability.
* Return 0 if found, or -EINVAL if no IOCTL matches.
@@ -569,6 +570,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
mutex_unlock(&vcpu->mutex);
#endif
+ kvm_init_vcpu_ops(vcpu);
+
/* Force users to call KVM_ARM_VCPU_INIT */
vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
@@ -738,12 +741,9 @@ static void vcpu_load_pvtime(struct kvm_vcpu *vcpu)
kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
}
-void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+static void vhe_vcpu_load(struct kvm_vcpu *vcpu)
{
- if (!is_protected_kvm_enabled())
- vcpu_prepare_mmu(vcpu);
-
- vcpu->cpu = cpu;
+ vcpu_prepare_mmu(vcpu);
/*
* The timer must be loaded before the vgic to correctly set up physical
* interrupt deactivation in nested state (e.g. timer interrupt).
@@ -752,22 +752,53 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_vgic_load(vcpu);
kvm_vcpu_load_debug(vcpu);
kvm_vcpu_load_fgt(vcpu);
- if (has_vhe())
- kvm_vcpu_load_vhe(vcpu);
+ kvm_vcpu_load_vhe(vcpu);
kvm_arch_vcpu_load_fp(vcpu);
kvm_vcpu_pmu_restore_guest(vcpu);
vcpu_load_pvtime(vcpu);
vcpu_set_wfx_traps(vcpu);
vcpu_set_pauth_traps(vcpu);
+}
- if (is_protected_kvm_enabled()) {
- kvm_call_hyp_nvhe(__pkvm_vcpu_load,
- vcpu->kvm->arch.pkvm.handle,
- vcpu->vcpu_idx, vcpu->arch.hcr_el2);
- kvm_call_hyp(__vgic_v3_restore_vmcr_aprs,
- &vcpu->arch.vgic_cpu.vgic_v3);
- }
+static void nvhe_vcpu_load(struct kvm_vcpu *vcpu)
+{
+ vcpu_prepare_mmu(vcpu);
+ kvm_timer_vcpu_load(vcpu);
+ kvm_vgic_load(vcpu);
+ kvm_vcpu_load_debug(vcpu);
+ kvm_vcpu_load_fgt(vcpu);
+ kvm_arch_vcpu_load_fp(vcpu);
+ kvm_vcpu_pmu_restore_guest(vcpu);
+
+ vcpu_load_pvtime(vcpu);
+ vcpu_set_wfx_traps(vcpu);
+ vcpu_set_pauth_traps(vcpu);
+}
+
+static void pkvm_vcpu_load(struct kvm_vcpu *vcpu)
+{
+ kvm_timer_vcpu_load(vcpu);
+ kvm_vgic_load(vcpu);
+ kvm_vcpu_load_debug(vcpu);
+ kvm_vcpu_load_fgt(vcpu);
+ kvm_arch_vcpu_load_fp(vcpu);
+ kvm_vcpu_pmu_restore_guest(vcpu);
+
+ vcpu_load_pvtime(vcpu);
+ vcpu_set_wfx_traps(vcpu);
+
+ kvm_call_hyp_nvhe(__pkvm_vcpu_load,
+ vcpu->kvm->arch.pkvm.handle,
+ vcpu->vcpu_idx, vcpu->arch.hcr_el2);
+ kvm_call_hyp_nvhe(__vgic_v3_restore_vmcr_aprs,
+ &vcpu->arch.vgic_cpu.vgic_v3);
+}
+
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+ vcpu->cpu = cpu;
+ vcpu->arch.vcpu_ops->vcpu_load(vcpu);
if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
vcpu_set_on_unsupported_cpu(vcpu);
@@ -775,28 +806,48 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
vcpu->arch.pid = pid_nr(vcpu->pid);
}
-void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+static void vhe_vcpu_put(struct kvm_vcpu *vcpu)
{
- if (is_protected_kvm_enabled()) {
- kvm_call_hyp(__vgic_v3_save_aprs, &vcpu->arch.vgic_cpu.vgic_v3);
- kvm_call_hyp_nvhe(__pkvm_vcpu_put);
-
- /* __pkvm_vcpu_put implies a sync of the state */
- if (kvm_vm_is_unprotected_pkvm(vcpu->kvm))
- vcpu_set_flag(vcpu, PKVM_HOST_STATE_DIRTY);
- }
-
kvm_vcpu_put_debug(vcpu);
kvm_arch_vcpu_put_fp(vcpu);
- if (has_vhe())
- kvm_vcpu_put_vhe(vcpu);
+ 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();
+}
+static void nvhe_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ kvm_vcpu_put_debug(vcpu);
+ kvm_arch_vcpu_put_fp(vcpu);
+ kvm_timer_vcpu_put(vcpu);
+ kvm_vgic_put(vcpu);
+ kvm_vcpu_pmu_restore_host(vcpu);
+ kvm_arm_vmid_clear_active();
+}
+
+static void pkvm_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ kvm_call_hyp_nvhe(__vgic_v3_save_aprs, &vcpu->arch.vgic_cpu.vgic_v3);
+ kvm_call_hyp_nvhe(__pkvm_vcpu_put);
+
+ /* __pkvm_vcpu_put implies a sync of the state */
+ if (kvm_vm_is_unprotected_pkvm(vcpu->kvm))
+ vcpu_set_flag(vcpu, PKVM_HOST_STATE_DIRTY);
+
+ kvm_vcpu_put_debug(vcpu);
+ kvm_arch_vcpu_put_fp(vcpu);
+ kvm_timer_vcpu_put(vcpu);
+ kvm_vgic_put(vcpu);
+ kvm_vcpu_pmu_restore_host(vcpu);
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.vcpu_ops->vcpu_put(vcpu);
vcpu_clear_on_unsupported_cpu(vcpu);
vcpu->cpu = -1;
}
@@ -2136,6 +2187,37 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
}
}
+static const struct kvm_vcpu_ops vhe_vcpu_ops = {
+ .vcpu_load = vhe_vcpu_load,
+ .vcpu_put = vhe_vcpu_put,
+};
+
+static const struct kvm_vcpu_ops nvhe_vcpu_ops = {
+ .vcpu_load = nvhe_vcpu_load,
+ .vcpu_put = nvhe_vcpu_put,
+};
+
+static const struct kvm_vcpu_ops pkvm_vcpu_ops = {
+ .vcpu_load = pkvm_vcpu_load,
+ .vcpu_put = pkvm_vcpu_put,
+};
+
+#define KVM_VCPU_OPS(flavor, ops) \
+ [(flavor)] = (ops)
+
+static const struct kvm_vcpu_ops *arm64_vcpu_ops[] = {
+ KVM_VCPU_OPS(VM_VHE, &vhe_vcpu_ops),
+ KVM_VCPU_OPS(VM_NVHE, &nvhe_vcpu_ops),
+ KVM_VCPU_OPS(VM_PKVM, &pkvm_vcpu_ops),
+ KVM_VCPU_OPS(VM_PROTECTED_PKVM, &pkvm_vcpu_ops),
+};
+
+static void kvm_init_vcpu_ops(struct kvm_vcpu *vcpu)
+{
+ BUILD_BUG_ON(ARRAY_SIZE(arm64_vcpu_ops) != VM_FLAVOR_MAX);
+ vcpu->arch.vcpu_ops = arm64_vcpu_ops[vcpu->kvm->arch.vm_flavor];
+}
+
static unsigned long nvhe_percpu_size(void)
{
return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) -
--
2.43.0
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