[13/14] KVM: arm64: Allow userspace to request KVM_ARM_VCPU_EL2*

Commit Message

Marc Zyngier Feb. 15, 2025, 5:38 p.m. UTC

Since we're (almost) feature complete, let's allow userspace to
request KVM_ARM_VCPU_EL2* by bumping KVM_VCPU_MAX_FEATURES up.

We also now advertise the features to userspace with a new capabilities.

It's going to be great...

Signed-off-by: Marc Zyngier <[e-mail]>
---
 arch/arm64/include/asm/kvm_host.h | 2 +-
 arch/arm64/kvm/arm.c              | 6 ++++++
 include/uapi/linux/kvm.h          | 2 ++
 3 files changed, 9 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7cfa024de4e34..2a9ab9abf0f81 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -39,7 +39,7 @@ 
 
 #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
 
-#define KVM_VCPU_MAX_FEATURES 7
+#define KVM_VCPU_MAX_FEATURES 9
 #define KVM_VCPU_VALID_FEATURES	(BIT(KVM_VCPU_MAX_FEATURES) - 1)
 
 #define KVM_REQ_SLEEP \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4746c6cace2a8..6554379cdcada 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -359,6 +359,12 @@  int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_ARM_EL1_32BIT:
 		r = cpus_have_final_cap(ARM64_HAS_32BIT_EL1);
 		break;
+	case KVM_CAP_ARM_EL2:
+		r = cpus_have_final_cap(ARM64_HAS_NESTED_VIRT);
+		break;
+	case KVM_CAP_ARM_EL2_E2H0:
+		r = cpus_have_final_cap(ARM64_HAS_HCR_NV1);
+		break;
 	case KVM_CAP_GUEST_DEBUG_HW_BPS:
 		r = get_num_brps();
 		break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 45e6d8fca9b99..9a6674f51b8be 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -929,6 +929,8 @@  struct kvm_enable_cap {
 #define KVM_CAP_PRE_FAULT_MEMORY 236
 #define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237
 #define KVM_CAP_X86_GUEST_MODE 238
+#define KVM_CAP_ARM_EL2 239
+#define KVM_CAP_ARM_EL2_E2H0 240
 
 struct kvm_irq_routing_irqchip {
 	__u32 irqchip;