[PATCH v6 52/64] KVM: arm64: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT

Marc Zyngier
2022-01-28T13:28:02Z

Since we're (almost) feature complete, let's allow userspace to
request KVM_ARM_VCPU_NESTED_VIRT by bumping the KVM_VCPU_MAX_FEATURES
up. We also now advertise the feature to userspace with a new capability.

It's going to be great...

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kvm/arm.c | 3 +++
include/uapi/linux/kvm.h | 1 +
3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6bfdb21c0d8a..0ea8cf0eeca7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -37,7 +37,7 @@

#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS

-#define KVM_VCPU_MAX_FEATURES 7
+#define KVM_VCPU_MAX_FEATURES 8

#define KVM_REQ_SLEEP \
KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 91fb7bc09b8e..ac7d89c1e987 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -258,6 +258,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_ARM_EL1_32BIT:
r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);
break;
+ case KVM_CAP_ARM_EL2:
+ r = cpus_have_const_cap(ARM64_HAS_NESTED_VIRT);
+ 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 9563d294f181..6950497e5032 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1133,6 +1133,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206
#define KVM_CAP_VM_GPA_BITS 207
#define KVM_CAP_XSAVE2 208
+#define KVM_CAP_ARM_EL2 209

#ifdef KVM_CAP_IRQ_ROUTING